FASH and MASH: female and male adult human phantoms based on polygon mesh surfaces: II. Dosimetric calculations

NASA Astrophysics Data System (ADS)

Kramer, R.; Cassola, V. F.; Khoury, H. J.; Vieira, J. W.; de Melo Lima, V. J.; Robson Brown, K.

2010-01-01

Female and male adult human phantoms, called FASH (Female Adult meSH) and MASH (Male Adult meSH), have been developed in the first part of this study using 3D animation software and anatomical atlases to replace the image-based FAX06 and the MAX06 voxel phantoms. 3D modelling methods allow for phantom development independent from medical images of patients, volunteers or cadavers. The second part of this study investigates the dosimetric implications for organ and tissue equivalent doses due to the anatomical differences between the new and the old phantoms. These differences are mainly caused by the supine position of human bodies during scanning in order to acquire digital images for voxel phantom development. Compared to an upright standing person, in image-based voxel phantoms organs are often coronally shifted towards the head and sometimes the sagittal diameter of the trunk is reduced by a gravitational change of the fat distribution. In addition, volumes of adipose and muscle tissue shielding internal organs are sometimes too small, because adaptation of organ volumes to ICRP-based organ masses often occurs at the expense of general soft tissues, such as adipose, muscle or unspecified soft tissue. These effects have dosimetric consequences, especially for partial body exposure, such as in x-ray diagnosis, but also for whole body external exposure and for internal exposure. Using the EGSnrc Monte Carlo code, internal and external exposure to photons and electrons has been simulated with both pairs of phantoms. The results show differences between organ and tissue equivalent doses for the upright standing FASH/MASH and the image-based supine FAX06/MAX06 phantoms of up to 80% for external exposure and up to 100% for internal exposure. Similar differences were found for external exposure between FASH/MASH and REGINA/REX, the reference voxel phantoms of the International Commission on Radiological Protection. Comparison of effective doses for external photon exposure showed good agreement between FASH/MASH and REGINA/REX, but large differences between FASH/MASH and the mesh-based RPI_AM and the RPI_AF phantoms, developed at the Rensselaer Polytechnic Institute (RPI).

Solid cancer mortality associated with chronic external radiation exposure at the French atomic energy commission and nuclear fuel company.

PubMed

Metz-Flamant, C; Samson, E; Caër-Lorho, S; Acker, A; Laurier, D

2011-07-01

Studies of nuclear workers make it possible to directly quantify the risks associated with ionizing radiation exposure at low doses and low dose rates. Studies of the CEA (Commissariat à l'Energie Atomique) and AREVA Nuclear Cycle (AREVA NC) cohort, currently the most informative such group in France, describe the long-term risk to nuclear workers associated with external exposure. Our aim is to assess the risk of mortality from solid cancers among CEA and AREVA NC nuclear workers and its association with external radiation exposure. Standardized mortality ratios (SMRs) were calculated and internal Poisson regressions were conducted, controlling for the main confounding factors [sex, attained age, calendar period, company and socioeconomic status (SES)]. During the period 1968-2004, there were 2,035 solid cancers among the 36,769 CEA-AREVA NC workers. Cumulative external radiation exposure was assessed for the period 1950-2004, and the mean cumulative dose was 12.1 mSv. Mortality rates for all causes and all solid cancers were both significantly lower in this cohort than in the general population. A significant excess of deaths from pleural cancer, not associated with cumulative external dose, was observed, probably due to past asbestos exposure. We observed a significant excess of melanoma, also unassociated with dose. Although cumulative external dose was not associated with mortality from all solid cancers, the central estimated excess relative risk (ERR) per Sv of 0.46 for solid cancer mortality was higher than the 0.26 calculated for male Hiroshima and Nagasaki A-bomb survivors 50 years or older and exposed at the age of 30 years or older. The modification of our results after stratification for SES demonstrates the importance of this characteristic in occupational studies, because it makes it possible to take class-based lifestyle differences into account, at least partly. These results show the great potential of a further joint international study of nuclear workers, which should improve knowledge about the risks associated with chronic low doses and provide useful risk estimates for radiation protection.

Doses of external exposure in Jordan house due to gamma-emitting natural radionuclides in building materials.

PubMed

Al-Jundi, J; Ulanovsky, A; Pröhl, G

2009-10-01

The use of building materials containing naturally occurring radionuclides as (40)K, (232)Th, and (238)U and their progeny results in external exposures of the residents of such buildings. In the present study, indoor dose rates for a typical Jordan concrete room are calculated using Monte Carlo method. Uniform chemical composition of the walls, floor and ceiling as well as uniform mass concentrations of the radionuclides in walls, floor and ceiling are assumed. Using activity concentrations of natural radionuclides typical for the Jordan houses and assuming them to be in secular equilibrium with their progeny, the maximum annual effective doses are estimated to be 0.16, 0.12 and 0.22 mSv a(-1) for (40)K, (232)Th- and (238)U-series, respectively. In a total, the maximum annual effective indoor dose due to external gamma-radiation is 0.50 mSv a(-1). Additionally, organ dose coefficients are calculated for all organs considered in ICRP Publication 74. Breast, skin and eye lenses have the maximum equivalent dose rate values due to indoor exposures caused by the natural radionuclides, while equivalent dose rates for uterus, colon (LLI) and small intestine are found to be the smallest. More specifically, organ dose rates (nSv a(-1)per Bq kg(-1)) vary from 0.044 to 0.060 for (40)K, from 0.44 to 0.60 for radionuclides from (238)U-series and from 0.60 to 0.81 for radionuclides from (232)Th-series. The obtained organ and effective dose conversion coefficients can be conveniently used in practical dose assessment tasks for the rooms of similar geometry and varying activity concentrations and local-specific occupancy factors.

Contribution of internal exposures to the radiological consequences of the Chernobyl accident.

PubMed

Balonov, M I; Anspaugh, L R; Bouville, A; Likhtarev, I A

2007-01-01

The main pathways leading to exposure of members of the general public due to the Chernobyl accident were external exposure from radionuclides deposited on the ground and ingestion of contaminated terrestrial food products. The collective dose to the thyroid was nearly 1.5 million man Gy in Belarus, Russia and Ukraine with nearly half received by children and adolescents. The collective effective dose received in 1986-2005 by approximately five million residents living in the affected areas of the three countries was approximately 50,000 man Sv with approximately 40% from ingestion. That contribution might have been larger if countermeasures had not been applied. The main radionuclide contributing to both external and internal effective dose is 137Cs with smaller contributions of 134Cs and 90Sr and negligible contribution of transuranic elements. The major demonstrated radiation-caused health effect of the Chernobyl accident has been an elevated incidence of thyroid cancer in children.

Assessment of occupational exposure in a granite quarry and processing factory.

PubMed

Tejado, J J; Guillén, J; Baeza, A

2016-09-01

Workers in the granite industry face an occupational hazard: silicosis due to the crystalline silica present in inhalable dust. As granite can also present a variable, and occasionally significant, content of naturally occurring radionuclides, they may also face a radiological hazard. In order to assess the risk, a granite industry with a quarry and processing factory was selected to assess the occupational exposure. Three main potential pathways were observed: external irradiation, inhalation of granite dust, and radon exposure. The external dose rate was similar to that in a nearby farming area. A slight increment (0.016-0.076 mSv yr -1 ) was observed in the quarry and stockpile, due to quarry faces and granite blocks. The effective dose due to granite dust inhalation was 0.182  ±  0.009 mSv yr -1 in the worst case scenario (3 mg m -3 dust load in air and no use of filter masks). Thus, the mean value of the effective dose from these two pathways was 0.26 mSv yr -1 , lower than the reference level of 1 mSv yr -1 for the general population. The annual mean value of radon concentration in the indoor air was 33 Bq m -3 . However, during granite processing works the radon concentration can increase up to 216 Bq m -3 , due to mechanical operations (sawing, polishing, sanding, etc). This radon concentration was below the 600 Bq m -3 reference level for action in working places. Therefore, workers in this granite factory face no significant additional radiological exposure, and no-one needs to be designated as occupationally exposed and subject to individual dosimetry.

Radiation dose due to radon and thoron progeny inhalation in high-level natural radiation areas of Kerala, India.

PubMed

Omori, Yasutaka; Tokonami, Shinji; Sahoo, Sarata Kumar; Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Hosoda, Masahiro; Kudo, Hiromi; Pornnumpa, Chanis; Nair, Raghu Ram K; Jayalekshmi, Padmavaty Amma; Sebastian, Paul; Akiba, Suminori

2017-03-20

In order to evaluate internal exposure to radon and thoron, concentrations for radon, thoron, and thoron progeny were measured for 259 dwellings located in high background radiation areas (HBRAs, outdoor external dose: 3-5 mGy y -1 ) and low background radiation areas (control areas, outdoor external dose: 1 mGy y -1 ) in Karunagappally Taluk, Kerala, India. The measurements were conducted using passive-type radon-thoron detectors and thoron progeny detectors over two six-month measurement periods from June 2010 to June 2011. The results showed no major differences in radon and thoron progeny concentrations between the HBRAs and the control areas. The geometric mean of the annual effective dose due to radon and thoron was calculated as 0.10 and 0.44 mSv, respectively. The doses were small, but not negligible compared with the external dose in the two areas.

Assessing the Exposome with External Measures: Commentary on the State of the Science and Research Recommendations.

PubMed

Turner, Michelle C; Nieuwenhuijsen, Mark; Anderson, Kim; Balshaw, David; Cui, Yuxia; Dunton, Genevieve; Hoppin, Jane A; Koutrakis, Petros; Jerrett, Michael

2017-03-20

The exposome comprises all environmental exposures that a person experiences from conception throughout the life course. Here we review the state of the science for assessing external exposures within the exposome. This article reviews (a) categories of exposures that can be assessed externally, (b) the current state of the science in external exposure assessment, (c) current tools available for external exposure assessment, and (d) priority research needs. We describe major scientific and technological advances that inform external assessment of the exposome, including geographic information systems; remote sensing; global positioning system and geolocation technologies; portable and personal sensing, including smartphone-based sensors and assessments; and self-reported questionnaire assessments, which increasingly rely on Internet-based platforms. We also discuss priority research needs related to methodological and technological improvement, data analysis and interpretation, data sharing, and other practical considerations, including improved assessment of exposure variability as well as exposure in multiple, critical life stages.

Hair Follicle Bulb as a Biodosimeter for Low-Level VX Vapor Exposure: Initial Studies Validating the Presence of Potential Protein Biomarkers of Exposure in the Sprague-Dawley Rat Whisker Follicle

DTIC Science & Technology

2006-10-01

lead to false positive segmental hair analysis results.13 Due to the increased risk of false positives associated with segmental hair analysis ...to 200 mg of hair (to allow confirmation testing). 7 The segments are typically washed to remove external contaminants and the chemicals in the hair ...further confirmation. The method overcomes the false positives associated with traditional segmental hair analysis such. By measuring the

Personality Traits and Combat Exposure as Predictors of Psychopathology Over Time

PubMed Central

Koffel, Erin; Kramer, Mark D.; Arbisi, Paul A.; Erbes, Christopher R.; Kaler, Matthew; Polusny, Melissa A.

2016-01-01

Background Research suggests that personality traits have both direct and indirect effects on the development of psychological symptoms, with indirect effects mediated by stressful or traumatic events. This study models the direct influence of personality traits on residualized changes in internalizing and externalizing symptoms following a stressful and potentially traumatic deployment, as well as the indirect influence of personality on symptom levels mediated by combat exposure. Method We utilized structural equation modeling with a longitudinal prospective study of 522 US National Guard soldiers deployed to Iraq. Analyses were based on self-report measures of personality, combat exposure, and internalizing and externalizing symptoms. Results Both pre-deployment Disconstraint and externalizing symptoms predicted combat exposure, which in turn predicted internalizing and externalizing symptoms. There was a significant indirect effect for pre-deployment externalizing symptoms on post-deployment externalizing via combat exposure (p < .01). Negative Emotionality and pre-deployment internalizing symptoms directly predicted post-deployment internalizing symptoms, but both were unrelated to combat exposure. No direct effects of personality on residualized changes in externalizing symptoms were found. Conclusions Baseline symptom dimensions had significant direct and indirect effects on post-deployment symptoms. Controlling for both pre-exposure personality and symptoms, combat experiences remained positively related to both internalizing and externalizing symptoms. Implications for diagnostic classification are discussed. PMID:26347314

Exposure to Externalizing Peers in Early Childhood: Homophily and Peer Contagion Processes.

ERIC Educational Resources Information Center

Hanish, Laura D.; Martin, Carol Lynn; Fabes, Richard A.; Leonard, Stacie; Herzog, Melissa

2005-01-01

Guided by a transactional model, we examined the predictors and effects of exposure to externalizing peers in a low-risk sample of preschoolers and kindergarteners. On the basis of daily observations of peer interactions, we calculated measures of total exposure to externalizing peers and measures of exposure to same- and other-sex externalizing…

Estimates of the occupational exposure to tenorm in the phosphoric acid production plant in Iran.

PubMed

Fathabadi, N; Vasheghani Farahani, M; Moradi, M; Hadadi, B

2012-09-01

Phosphate rock is used world wide for manufacturing phosphoric acid and several chemical fertilisers. It is known that the phosphate rock contains various concentrations of uranium, thorium, radium and their daughters. The subject of this study is the evaluation of the radiation exposure to workers in the phosphoric acid production plant due to technologically enhanced naturally occurring radioactive materials that can result from the presence of naturally occurring radioactive materials in phosphate ores used in the manufacturing of phosphoric acid. Radiation exposure due to direct gamma radiation, dust inhalation and radon gas has been investigated and external and internal doses of exposed workers have been calculated. Natural radioactivity due to (40)K, (226)Ra and (232)Th have been measured in phosphate rock, phosphogypsum, chemical fertilisers and other samples by gamma spectrometry system with a high-purity germanium. The average concentrations of (226)Ra and (40)K observed in the phosphate rock are 760 and 80 Bq kg(-1), respectively. Annual effective dose from external radiation had a mean value of ∼0.673 mSv y(-1). Dust sampling revealed greatest values in the storage area. The annual average effective dose from inhalation of long-lived airborne was 0.113 mSv y(-1). Radon gas concentrations in the processing plant and storage area were found to be of the same value as the background. In this study the estimated annual effective doses to workers were below 1 mSv y(-1).

External magnetic field-induced selective biodistribution of magnetoliposomes in mice

NASA Astrophysics Data System (ADS)

García-Jimeno, Sonia; Escribano, Elvira; Queralt, Josep; Estelrich, Joan

2012-08-01

This study looked at the effect of an external magnet on the biodistribution of magnetoliposomes intravenously administrated in mice (8 mg iron/kg) with and without induced acute inflammation. Our results showed that due to enhanced vascular permeability, magnetoliposomes accumulated at the site of inflammation in the absence of an external magnetic field, but the amount of iron present increased under the effect of a magnet located at the inflammation zone. This increase was dependent on the time (20 or 60 min) of exposure of the external magnetic field. It was also observed that the presence of the magnet was associated with lower amounts of iron in the liver, spleen, and plasma than was found in mice in which a magnet had not been applied. The results of this study confirm that it is possible to target drugs encapsulated in magnetic particles by means of an external magnet.

Ultrasound-induced cavitation damage to external epithelia of fish skin.

PubMed

Frenkel, V; Kimmel, E; Iger, Y

1999-10-01

Transmission electron microscopy was used to show the effects of therapeutic ultrasound (< or = 1.0 W/cm2, 1 MHz) on the external epithelia of fish skin. Exposures of up to 90 s produced damage to 5 to 6 of the outermost layers. Negligible temperature elevations and lack of damage observed when using degassed water indicated that the effects were due to cavitation. The minimal intensity was determined for inducing cellular damage, where the extent and depth of damage to the tissues was correlated to the exposure duration. The results may be interpreted as a damage front, advancing slowly from the outer cells inward, presumably in association with the slow replacement of the perforated cell contents with the surrounding water. This study illustrates that a controlled level of microdamage may be induced to the outer layers of the tissues.

Measurements and evaluation of the risks due to external radiation exposures and to intake of activated elements for operational staff engaged in the maintenance of medical cyclotrons.

PubMed

Calandrino, R; del Vecchio, A; Parisi, R; Todde, S; De Felice, P; Savi, A; Pepe, A; Mrskova, A

2010-06-01

The aim of this paper is to assess the activation phenomena and to evaluate the risk of external exposure and intake doses for the maintenance staff of two medical cyclotrons. Two self-shielded cyclotrons are currently operating in the facility for the routine production of (11)C and (18)F. Four radiochemistry laboratories are linked to the cyclotrons by means of shielded radioisotope delivery lines. Radiopharmaceuticals are prepared both for the PET Diagnostic Department, where four CT-PET scanners are operating with a mean patient workload of 40 d(-1) and for [(18)F]FDG external distribution, to provide radiopharmaceuticals for other institutions. In spite of the fact that air contamination inside the radiochemistry laboratories during the synthesis represents the largest 'slice of the pie' in the evaluation of annual intake dose, potential contamination due to the activated particulate, generated during cyclotron irradiation by micro-corrosion of targets and other components potentially struck by the proton beam and generated neutrons, should be considered. In this regard, the most plausible long-lived (T(1/2) > 30 d) radioisotopes formed are: (97)Tc, (56)Co, (57)Co, (58)Co, (60)Co, (49)V, (55)Fe, (109)Cd, (65)Zn and (22)Na. The results for the operating personnel survey has revealed only low-level contamination for (65)Zn in one test, together with minor (18)F intake, probably due to the environmental dispersion of the radioisotope during the [(18)F]FDG synthesis.

Estimated Internal and External Radiation Exposure of Caregivers of Patients With Pediatric Neuroblastoma Undergoing 131I Metaiodobenzylguanidine Therapy: A Prospective Pilot Study.

PubMed

Han, Sangwon; Yoo, Seon Hee; Koh, Kyung-Nam; Lee, Jong Jin

2017-04-01

Current recommendations suggest that family members should participate in the care of children receiving in-hospital I metaiodobenzylguanidine (MIBG) therapy for neuroblastoma. The present study aimed to measure the external radiation exposure and estimate the internal radiation exposure of caregivers during the hospital stay for I MIBG therapy. Caregivers received radiation safety instructions and a potassium iodide solution for thyroid blockade before patient admission. External radiation exposure was determined using a personal pocket dosimeter. Serial 24-hour urine samples were collected from caregivers during the hospital stay. Estimated internal radiation exposure was calculated based on the urine activity. Twelve cases (mean age, 6.2 ± 3.5 years; range, 2-13 years) were enrolled. The mean administered activity was 233.3 ± 74.9 (range, 150.0-350.0) mCi. The mean external radiation dose was 5.8 ± 7.2 (range, 0.8-19.9) mSv. Caregivers of children older than 4 years had significantly less external radiation exposure than those of children younger than 4 years (1.9 ± 1.0 vs 16.4 ± 5.0 mSv; P = 0.012). The mean estimated internal radiation dose was 11.3 ± 10.2 (range, 1.0-29.8) μSv. Caregivers receive both external and internal radiation exposure while providing in-hospital care to children receiving I MIBG therapy for neuroblastoma. However, the internal radiation exposure was negligible compared with the external radiation exposure.

External occupational exposures in some NORM industries located at the South-West of Spain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolivar, J. P.; Garcia-Tenorio, R.

2008-08-07

Detailed mappings of the external exposures which can be received by the workers in two NORM industrial factories located at the South-West of Spain have been performed: one devoted to the production of phosphoric acid, and the other devoted to the production of titanium dioxide pigments. In most places of the analyzed factories, the external exposures are moderated, although in some specific points, and associated to the presence of scales, their values are clearly higher. Nevertheless, under normal running conditions, the contribution of the external exposures to the effective doses received by the workers is lower than 1 mSv/y becausemore » the worker occupancy factors values are very low in the places with the highest external exposures.« less

Evaluation of external exposures of the population of Ozyorsk, Russia, with luminescence measurements of bricks.

PubMed

Woda, Clemens; Jacob, P; Ulanovsky, A; Fiedler, I; Mokrov, Y; Rovny, S

2009-11-01

Recently discovered historical documents indicate that large releases of noble gases (mainly (41)Ar and radioactive isotopes of Kr and Xe) from the Mayak Production Association (MPA) over the period from 1948 to 1956 may have caused considerable external exposures of both, inhabitants of Ozyorsk and former inhabitants of villages at the upper Techa River. To quantify this exposure, seven brick samples from three buildings in Ozyorsk, located 8-10 km north-northwest from the radioactive gas release points, were taken. The absorbed dose in brick was measured in a depth interval of 3-13 mm below the exposed surface of the bricks by means of the thermoluminescence (TL) and the optically stimulated luminescence (OSL) method. Generally, luminescence properties using TL were more favorable for precise dose determination than using OSL, but within their uncertainties the results from both methods agree well with each other. The absorbed dose due to natural radiation was assessed and subtracted under the assumption of the bricks to be completely dry. The weighted average of the anthropogenic dose for all samples measured by TL and OSL is 10 +/- 9 and 1 +/- 9 mGy, respectively. An upper limit for a possible anthropogenic dose in brick that would not be detected due to the measurement uncertainties is estimated at 24 mGy. This corresponds to an effective dose of about 21 mSv. A similar range of values is obtained in recently published dispersion calculations that were based on reconstructed MPA releases. It is concluded that the release of radioactive noble gases from the radiochemical and reactor plants at Mayak PA did not lead to a significant external exposure of the population of Ozyorsk. In addition, the study demonstrates the detection limit for anthropogenic doses in ca. 60-year-old bricks to be about 24 mGy, if luminescence methods are used.

Engaging with local stakeholders: some lessons from Fukushima for recovery.

PubMed

Hayano, R S

2015-06-01

The Fukushima Daiichi nuclear power plant accident contaminated the soil of densely populated regions in Fukushima prefecture with radioactive caesium, which poses significant risks of internal and external exposure to the residents. Applying the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv per year would be expected to be common in Fukushima. However, extensive whole-body-counter surveys have shown that the internal exposure levels of residents are much lower than estimated; in 2012-2013, the Cs-137 detection percentages (the detection limit being ∼300 Bq body(-1)) were approximately 1% for adults and practically 0% for children. These results are consistent with those of many other measurements/studies conducted to date in Fukushima. As a consequence, risks from external exposure assume greater importance for the majority of residents in Fukushima due to the lower contribution from internal exposure. In both cases, average doses remain low, although some residents are exposed to higher-than-average risks; it is these members of the population who need to be identified and followed-up. Consequently, it is essential to re-establish communication at all levels in society. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Radiation doses to critical groups since the early 1950s due to discharges of liquid radioactive waste from Sellafield.

PubMed

Hunt, G J

1997-04-01

First, some of the early work is reviewed on exposure pathways in connection with proposed and early liquid radioactive waste discharges from Sellafield. The main historical features of these discharges, affected by relevant plant operations, are then briefly described. The important radiological exposure pathways resulting from the discharges and people's consumption and occupancy habits are considered. To place the changing scenario onto a consistent basis using present-day methodology, a reconstruction of exposures has been carried out using environmental monitoring data and models. The three major pathways are examined of Porphyra/laverbread consumption in South Wales, fish and shellfish consumption near Sellafield, and external exposure over local and more distant sediments. The results show that over the period 1952 to about 1970 the laverbread pathway was probably critical, taking a cautious approach. Effective dose rates fluctuated at around 1 mSv y(-1) from about 1956 to 1971. From about 1970 to 1985, the fish and shellfish pathway was likely to have been critical, with effective dose rates peaking at about 2 mSv y(-1) in 1975-1976. External exposure was likely to have been of lesser importance than the other two pathways until about 1985, when with the retention of previously-released radiocesium on sediments it has become dominant. This phenomenon applies particularly further afield where radiocesium concentrations have been slower to decline; in the Ribble estuary, houseboat dwellers have been the critical group from about 1985. Effective doses have been at about 0.3 mSv y(-1) and declining; they are due to the effects of radiocesium discharges in earlier years. Dose rates have remained within contemporary ICRP dose limits.

Years of life lost and morbidity cases attributable to transportation noise and air pollution: A comparative health risk assessment for Switzerland in 2010.

PubMed

Vienneau, Danielle; Perez, Laura; Schindler, Christian; Lieb, Christoph; Sommer, Heini; Probst-Hensch, Nicole; Künzli, Nino; Röösli, Martin

2015-08-01

There is growing evidence that chronic exposure to transportation related noise and air pollution affects human health. However, health burden to a country of these two pollutants have been rarely compared. As an input for external cost quantification, we estimated the cardiorespiratory health burden from transportation related noise and air pollution in Switzerland, incorporating the most recent findings related to the health effects of noise. Spatially resolved noise and air pollution models for the year 2010 were derived for road, rail and aircraft sources. Average day-evening-night sound level (Lden) and particulate matter (PM10) were selected as indicators, and population-weighted exposures derived by transportation source. Cause-specific exposure-response functions were derived from a meta-analysis for noise and literature review for PM10. Years of life lost (YLL) were calculated using life table methods; population attributable fraction was used for deriving attributable cases for hospitalisations, respiratory illnesses, visits to general practitioners and restricted activity days. The mean population weighted exposure above a threshold of 48dB(A) was 8.74dB(A), 1.89dB(A) and 0.37dB(A) for road, rail and aircraft noise. Corresponding mean exposure contributions were 4.4, 0.54, 0.12μg/m(3) for PM10. We estimated that in 2010 in Switzerland transportation caused 6000 and 14,000 YLL from noise and air pollution exposure, respectively. While there were a total of 8700 cardiorespiratory hospital days attributed to air pollution exposure, estimated burden due to noise alone amounted to 22,500 hospital days. YLL due to transportation related pollution in Switzerland is dominated by air pollution from road traffic, whereas consequences for morbidity and indicators of quality of life are dominated by noise. In terms of total external costs the burden of noise equals that of air pollution. Copyright © 2015 Elsevier GmbH. All rights reserved.

AN ESTIMATION OF THE EXPOSURE OF THE POPULATION OF ISRAEL TO NATURAL SOURCES OF IONIZING RADIATION.

PubMed

Epstein, L; Koch, J; Riemer, T; Haquin, G; Orion, I

2017-11-01

The radiation dose to the population of Israel due to exposure to natural sources of ionizing radiation was assessed. The main contributor to the dose is radon that accounts for 60% of the exposure to natural sources. The dose due to radon inhalation was assessed by combining the results of a radon survey in single-family houses with the results of a survey in apartments in multi-storey buildings. The average annual dose due to radon inhalation was found to be 1.2 mSv. The dose rate due to exposure to cosmic radiation was assessed using a code that calculates the dose rate at different heights above sea level, taking into account the solar cycle. The annual dose was calculated based on the fraction of time spent indoors and the attenuation provided by buildings and was found to be 0.2 mSv. The annual dose due to external exposure to the terrestrial radionuclides was similarly assessed. The indoor dose rate was calculated using a model that takes into account the concentrations of the natural radionuclides in building materials, the density and the thickness of the walls. The dose rate outdoors was calculated based on the concentrations of the natural radionuclides in different geological units in Israel as measured in an aerial survey and measurements above ground. The annual dose was found to be 0.2 mSv. Doses due to internal exposure other than exposure to radon were also calculated and were found to be 0.4 mSv. The overall annual exposure of the population of Israel to natural sources of ionizing radiation is therefore 2 mSv and ranges between 1.7 and 2.7 mSv. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

An Exploratory Study: Assessment of Modeled Dioxin Exposure in Ceramic Art Studios (External Review Draft)

EPA Science Inventory

EPA has released an external review draft entitled, An Exploratory Study: Assessment of Modeled Dioxin Exposure in Ceramic Art Studios(External Review Draft). The public comment period and the external peer-review workshop are separate processes that provide opportunities ...

Human response to vibration in residential environments.

PubMed

Waddington, David C; Woodcock, James; Peris, Eulalia; Condie, Jenna; Sica, Gennaro; Moorhouse, Andrew T; Steele, Andy

2014-01-01

This paper presents the main findings of a field survey conducted in the United Kingdom into the human response to vibration in residential environments. The main aim of this study was to derive exposure-response relationships for annoyance due to vibration from environmental sources. The sources of vibration considered in this paper are railway and construction activity. Annoyance data were collected using questionnaires conducted face-to-face with residents in their own homes. Questionnaires were completed with residents exposed to railway induced vibration (N = 931) and vibration from the construction of a light rail system (N = 350). Measurements of vibration were conducted at internal and external positions from which estimates of 24-h vibration exposure were derived for 1073 of the case studies. Sixty different vibration exposure descriptors along with 6 different frequency weightings were assessed as potential predictors of annoyance. Of the exposure descriptors considered, none were found to be a better predictor of annoyance than any other. However, use of relevant frequency weightings was found to improve correlation between vibration exposure and annoyance. A unified exposure-response relationship could not be derived due to differences in response to the two sources so separate relationships are presented for each source.

Real time chemical exposure and risk monitor

DOEpatents

Thrall, Karla D.; Kenny, Donald V.; Endres, George W. R.; Sisk, Daniel R.

1997-01-01

The apparatus of the present invention is a combination of a breath interface and an external exposure dosimeter interface to a chemical analysis device, all controlled by an electronic processor for quantitatively analyzing chemical analysis data from both the breath interface and the external exposure dosimeter for determining internal tissue dose. The method of the present invention is a combination of steps of measuring an external dose, measuring breath content, then analyzing the external dose and breath content and determining internal tissue dose.

Real time chemical exposure and risk monitor

DOEpatents

Thrall, K.D.; Kenny, D.V.; Endres, G.W.R.; Sisk, D.R.

1997-07-08

The apparatus of the present invention is a combination of a breath interface and an external exposure dosimeter interface to a chemical analysis device, all controlled by an electronic processor for quantitatively analyzing chemical analysis data from both the breath interface and the external exposure dosimeter for determining internal tissue dose. The method of the present invention is a combination of steps of measuring an external dose, measuring breath content, then analyzing the external dose and breath content and determining internal tissue dose. 7 figs.

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

PubMed Central

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. PMID:22719759

Occupational exposures in two industrial plants devoted to the production of ammonium phosphate fertilisers.

PubMed

Bolívar, J P; García-Tenorio, R; Mosqueda, F; Gázquez, M J; López-Coto, I; Adame, J A; Vaca, F

2013-03-01

In order to fill a gap in the open literature, occupational exposures and activity concentrations have been assessed in two NORM industrial plants, located in the south-west of Spain, devoted to the production of mono-ammonium phosphate (MAP) and di-ammonium phosphate (DAP) fertilisers. The annual effective doses received by the workers from these plants are clearly below 1 mSv yr(-1) and the contribution due to external radiation is similar to that due to inhalation. The contribution to the maximum effective doses due to inhalation of particulate matter has been estimated to be about 0.12 mSv yr(-1), while the (222)Rn concentrations inside the plants are of no concern. Consequently, no additional actions or radiological protection measures need to be taken to decrease the natural radiation received by the workers in these facilities.

Role of Direct and Indirect Violence Exposure on Externalizing Behavior in Children.

PubMed

Fleckman, Julia M; Drury, Stacy S; Taylor, Catherine A; Theall, Katherine P

2016-06-01

The objective of this study was to examine the association between externalizing behaviors and indirect violence exposure, assessed both within the household and at the community level, as well as the interaction effect of indirect and direct violence exposure. A sample of parents of children ages 4-15 who have not been referred or enrolled in child welfare (n = 82) were recruited from the greater New Orleans community. Externalizing behavior was assessed with the Child Behavior Checklist (CBCL). The child's indirect exposure to violence included witnessing community violence, witnessing physical assault, and witnessing fighting or domestic violence at home. Direct exposure to violence included the child experiencing physical aggression from a caregiver. All assessments were based on caregiver reports. To decrease potential for confounding, children were matched for analysis based on age, Hurricane Katrina exposure, and their propensity to be exposed to high indirect violence. Cumulative indirect exposure to violence was significantly positively correlated with CBCL scores. After controlling for key covariates, CBCL externalizing T score increased significantly by approximately 1.25 points for each level increase in indirect violence exposure (β = 1.25, SE = 0.57, p = 0.027). There also was a significant interaction between indirect and direct exposure to violence in the association with CBCL score (β = -0.08, SE = 0.03, p = 0.002). These findings extend previous research by demonstrating that exposure to both direct and cross-contextual indirect violence influences externalizing behaviors in children. Additionally, the findings suggest that community and household social environments are both important targets for interventions designed to decrease externalizing behaviors and improve long-term outcomes for youth at risk of exposure to violence.

External exposure doses due to gamma emitting natural radionuclides in some Egyptian building materials.

PubMed

Moharram, B M; Suliman, M N; Zahran, N F; Shennawy, S E; El Sayed, A R

2012-01-01

Using of building materials containing naturally occurring radionuclides as (238)U, (232)Th and (40)K and their progeny results in an external exposures of the housing of such buildings. In the present study, indoor dose rates for typical Egyptian rooms are calculated using the analytical method and activity concentrations of natural radionuclides in some building materials. Uniform chemical composition of the walls, floor and ceiling as well as uniform mass concentrations of the radionuclides in walls, floor and ceiling assumed. Different room models are assumed to discuss variation of indoor dose rates according to variation in room construction. Activity concentrations of (238)U, (232)Th and (40)K content in eight samples representative Clay soil and different building materials used in most recent Egyptian building were measured using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The specific activity for (238)U, (232)Th and (40)K, from the selected samples, were in the range 14.15-60.64, 2.75-84.66 and 7.35-554.4Bqkg(-1), respectively. The average indoor absorbed dose rates in air ranged from 0.005μGyh(-1) to 0.071μGyh(-1) and the corresponding population-weighted annual effective dose due to external gamma radiation varies from 0.025 to 0.345mSv. An outdoor dose rate for typical building samples in addition to some radiological hazards has been introduced for comparison. Copyright © 2011 Elsevier Ltd. All rights reserved.

Family Resources as Protective Factors for Low-Income Youth Exposed to Community Violence.

PubMed

Hardaway, Cecily R; Sterrett-Hong, Emma; Larkby, Cynthia A; Cornelius, Marie D

2016-07-01

Exposure to community violence is a risk factor for internalizing and externalizing problems; however, resources within the family can decrease the likelihood that adolescents will experience internalizing and externalizing problems as a result of such exposure. This study investigates the potential moderating effects of kinship support (i.e., emotional and tangible support from extended family) and parental involvement on the relation between exposure to community violence (i.e., witnessing violence and violent victimization) and socioemotional adjustment (i.e., internalizing and externalizing problems) in low-income adolescents. The sample included 312 (50 % female; 71 % African American and 29 % White) low-income youth who participated in a longitudinal investigation when adolescents were age 14 (M age = 14.49 years) and again when they were 16 (M age = 16.49 years). Exposure to community violence at age 14 was related to more internalizing and externalizing problems at age 16. High levels of kinship support and parental involvement appeared to function as protective factors, weakening the association between exposure to violence and externalizing problems. Contrary to prediction, none of the hypothesized protective factors moderated the association between exposure to violence and internalizing problems. The results from this study suggest that both kinship support and parental involvement help buffer adolescents from externalizing problems that are associated with exposure to community violence.

The Semipalatinsk nuclear test site: a first assessment of the radiological situation and the test-related radiation doses in the surrounding territories.

PubMed

Gusev, B I; Abylkassimova, Z N; Apsalikov, K N

1997-09-01

As a result of atmospheric nuclear tests at the Semipalatinsk test site 'Polygon', adjacent territories were contaminated by radionuclide fallout. The population of some districts in the Semipalatinsk oblast were exposed to elevated levels of radiation. Contamination and exposure mostly resulted from early atmospheric tests. The radiological situation of the Semipalatinsk oblast is described. Effective dose estimates due to external and internal exposure attributable to the 1949 and 1953 tests in villages near the Polygon range from 70 mSv to 4470 mSv.

Effective gamma-ray doses due to natural radiation from soils of southeastern Brazil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silveira, M. A. G.; Moreira, R. H.; Bellini, B. S.

2010-08-04

We have used gamma-ray spectrometry to study the distribution of natural radiation from soils of southeastern Brazil: Billings reservoir, Sao Bernardo do Campo Parks, Diadema Parks, Interlagos region, Sao Paulo, and soil from Sao Paulo and Rio de Janeiro beaches. In most of the regions studied we have found that the dose due the external exposure to gamma-rays, proceeding from natural terrestrial elements, are between the values 0.3 and 0.6 mSv/year, established by the United Nations Scientific Committee on the Effects of Atomic Radiation.

The Study of Natural Radiation Distribution in Soil of Sao Bernardo do Campo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsumoto, M. M.; Silveira, M. A. G.; Medina, N. H.

2008-08-07

We have studied the distribution of natural radioactivity in the soil of five sites of the city Sao Bernardo do Campo, Sao Paulo, Brazil. The main contribution of the radiation dose is due to the isotope {sup 40}K, with smaller contributions from the elements of the series of {sup 238}U and {sup 232}Th. The results indicate the dose in all of the studied areas is around the average international dose due to external exposure to gamma rays (0.48 mSv/yr) proceeding from natural terrestrial elements.

Life-threatening hemolytic anemia due to an autoanti-Pr cold agglutinin: evidence that glycophorin A antibodies may induce lipid bilayer exposure and cation permeability independent of agglutination.

PubMed

Brain, Michael C; Ruether, Bernard; Valentine, Karen; Brown, Christopher; ter Keurs, Henk

2010-02-01

The hemoglobin of a 29-year-old man fell below 35 g/L over 5 days, despite 14 units of red blood cells (RBCs), due to an anti-Pr cold agglutinin (CA). His hemolytic anemia necessitated respiratory support in intensive care for 4 weeks. The hemolysis was investigated by the effects on blood group-compatible RBCs of this anti-Pr and an anti-I CA and of a rabbit anti-human glycophorin A (GPA) immunoglobulin G (IgG) antibody on Ca(2+) permeability and of phosphatidylethanolamine (PE) exposure. 1) The anti-Pr CA (in a plasmapheresis product from the patient) was absorbed and eluted from RBC ghosts and its immunophenotype was determined by agarose electrophoresis and immunofixation. 2) Ca(2+) permeability was measured by the response of Fluo-3-labeled RBCs to addition of external Ca(2+). 3) Exposed PE was measured with streptavidin-labeled biotinylated peptide Ro 09-0198 (cinnamycin). 1) The patient's anti-Pr CA was a polyclonal IgG. 2) The anti-Pr and the rabbit anti-human glycophorin IgG, but not an anti-I CA, rapidly increased Ca(2+)-dependent fluorescence upon addition of external Ca(2+) in a fraction (15%-25%) of RBCs that also became positive for cinnamycin. 3) Trypsin treatment of RBCs reduced the Ca(2+) influx due to the anti-Pr IgG, but neither trypsin nor neuraminidase changed the responses to the rabbit anti-human GPA IgG. The anti-Pr CA and rabbit anti-human GPA increased exposure of PE and increased membrane Ca(2+) permeability that may have caused hemolysis. The difference in the responses to these antibodies to enzyme treatment of RBCs suggests that they react with different epitopes on GPA.

External validation of the bilirubin-atazanavir nomogram for assessment of atazanavir plasma exposure in HIV-1-infected patients.

PubMed

Rekić, Dinko; Röshammar, Daniel; Bergstrand, Martin; Tarning, Joel; Calcagno, Andrea; D'Avolio, Antonio; Ormaasen, Vidar; Vigan, Marie; Barrail-Tran, Aurélie; Ashton, Michael; Gisslén, Magnus; Äbelö, Angela

2013-04-01

Atazanavir increases plasma bilirubin levels in a concentration-dependent manner. Due to less costly and readily available assays, bilirubin has been proposed as a marker of atazanavir exposure. In this work, a previously developed nomogram for detection of suboptimal atazanavir exposure is validated against external patient populations. The bilirubin nomogram was validated against 311 matching bilirubin and atazanavir samples from 166 HIV-1-infected Norwegian, French, and Italian patients on a ritonavir-boosted regimen. In addition, the nomogram was evaluated in 56 Italian patients on an unboosted regimen. The predictive properties of the nomogram were validated against observed atazanavir plasma concentrations. The use of the nomogram to detect non-adherence was also investigated by simulation. The bilirubin nomogram predicted suboptimal exposure in the patient populations on a ritonavir-boosted regimen with a negative predictive value of 97% (95% CI 95-100). The bilirubin nomogram and monitoring of atazanavir concentrations had similar predictive properties for detecting non-adherence based on simulations. Although both methods performed adequately during a period of non-adherence, they had lower predictive power to detect past non-adherence episodes. Using the bilirubin nomogram for detection of suboptimal atazanavir exposure in patients on a ritonavir-boosted regimen is a rapid and cost-effective alternative to routine measurements of the actual atazanavir exposure in plasma. Its application may be useful in clinical settings if atazanavir concentrations are not available.

Effects of aqueous humor hydrodynamics on human eye heat transfer under external heat sources.

PubMed

Tiang, Kor L; Ooi, Ean H

2016-08-01

The majority of the eye models developed in the late 90s and early 00s considers only heat conduction inside the eye. This assumption is not entirely correct, since the anterior and posterior chambers are filled aqueous humor (AH) that is constantly in motion due to thermally-induced buoyancy. In this paper, a three-dimensional model of the human eye is developed to investigate the effects AH hydrodynamics have on the human eye temperature under exposure to external heat sources. If the effects of AH flow are negligible, then future models can be developed without taking them into account, thus simplifying the modeling process. Two types of external thermal loads are considered; volumetric and surface irradiation. Results showed that heat convection due to AH flow contributes to nearly 95% of the total heat flow inside the anterior chamber. Moreover, the circulation inside the anterior chamber can cause an upward shift of the location of hotspot. This can have significant consequences to our understanding of heat-induced cataractogenesis. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

beta- and gamma-Comparative dose estimates on Enewetak Atoll.

PubMed

Crase, K W; Gudiksen, P H; Robison, W L

1982-05-01

Enewetak Atoll is one of the Pacific atolls used for atmospheric testing of U.S. nuclear weapons. Beta dose and gamma-ray exposure measurements were made on two islands of the Enewetak Atoll during July-August 1976 to determine the beta and low energy gamma-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a beta-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to beta- or low energy gamma-contribution. The contribution at any particular site, however, is somewhat dependent on ground cover, since a minimal amount of vegetation will reduce it significantly from that over bare soil, but thick stands of vegetation have little effect on any further reductions. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey (En73). Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the beta's or low energy gamma's, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

Long-term health experience of jet engine manufacturing workers: VI: incidence of malignant central nervous system neoplasms in relation to estimated workplace exposures.

PubMed

Marsh, Gary M; Youk, Ada O; Buchanich, Jeanine M; Xu, Hui; Downing, Sarah; Kennedy, Kathleen J; Esmen, Nurtan A; Hancock, Roger P; Lacey, Steven E; Fleissner, Mary Lou

2013-06-01

To determine whether glioblastoma (GB) incidence rates among jet engine manufacturing workers were associated with specific chemical or physical exposures. Subjects were 210,784 workers employed from 1952 to 2001. We conducted a cohort incidence study and two nested case-control studies with focus on the North Haven facility where we previously observed a not statistically significant overall elevation in GB rates. We estimated individual-level exposure metrics for 11 agents. In the total cohort, none of the agent metrics considered was associated with increased GB risk. The GB incidence rates in North Haven were also not related to workplace exposures, including the "blue haze" exposure unique to North Haven. If not due to chance alone, GB rates in North Haven may reflect external occupational factors, nonoccupational factors, or workplace factors unique to North Haven unmeasured in the current evaluation.

FEASIBILITY STUDY FOR IDENTIFICATION OF STATIC AND DYNAMIC EXPOSURE USING CCD IMAGING TECHNIQUE FOR Caso4:Dy TL DOSEMETERS.

PubMed

Srivastava, Kshama; Soin, Seepika; Sapra, B K; Ratna, P; Datta, D

2017-11-01

The occupational exposure incurred by the radiation workers due to the external radiation is estimated using personal dosemeter placed on the human body during the monitoring period. In certain situations, it is required to determine whether the dosemeter alone was exposed accidentally/intentionally in radiation field (static exposure) or was exposed while being worn by a worker moving in his workplace (dynamic exposure). The present thermoluminscent (TL) based personnel monitoring systems are not capable of distinguishing between the above stated (static and dynamic) exposure conditions. The feasibility of a new methodology developed using the charge coupled device based imaging technique for identification of the static/dynamic exposure of CaSO4:Dy based TL detectors for low energy photons has been investigated. The techniques for the qualitative and the quantitative assessments of the exposure conditions are presented in this paper. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Current and historical individual data about exposure of workers in the rayon industry to carbon disulfide and their validity in calculating the cumulative dose.

PubMed

Göen, Thomas; Schramm, Axel; Baumeister, Thomas; Uter, Wolfgang; Drexler, Hans

2014-08-01

The objective of the study was to investigate how exposure to carbon disulfide (CS2) in a rayon-manufacturing plant has changed within two decades and whether it is possible to calculate valid data for the individual cumulative exposure. The data for CS2 concentration in air and biological exposure monitoring (2-thio-1,3-thiaxolidine-4-carboxylic acid (TTCA) in urine) from two cross-sectional studies, performed in 1992 (n = 362) and 2009 (n = 212) in a German rayon-manufacturing plant, were compared to data obtained from company-internal measurements between the studies. Using the data from the cross-sectional studies and company-internal data, cumulative external exposure and the cumulative internal exposure were calculated for each worker. External and internal CS2 exposure of the employees decreased from 1992 (medians 4.0 ppm and 1.63 mgTTCA/g creatinine) to 2009 (medians 2.5 ppm and 0.86 mg/g). However, company-internal CS2 data do not show a straight trend for this period. The annual medians of the company-internal measurement of external exposure to CS2 have varied between 2.7 and 8.4 ppm, in which median values exceeded 5 ppm generally since 2000. The annual medians for the company-internal biomonitoring assessment ranged between 1.2 and 2.8 mg/g creatinine. The cumulative CS2 exposure ranged from 8.5 to 869.5 ppm years for external exposure and between 1.30 and 176.2 mg/g creatinine years for the internal exposure. Significant correlations were found between the current air pollution and the internal exposure in 2009 but also between the cumulative external and internal CS2 exposure. Current exposure data, usually collected in cross-sectional studies, rarely allow a reliable statement on the cumulative dose, because of higher exposure in the past and of fluctuating courses of exposure. On the other hand, company-internal exposure data may be affected by non-representative measurement strategies. Some verification of the reliability of cumulative exposure data may be possible by testing the correlation between cumulative exposure data of external assessment and biological monitoring.

Public exposure due to external gamma background radiation in boundary areas of Iran.

PubMed

Pooya, S M Hosseini; Dashtipour, M R; Enferadi, A; Orouji, T

2015-09-01

A monitoring program in boundary areas of a country is an appropriate way to indicate the level of public exposure. In this research, gamma background radiation was measured using TL dosimeters at 12 boundary areas as well as in the capital city of Iran during the period 2010 to 2011. The measurements were carried out in semi-annual time intervals from January to June and July to December in each year. The maximum average dose equivalent value measured was approximately 70 μSv/month for Tehran city. Also, the average dose values obtained were less than 40 μSv/month for all the cities located at the sea level except that of high level natural radiation area of Ramsar, and more than 55 μSv/month for the higher elevation cities. The public exposure due to ambient gamma dose equivalent in Iran is within the levels reported by UNSCEAR. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ambient Dose Equivalent in S. Paulo and Bauru cities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umisedo, Nancy K.; Okuno, Emico; Cancio, Francisco S.

2008-08-07

The Laboratory of Dosimetry (Institute of Physics, University of S. Paulo) performs since 1981 the external individual monitoring of workers exposed to X and gamma rays based on thermoluminescent dosimetry (TLD). Personal dose equivalent refers only to the exposure of workers due to the working activities, and the dose due to background radiation, also measured with TLD, must be subtracted to evaluate it. A compilation of ambient dose equivalent was done to evaluate the dose due to the background radiation in the work places, and also to contribute to the knowledge of the level of indoor radiation to which themore » public is exposed.« less

Cancer deaths and occupational exposure in a group of plutonium workers.

PubMed

Fallahian, Naz Afarin; Brey, Richard R; Tivis, Rick D; Piland, Neill F; Simpson, David R

2012-04-01

An exploratory epidemiological study was conducted for 319 deceased nuclear workers who had intakes of transuranic radionuclides and histories of employment during the time period from 1943 to 1995. The workers were employed at various facilities throughout the United States, including the Department of Energy defense facilities and uranium mining and milling sites. The majority of individuals were involved in documented radiological incidents during their careers. All had voluntarily agreed to donate their organs or whole body to the United States Transuranium and Uranium Registries. External and internal dose assessments were performed using occupational exposure histories and postmortem concentrations of transuranic radionuclides in critical organs. Statistical data analyses were performed to investigate the potential relationship between radiation exposure and causes of death within this population due to cancers of the lungs, liver, and all sites combined while controlling for the effects of other confounders. No association was found between radiation exposure and death due to cancer (α = 0.05). However, statistically significant associations were found between death due to any type of cancer and smoking (yes or no) (odds ratio = 5.41; 95% CI: 1.42 to 20.67) and rate of cigarette smoking (packs per day) (odds ratio = 2.70; 95% CI: 1.37 to 5.30).

Esophagus cancer and radiation exposure due to nuclear test fallout: an analysis based on the data of the Semipalatinsk historical cohort, 1960-1999.

PubMed

Bauer, S; Gusev, B I; Pivina, L M; Apsalikov, K N; Grosche, B

2006-01-01

This paper describes the Semipalatinsk historical cohort study and, in particular, examines the association between combined external and internal radiation exposure and esophagus cancer. Esophagus cancer is the most frequent single cancer site in the cause of death follow-up for the Semipalatinsk cohort. Set up in the 1960s, this historical cohort included 10 exposed settlements in the vicinity of the Semipalatinsk nuclear test site in East Kazakhstan as well as 6 comparison settlements in a low exposure area of the same region. The external and internal radiation doses to the population of the settlements under study were mainly due to local fallout from atmospheric nuclear testing (1949-1962). The database includes dosimetry and health information for 19.545 inhabitants of exposed and comparison villages in the Semipalatinsk region, comprising a total of 582.750 person-years of follow-up between 1960 and 1999. Cumulative effective dose estimates in this cohort range from 20 mSv to -4 Sv, with a mean dose of 634 mSv in the exposed group. Relative risks were calculated in terms of rate ratios, using a Poisson regression model for grouped person-time data. Esophagus cancer was found substantially elevated, with a statistically significant increase of the relative risk with dose and an ERR/Sv of 2.37 (1.45; 3.28) for the total cohort. If the data set was restricted to the exposed group only, the ERR/Sv was found considerably lower (0.18 (-0.16; 0.52)), whereas the dose-response remained significant only in women. Overall, our results based on the Semipalatinsk historical cohort indicate an association between fallout exposure and the risk of esophagus cancer that should be further investigated.

Development of external and neutrally buoyant acoustic transmitters for turbine passage evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Zhiqun; Brown, Richard S.; Carlson, Thomas J.

Recent studies show transmitters surgically implanted into juvenile salmonids, for the purposes of estimating survival of fish passing through turbines, increases the risk of injury and mortality due to the presence of the tag and exposure to rapid turbine pressure changes. Neutrally buoyant external tags may instead be used to eliminate this bias. However, the externally tagged fish could be affected by other factors such as shear and turbulence which may also bias survival estimates. Studies have been conducted to examine the influence of shear and turbulence on non-tagged juvenile salmonids, however, tests have never been conducted in the laboratorymore » or field to determine the influence of shear and turbulence on retention and injury related to attachment of external transmitters. We designed and manufactured two different configurations of neutrally buoyant (nearly zero g weight in water) external transmitters: Type A and Type B. The Type A transmitters weigh approximately 0.60 g in air and are attached to fish using two sutures anterior to the dorsal fin. The Type B transmitters weigh approximately 0.83 g in air and consist of battery part and transducer part with both parts neutrally buoyant. They are attached to both sides of the dorsal fin using two enamel coated 25 gauge magnet wires. This study provides a broad approach using evaluation measures such as holding, swimming performance, shear, turbulence, rapid decompression exposures, and predation to determine the efficacy of using neutrally buoyant external transmitters to estimate survival of juvenile salmonids passing through turbines. Preliminary results show the Type A design is a viable design for turbine passage evaluation and is being planned for field deployment in the near future.« less

Patterns of poverty exposure and children's trajectories of externalizing and internalizing behaviors.

PubMed

Comeau, Jinette; Boyle, Michael H

2018-04-01

Using data from the Child Supplement of the National Longitudinal Survey of Youth, we compare trajectories of externalizing and internalizing behaviors among children exposed to five patterns of poverty from birth to age 14: always or never poor - stable patterns; a single transition into or out of poverty, or repeated fluctuations in and out of poverty - changing patterns. We also examine how low maternal education and single parenthood interact with these poverty exposures to compound their adverse effects. Finally, we compare the magnitude of effects associated with the patterns of poverty exposure, as well as their interactions with low maternal education and single parenthood, on trajectories of externalizing and internalizing behaviors to determine if they are significantly different. Results reveal that initial levels and rates of change in children's trajectories of externalizing and internalizing behaviors are similar across the three changing patterns of poverty exposure, leading us to combine them into a single group representing intermittent poverty. Initial disparities between children who are never poor and their counterparts who are always or intermittently poor are constant over time for internalizing behaviors and grow in magnitude for externalizing behaviors. The cumulative negative effect of poverty exposure over time is stronger for externalizing vs. internalizing behaviors. Low maternal education compounds the adverse effects of persistent poverty, an effect that is similar for externalizing and internalizing behaviors.

ESTIMATION OF EFFECTIVE DOSE FROM EXTERNAL EXPOSURE DUE TO SHORT-LIVED NUCLIDES IN THE PREFECTURES SURROUNDING FUKUSHIMA.

PubMed

Miyatake, Hirokazu; Yoshizawa, Nobuaki; Suzuki, Gen

2018-05-11

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident resulted in a release of radionuclides into the environment. Since the accident, measurements of radiation in the environment such as air dose rate and deposition density of radionuclides have been performed by various organizations and universities. In particular, Japan Atomic Energy Agency (JAEA) has been performing observations of air dose rate using a car-borne survey system continuously over widespread areas. Based on the data measured by JAEA, we estimated effective dose from external exposure in the prefectures surrounding Fukushima. Since car-borne survey started a few months after the accident, the main contribution to measured data comes from 137Cs and 134Cs whose half-lives are relatively long. Using air dose rate of 137Cs and 134Cs and the ratio of deposition density of short-lived nuclides to that of 137Cs and 134Cs, we also estimated contributions to the effective dose from other short-lived nuclides.

Biomarkers: The Clues to Genetic Susceptibility.

PubMed Central

Zeiger, M

1994-01-01

There are approximately 500,000 cancer-related deaths annually in the United States. Scientists believe as that many as 80% of those deaths could be prevented due to the fact that most malignancies are a result of external factors rather than inherent biological conditions. With recent advances in molecular biology, a new field that combines highly sensitive and specific techniques for detecting early damage associated with cancer has emerged. By combining knowledge about external factors related to lifestyle and environmental or occupational exposure to chemicals with knowledge of how genetic differences cause variations in human responses to environmental pollutants, scientists are developing a better understanding of questions such as why some smokers get cancer but others do not, why certain groups of people have a higher incidence of cancer after exposure to a toxicant and others do not, and why certain women are more prone to develop breast cancer than others. Scientists using biomarkers of susceptibility will be able to identify risks and prevent adverse health effects through prevention and intervention strategies. PMID:9719667

Assessment of radio frequency exposures in schools, homes, and public places in Belgium.

PubMed

Verloock, Leen; Joseph, Wout; Goeminne, Francis; Martens, Luc; Verlaek, Mart; Constandt, Kim

2014-12-01

Characterization of exposure from emerging radio frequency (RF) technologies in areas where children are present is important. Exposure to RF electromagnetic fields (EMF) was assessed in three "sensitive" microenvironments; namely, schools, homes, and public places located in urban environments and compared to exposure in offices. In situ assessment was conducted by performing spatial broadband and accurate narrowband measurements, providing 6-min averaged electric-field strengths. A distinction between internal (transmitters that are located indoors) and external (outdoor sources from broadcasting and telecommunication) sources was made. Ninety-four percent of the broadband measurements were below 1 V m(-1). The average and maximal total electric-field values in schools, homes, and public places were 0.2 and 3.2 V m(-1) (WiFi), 0.1 and 1.1 V m(-1) (telecommunication), and 0.6 and 2.4 V m(-1) (telecommunication), respectively, while for offices, average and maximal exposure were 0.9 and 3.3 V m(-1) (telecommunication), satisfying the ICNIRP reference levels. In the schools considered, the highest maximal and average field values were due to internal signals (WiFi). In the homes, public places, and offices considered, the highest maximal and average field values originated from telecommunication signals. Lowest exposures were obtained in homes. Internal sources contributed on average more indoors (31.2%) than outdoors (2.3%), while the average contributions of external sources (broadcast and telecommunication sources) were higher outdoors (97.7%) than at indoor positions (68.8%). FM, GSM, and UMTS dominate the total downlink exposure in the outdoor measurements. In indoor measurements, FM, GSM, and WiFi dominate the total exposure. The average contribution of the emerging technology LTE was only 0.6%.

External-cause mortality among 21 609 Norwegian male military peacekeepers deployed to Lebanon between 1978 and 1998.

PubMed

Strand, Leif Aage; Martinsen, Jan Ivar; Fadum, Elin Anita; Borud, Einar Kristian

2017-08-01

To investigate external-cause mortality among 21 609 Norwegian male military peacekeepers deployed to Lebanon during 1978-1998. The cohort was followed from the 1st day of deployment through 2013, and mortality during deployment and post discharge was assessed using SMRs calculated from national rates in Norway. Poisson regression was used to see the effect of high-conflict versus low-conflict exposure. For the total cohort, external-cause mortality was within expected values during deployment (SMR=0.80) and post discharge (SMR=1.05). In the low-conflict exposure group, a lower mortality from all external causes (SMR=0.77), transport accidents (SMR=0.55) and accidental poisoning (SMR=0.53) was seen. The high-conflict exposure group showed an elevated mortality from all external causes (SMR=1.20), transport accidents (SMR=1.51) and suicide (SMR=1.30), but these risks were elevated only during the first 5 years after discharge. This group also showed elevated mortality from all external causes (rate ratio, RR=1.49), and for transport accidents (RR=3.30) when compared with the low-conflict exposure group. Overall external-cause mortality among our peacekeepers was equal to national rates during deployment and post discharge. High-conflict exposure was associated with elevated mortality from all external causes, transport accidents and suicide during the first 5 years after discharge from service. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Somatic mutation frequencies in the stamen hairs of Tradescantia grown in soil samples from the Bikini Island.

PubMed

Ichikawa, S; Ishii, C

1991-02-01

Somatic pink mutation frequencies in the stamen hairs of Tradescantia BNL 02 clone grown for 76 days in two soil samples taken from the Bikini Island (where a hydrogen bomb explosion test had been conducted in 1954) were investigated. A significantly high mutation frequency (2.58 +/- 0.17 pink mutant events per 10(3) hairs or 1.34 +/- 0.09 pink mutant events per 10(4) hair-cell divisions) was observed for the plant grown in one of the two Bikini soil samples, as compared to the control plants (1.70 +/- 0.14 or 0.88 +/- 0.07, respectively) grown in the field soil of Saitama University. The soil sample which caused the significant increase in mutation frequency contained 6,880 +/- 330 mBq/g 137Cs, 62.5 +/- 4.4 mBq/g 60Co, and some other nuclides; a 150 microR/hr exposure rate being measured on the surface of the soil sample. The effective cumulative external exposures measured for the inflorescences of the plant grown in this soil sample averaged at most 60.8 mR, being too small to explain the significant elevation in mutation frequency observed. On the other hand, internal exposure due to uptake of radioactive nuclides was estimated to be 125 mrad (1.25 mGy) as an accumulated effective dose, mainly based on a gamma-spectrometrical analysis. However, it seemed highly likely that this value of internal exposure was a considerable underestimate, and the internal exposure was considered to be more significant than the external exposure.

Childrearing Violence and Child Adjustment Following Exposure to Kenyan Post-election Violence

PubMed Central

Skinner, Ann T.; Oburu, Paul; Lansford, Jennifer E.; Bacchini, Dario

2014-01-01

Objective This study examines parents' and children's exposure to short-term political violence and the relation between childrearing violence and child adjustment following widespread violence that erupted in Kisumu, Kenya after the disputed presidential election in December 2007. Method Mothers of 100 Luo children (mean age = 8.46 years, 61% female) reported on their own use of childrearing violence at Time 1, approximately 4 months after the disputed election, and again at Times 2 (n = 95) and 3 (n = 95), approximately 12 and 24 months later, respectively. At Time 2, mothers reported about post-election violence directed at them and about their children's exposure to post-election violence. Children reported about their own externalizing behaviors at Times 1, 2, and 3. Results Children's exposure to post-election violence was related to Time 2 externalizing behavior, and childrearing violence at Time 1 predicted child externalizing behavior at Time 2. Exposure to post-election violence was not directly related to either childrearing violence or children's externalizing behavior by Time 3, although children's externalizing at Time 2 predicted more childrearing violence at Time 3. Conclusion These results support earlier work that links childrearing violence and children's exposure to political violence with increases in child externalizing behavior, but examined these links in the under-studied area of short-term political violence. Even though sudden and severe political violence may subside significantly in weeks or months, increased attention to long-term effects on parenting and child adjustment is warranted. PMID:24639914

Childrearing Violence and Child Adjustment Following Exposure to Kenyan Post-election Violence.

PubMed

Skinner, Ann T; Oburu, Paul; Lansford, Jennifer E; Bacchini, Dario

2014-01-01

This study examines parents' and children's exposure to short-term political violence and the relation between childrearing violence and child adjustment following widespread violence that erupted in Kisumu, Kenya after the disputed presidential election in December 2007. Mothers of 100 Luo children (mean age = 8.46 years, 61% female) reported on their own use of childrearing violence at Time 1, approximately 4 months after the disputed election, and again at Times 2 ( n = 95) and 3 ( n = 95), approximately 12 and 24 months later, respectively. At Time 2, mothers reported about post-election violence directed at them and about their children's exposure to post-election violence. Children reported about their own externalizing behaviors at Times 1, 2, and 3. Children's exposure to post-election violence was related to Time 2 externalizing behavior, and childrearing violence at Time 1 predicted child externalizing behavior at Time 2. Exposure to post-election violence was not directly related to either childrearing violence or children's externalizing behavior by Time 3, although children's externalizing at Time 2 predicted more childrearing violence at Time 3. These results support earlier work that links childrearing violence and children's exposure to political violence with increases in child externalizing behavior, but examined these links in the under-studied area of short-term political violence. Even though sudden and severe political violence may subside significantly in weeks or months, increased attention to long-term effects on parenting and child adjustment is warranted.

Natural Radiation from Soil using Gamma-Ray Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silveira, M. A. G.; Moreira, R. H.; Paula, A. L. C. de

2009-06-03

We have studied the distribution of natural radioactivity in the soil of Interlagos, in Sao Paulo city and Billings Reservoir, in Sao Bernardo do Campo, Sao Paulo, Brazil. The main contribution of the effective radiation dose is due to the elements of the {sup 238}Th decay series, with smaller contributions from {sup 40}K and the elements of the series of {sup 238}U. The results indicate the dose in all of the studied areas is around the average international dose due to external exposure to gamma rays (0.48 mSv/yr) proceeding from natural terrestrial elements.

Prospective Effects of Violence Exposure across Multiple Contexts on Early Adolescents' Internalizing and Externalizing Problems

ERIC Educational Resources Information Center

Mrug, Sylvie; Windle, Michael

2010-01-01

Background: Violence exposure within each setting of community, school, or home has been linked with internalizing and externalizing problems. Although many children experience violence in multiple contexts, the effects of such cross-contextual exposure have not been studied. This study addresses this gap by examining independent and interactive…

Community Violence and Externalizing Problems: Moderating Effects of Race and Religiosity in Emerging Adulthood

ERIC Educational Resources Information Center

Fowler, Patrick J.; Ahmed, Sawssan R.; Tompsett, Carolyn J.; Jozefowicz-Simbeni, Debra M. H.; Toro, Paul A.

2008-01-01

The present study examined racial differences in the relationship between exposure to community violence and public and private religiosity in predicting externalizing problems among at-risk emerging adults. Participants were 178 African American and 163 European American emerging adults at risk for exposure to community violence. Exposure to…

Radiation exposure and disease questionnaires of early entrants after the Hiroshima bombing.

PubMed

Imanaka, Tetsuji; Endo, Satoru; Kawano, Noriyuki; Tanaka, Kenichi

2012-03-01

It is popularly known that people who entered into the ground-zero area shortly after the atomic bombings in Hiroshima and Nagasaki suffered from various syndromes similar to acute radiation effects. External exposures from neutron-induced radionuclides in soil have recently been reassessed based on DS02 calculations as functions of both distance from the hypocentres and elapsed time after the explosions. Significant exposure due to induced radiation can be determined for those who entered the area within 1000 m from the hypocentres shortly after the bombing. Although it was impossible to track the action of each of the survivors over the days or weeks following the bombings in order to make reliable dose estimates for their exposures to soil activation or fallout, four individuals among those early entrants were investigated here to describe useful information of what happened shortly after the bombing.

Climate change and safety at work with ionizing radiations.

PubMed

Contessa, Gian Marco; Grandi, Carlo; Scognamiglio, Mario; Genovese, Elisabetta; Sandri, Sandro

2016-01-01

The accident at Tokyo Electric Power Company's (TEPCO's) Fukushima Daiichi nuclear power plant (NPP) has been one of the dominant topic in nuclear safety and it has brought new attention on the matter of accidents in NPPs due to external events related to natural causes. Climate change has risen new risks and the growing probability of extreme external events has increased exposure and vulnerability of workers in the nuclear sector. However extreme natural events are a threat not only to NPPs but to all facilities dealing with radioactive material and in an emergency scenario they can affect the effectiveness and implementation of safety devices and procedures and also prevent communications, causing delays in the readiness of response. It is clear that adaptation strategies are necessary to cope with emerging changes in climate and a new nuclear safety culture is growing, that addresses accidents initiated not only by internal but also by external events.

Exposure to Violence and Socioemotional Adjustment in Low-Income Youth: An Examination of Protective Factors

PubMed Central

Hardaway, Cecily R.; McLoyd, Vonnie C.; Wood, Dana

2014-01-01

Using a sample of 391 low-income youth ages 13 to 17, this study investigated the potential moderating effects of school climate, participation in extracurricular activities, and positive parent-child relations on associations between exposure to violence (i.e., witnessing violence and violent victimization) and adolescent socioemotional adjustment (i.e., internalizing and externalizing problems). Exposure to violence was related to both internalizing and externalizing problems. High levels of participation in extracurricular activities and positive parent-child relations appeared to function as protective factors, weakening the positive association between exposure to violence and externalizing problems. Contrary to prediction, school climate did not moderate associations between exposure to violence and socioemotional adjustment. Further, none of the hypothesized protective factors moderated the association between exposure to violence and internalizing problems. PMID:21607826

Doses from radon 222 irradiation for workers of the granite mining industry.

PubMed

Сrygorieva, L; Tomilin, Yu

2017-12-01

determining the integral value of annual effective dose from 222Rn for workers of the granite mining industry and assessment for the expected life effective dose from 222Rn. Materials were the results of measurements of external exposure dose of radiation measurements equiv alent equilibrium volume activity of 222Rn in workrooms and workplaces of major groups of granite quarry workers Mykolaiv region, studies EROA 222Rn air premises of these workers, research content 222Rn in drinking water. Granite quarry workers receive double radiation exposure of 222Rn due to exposure in the workplace and at home. The load in the workplace due to inhalation of 222Rn the air was (2.1 ± 0.2) mSv / year (vari ation 0.9-5.9) in a residential area - (4,1 ± 0,2) mSv/year (variation 1.8-5.9). The total annual effective dose from internal exposure from air flow and working premises and drinking water was on average (6,5 ± 0,2) mSv/year, equal to a maximum value of 20 mSv/year. The expected life for the chronic exposure dose of technological naturally occurring radioactive sources for people who work in the granite quarries and, while living in high risk from radon is in the range of 0.16-1.12 Sv. The research results indicate that in assessing the effects associated with exposure due to radon 222 contingents persons such surveys must take into account all sources of this radionuclide dose. L. Сrygorieva, Yu. Tomilin.

Mercury risk assessment combining internal and external exposure methods for a population living near a municipal solid waste incinerator.

PubMed

Deng, Chunyan; Xie, Han; Ye, Xuejie; Zhang, Haoran; Liu, Maodian; Tong, Yindong; Ou, Langbo; Yuan, Wen; Zhang, Wei; Wang, Xuejun

2016-12-01

Risk assessments for human health have been conducted for municipal solid waste incinerators (MSWIs) in many western countries, whereas only a few risk assessments have been performed for MSWIs in developing countries such as China where the use of waste incineration is increasing rapidly. To assess the mercury exposure risks of a population living near the largest MSWI in South China, we combined internal exposure and external exposure assessment with an individual-specific questionnaire. The mercury concentrations in air, soil, and locally collected food around the MSWI were assessed. The total mercury (T-Hg) and methylmercury (MeHg) of 447 blood samples from a control group, residential exposure group, and MSWI workers were measured. The internal and external exposures of the subject population were analyzed. Significant difference in MeHg concentrations was observed between the control group and the exposed group, between the control group and the MSWI workers, and between the exposed group and the MSWI workers (median levels: 0.70 μg/L, 0.81 μg/L, and 1.02 μg/L for the control group, exposed group, and MSWI workers, respectively). The MeHg/T-Hg ratio was 0.51 ± 0.19, 0.59 ± 0.17 and 0.58 ± 0.25, respectively. Multiple linear regression analysis indicated that MeHg concentrations were positively correlated with the gaseous mercury in the air. Combining internal and external exposure assessment showed that the direct contribution of MSWI emissions was minor compared with the dietary contribution. The external and internal exposures were well matched with each other. This study also suggested that an integrated method combining internal and external exposure assessment with an individual-specific questionnaire is feasible to assess the risks for a population living near a MSWI. Copyright © 2016 Elsevier Ltd. All rights reserved.

External dose assessment in the Ukraine following the Chernobyl accident

NASA Astrophysics Data System (ADS)

Frazier, Remi Jordan Lesartre

While the physiological effects of radiation exposure have been well characterized in general, it remains unclear what the relationship is between large-scale radiological events and psychosocial behavior outcomes in individuals or populations. To investigate this, the National Science Foundation funded a research project in 2008 at the University of Colorado in collaboration with Colorado State University to expand the knowledge of complex interactions between radiation exposure, perception of risk, and psychosocial behavior outcomes by modeling outcomes for a representative sample of the population of the Ukraine which had been exposed to radiocontaminant materials released by the reactor accident at Chernobyl on 26 April 1986. In service of this project, a methodology (based substantially on previously published models specific to the Chernobyl disaster and the Ukrainian population) was developed for daily cumulative effective external dose and dose rate assessment for individuals in the Ukraine for as a result of the Chernobyl disaster. A software platform was designed and produced to estimate effective external dose and dose rate for individuals based on their age, occupation, and location of residence on each day between 26 April 1986 and 31 December 2009. A methodology was developed to transform published 137Cs soil deposition contour maps from the Comprehensive Atlas of Caesium Deposition on Europe after the Chernobyl Accident into a geospatial database to access these data as a radiological source term. Cumulative effective external dose and dose rate were computed for each individual in a 703-member cohort of Ukrainians randomly selected to be representative of the population of the country as a whole. Error was estimated for the resulting individual dose and dose rate values with Monte Carlo simulations. Distributions of input parameters for the dose assessment methodology were compared to computed dose and dose rate estimates to determine which parameters were driving the computed results. The mean external effective dose for all individuals in the cohort due to exposure to radiocontamination from the Chernobyl accident between 26 April 1986 and 31 December 2009 was found to be 1.2 mSv; the geometric mean was 0.84 mSv with a geometric standard deviation of 2.1. The mean value is well below the mean external effective dose expected due to typical background radiation (which in the United States over this time period would be 12.0 mSv). Sensitivity analysis suggests that the greatest driver of the distribution of individual dose estimates is lack of specific information about the daily behavior of each individual, specifically the portion of time each individual spent indoors (and shielded from radionuclides deposited on the soil) versus outdoors (and unshielded).

Persistence of external signs in Pacific herring Clupea pallasii Valenciennes with ichthyophoniasis

USGS Publications Warehouse

Hart, Lucas M.; Conway, Carla M.; Elliott, Diane G.; Hershberger, Paul K.

2016-01-01

The progression of external signs of Ichthyophonus infection in Pacific herring Clupea pallasii Valenciennes was highly variable and asynchronous after intraperitoneal injection with pure parasite preparations; however, external signs generally persisted through the end of the study (429 days post-exposure). Observed signs included papules, erosions and ulcers. The prevalence of external signs plateaued 35 days post-exposure and persisted in 73–79% of exposed individuals through the end of the first experiment (147 days post-exposure). Among a second group of infected herring, external signs completely resolved in only 10% of the fish after 429 days. The onset of mortality preceded the appearance of external signs. Histological examination of infected skin and skeletal muscle tissues indicated an apparent affinity of the parasite for host red muscle. Host responses consisted primarily of granulomatous inflammation, fibrosis and necrosis in the skeletal muscle and other tissues. The persistence and asynchrony of external signs and host response indicated that they were neither a precursor to host mortality nor did they provide reliable metrics for hindcasting on the date of exposure. However, the long-term persistence of clinical signs in Pacific herring may be useful in ascertaining the population-level impacts of ichthyophoniasis in regularly observed populations.

The Effects of Child Abuse and Exposure to Domestic Violence on Adolescent Internalizing and Externalizing Behavior Problems.

PubMed

Moylan, Carrie A; Herrenkohl, Todd I; Sousa, Cindy; Tajima, Emiko A; Herrenkohl, Roy C; Russo, M Jean

2010-01-01

This study examines the effects of child abuse and domestic violence exposure in childhood on adolescent internalizing and externalizing behaviors. Data for this analysis are from the Lehigh Longitudinal Study, a prospective study of 457 youth addressing outcomes of family violence and resilience in individuals and families. Results show that child abuse, domestic violence, and both in combination (i.e., dual exposure) increase a child's risk for internalizing and externalizing outcomes in adolescence. When accounting for risk factors associated with additional stressors in the family and surrounding environment, only those children with dual exposure had an elevated risk of the tested outcomes compared to non-exposed youth. However, while there were some observable differences in the prediction of outcomes for children with dual exposure compared to those with single exposure (i.e., abuse only or exposure to domestic violence only), these difference were not statistically significant. Analyses showed that the effects of exposure for boys and girls are statistically comparable.

HOx radical chemistry in oxidation flow reactors with low-pressure mercury lamps systematically examined by modeling

NASA Astrophysics Data System (ADS)

Peng, Z.; Day, D. A.; Stark, H.; Li, R.; Palm, B. B.; Brune, W. H.; Jimenez, J. L.

2015-04-01

Oxidation flow reactors (OFRs) using OH produced from low-pressure Hg lamps at 254 nm (OFR254) or both 185 and 254 nm (OFR185) are commonly used in atmospheric chemistry and other fields. OFR254 requires the addition of externally formed O3 since OH is formed from O3 photolysis, while OFR185 does not since O2 can be photolyzed to produce O3 and OH can also be formed from H2O photolysis. In this study, we use a plug-flow kinetic model to investigate OFR properties under a very wide range of conditions applicable to both field and laboratory studies. We show that the radical chemistry in OFRs can be characterized as a function of UV light intensity, H2O concentration, and total external OH reactivity (OHRext, e.g., from VOCs, NOx, and SO2). OH exposure is decreased by added external OH reactivity. OFR185 is especially sensitive to this effect at low UV intensity due to low primary OH production. OFR254 can be more resilient against OH suppression at high injected O3 (e.g., 70 ppm), as a larger primary OH source from O3, as well as enhanced recycling of HO2 to OH, make external perturbations to the radical chemistry less significant. However if the external OH reactivity in OFR254 is much larger than OH reactivity from injected O3, OH suppression can reach two orders of magnitude. For a typical input of 7 ppm O3 (OHRO3 = 10 s-1) ten-fold OH suppression is observed at OHRext ∼ 100 s-1, which is similar or lower than used in many laboratory studies. This finding may have important implications for the interpretation of past laboratory studies, as applying OHexp measurements acquired under different conditions could lead to over an order-of-magnitude error in the estimated OHexp. The uncertainties of key model outputs due to uncertainty in all rate constants and absorption cross-sections in the model are within ± 25% for OH exposure and within ± 60% for other parameters. These uncertainties are small relative to the dynamic range of outputs. Uncertainty analysis shows that most of the uncertainty is contributed by photolysis rates of O3, O2, and H2O and reactions of OH and HO2 with themselves or with some abundant species, i.e., O3 and H2O2. Using HOx-recycling vs. destructive external OH reactivity only leads to small changes in OHexp under most conditions. Changing the identity (rate constant) of external OH reactants can result in substantial changes in OHexp due to different reductions in OH suppression as the reactant is consumed. We also report two equations for estimating OH exposure in OFR254. We find that the equation estimating OHexp from measured O3 consumption performs better than an alternative equation that does not use it, and thus recommend measuring both input and output O3 concentrations in OFR254 experiments. This study contributes to establishing a firm and systematic understanding of the gas-phase HOx and Ox chemistry in these reactors, and enables better experiment planning and interpretation as well as improved design of future reactors.

Prenatal Exposure to Perfluoroalkyl Substances and Behavioral Development in Children.

PubMed

Quaak, Ilona; de Cock, Marijke; de Boer, Michiel; Lamoree, Marja; Leonards, Pim; van de Bor, Margot

2016-05-19

In recent years, prevalence rates of behavioral disorders in children have increased. One factor possibly implied in the etiology of behavioral disorders is exposure to perfluoroalkyl substances (PFASs). The use of PFASs is highly integrated into everyday life, and exposure is ubiquitous. Exposure to PFASs during early life may be particularly harmful, as it represents a critical time window for brain development. However, research in the area is limited, especially among preschool children. The objective of the current study was to explore the relationship between prenatal exposure to several PFASs and behavioral development at the age of 18 months. Data from the Dutch cohort LINC (Linking Maternal Nutrition to Child Health) were used. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were measured in cord plasma. The total exposure of PFASs was also calculated (ΣPFASs). Behavioral development was assessed with the Child Behavior Checklist 1.5-5 (CBCL 1.5-5). The CBCL scales "Attention Deficit Hyperactivity Disorder" (ADHD) and "Externalizing problems" were used for further analysis. Separate regression models were composed for each combination, in which exposure levels were classified in tertiles. Both whole population and sex-stratified analyses were performed. A family history of ADHD, the educational level, smoking or using alcohol or illicit drugs during pregnancy were considered as confounders. In total, data from 76 mother-child pairs was included. No significant associations were found between prenatal PFAS exposure and ADHD scores in the whole population and in the sex-stratified analyses. With regard to externalizing behavior, a significant negative association was found between the highest levels of ΣPFAS exposure and externalizing problem behavior in the whole population, but only in the crude model. After stratifying for sex, boys in the second and third tertile of exposure to PFOA presented significantly lower scores on the Externalizing Problem Scale than boys with the lowest exposure levels in the adjusted model. Girls exposed to higher levels of ΣPFAS exposure (T2) showed significantly lower scores on the Externalizing Problem Scale, in both crude and adjusted models. No significant associations with PFOS were found. RESULTS from the current study show that prenatal exposure to PFOA was negatively related to externalizing behavior in boys. RESULTS were different for boys and girls, emphasizing that mechanisms at work might be sex-dependent. However, results should be interpreted with caution as the sample size was small.

Space Station as a Long Duration Exposure Facility

NASA Technical Reports Server (NTRS)

Folley, Adrienne; Scheib, Jim

1995-01-01

There is need for a space platform for experiments investigating long duration exposure to space. This platform should be maintainable in the event of a malfunction, and experiments should be easily recoverable for analysis on Earth. The International Space Station provides such a platform. The current Space Station configuration has six external experiment attachment sites, providing utilities and data support distributed along the external truss. There are also other sites that could potentially support long duration exposure experiments. This paper describes the resources provided to payloads at these sites, and cites examples of integration of proposed long duration exposure experiments on these sites. The environments to which external attached payloads will be exposed are summarized.

Effect of thermal and thermo-mechanical cycling on the boron segregation behavior in the coarse-grained heat-affected zone of low-alloy steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sanghoon; Kang, Yongjoon; Lee, Changhee, E-mail: chlee@hanyang.ac.kr

The boron segregation behavior in the coarse-grained heat-affected zone (CGHAZ) of 10 ppm boron-added low-alloy steel during the welding cycle was investigated by taking the changes in the microstructure and hardness into account. Various CGHAZs were simulated with a Gleeble system as a function of the heat input and external stress, and the boron segregation behavior was analyzed by secondary ion mass spectrometry (SIMS) and particle tracking autoradiography (PTA). The segregation of boron was found to initially increase, and then decrease with an increase in the heat input. This is believed to be due to the back-diffusion of boron withmore » an increase in the exposure time at high temperature after non-equilibrium grain boundary segregation. The grain boundary segregation of boron could be decreased by an external stress applied during the welding cycle. Such behavior may be due to an increase in the grain boundary area as a result of the grain size reduction induced by the external stress. - Highlights: • Boron segregation behavior in the CGHAZ of low-alloy steel during a welding cycle was investigated. • Various CGHAZs were simulated with a Gleeble system as a function of the heat input and external stress. • Boron segregation behavior was analyzed using SIMS and PTA techniques.« less

Is received dose from ingested soil independent of soil PAH concentrations?-Animal model results.

PubMed

Peters, Rachel E; James, Kyle; Cave, Mark; Wickstrom, Mark; Siciliano, Steven D

2016-09-01

Polycyclic aromatic hydrocarbon (PAH) bioavailability from ingested soils will vary between soils; however, the nature of this variation is not well characterized. A juvenile swine model was used to link external exposure to internal benzo[a]pyrene (BaP) and anthracene exposure following oral PAH ingestion of 27 different impacted site soils, soots, or spiked artificial soils. Internal exposure of BaP and anthracene, represented by area under the plasma-time curve, did not relate to soil concentration in impacted site soils, but did relate in spiked artificial soil. Point of departure modeling identified soil PAH concentrations greater than 1900 mg kg(-1) as the point where area under the curve becomes proportional to external dose. A BaP internal exposure below 1900 mg kg(-1) had an upper 95% confidence interval estimate of 33% of external exposure. Weak relationships between soil:simulated gastrointestinal fluid PAH partitioning and area under the curve values suggest that differences in internal PAH exposure between soils may not be dominated by differences in PAH partitioning. The data seem to best support exposure assessment assuming constant internal PAH exposure below soil concentrations of 1900 mg kg(-1) . However, because constant internal exposure would challenge several existing paradigms, a bioavailability estimate of 33% of the external exposure is suggested as a likely workable solution. Environ Toxicol Chem 2016;35:2261-2269. © 2016 SETAC. © 2016 SETAC.

[Reddish discoloration of the vascular intima in charred bodies].

PubMed

Stiller, Dankwart; Lang, Juliane; Kleiber, Manfred; Rüdiger Lessig; Bohnert, Michael

2015-01-01

During the autopsy of fire victims, one often sees intensive reddening of the inner vascular layers resembling changes due to putrefaction. To determine the frequency of this phenomenon and the circumstances under which it occurs, in particular the presence of putrescence, signs of vitality and the extent of destruction by the fire, the fire fatalities autopsied at the Institutes of Legal Medicine in Freiburg, Halle and Würzburg were analyzed. In the concrete study, 259 fire deaths were investigated retrospectively and 21 prospectively. The study material included 191 males and 68 females aged 0 to 93 years. Vital exposure to the fire was found in 70%, perimortal exposure in 23 % and postmortem exposure in 7% of the cases. Red discoloration of the intima of the central vessels was seen in 106 victims (41%). This finding is most likely caused by postmortem heat-induced hemolysis, which occurs when the temperature in the body rises above 52 °C due to the effect of external heat. Therefore, a reddish discoloration of the intima cannot be regarded as sign of vitality.

Resistance to disuse atrophy in a turtle hindlimb muscle.

PubMed

McDonagh, J C; Callister, R J; Favron, M L; Stuart, D G

2004-04-01

The purpose of this study was to characterize the changes in a turtle hindlimb muscle (external gastrocnemius) after exposure to three conditions of disuse: immobilization, tenotomy, and spinalization. Histochemical analysis and measurement of muscle fiber cross-sectional area and weighted cross-sectional area were used to assess the potential conversion of muscle fiber types and changes in fiber size. It was found that unlike its counterpart in mammalian endotherms, the external gastrocnemius muscle of the adult turtle, Trachemys scripta elegans, was remarkably resistant to each model of reduced muscle function. It is suggested that such resistance to disuse is due to intrinsic mechanisms that enable heterothermic mammals and ectothermic vertebrates to tolerate an unfavorable climate and food and water shortages by using hypometabolic states.

The moderating role of food cue sensitivity in the behavioral response of children to their neighborhood food environment: a cross-sectional study.

PubMed

Paquet, Catherine; de Montigny, Luc; Labban, Alice; Buckeridge, David; Ma, Yu; Arora, Narendra; Dubé, Laurette

2017-07-05

Neighborhood food cues have been inconsistently related to residents' health, possibly due to variations in residents' sensitivity to such cues. This study sought to investigate the degree to which children's predisposition to eat upon exposure to food environment and food cues (external eating), could explain differences in strength of associations between their food consumption and the type of food outlets and marketing strategies present in their neighborhood. Data were obtained from 616 6-12 y.o. children recruited into a population-based cross-sectional study in which food consumption was measured through a 24-h food recall and responsiveness to food cues measured using the external eating scale. The proportion of food retailers within 3 km of residence considered as "healthful" was calculated using a Geographical Information System. Neighborhood exposure to food marketing strategies (displays, discount frequency, variety, and price) for vegetables and soft drinks were derived from a geocoded digital marketing database. Adjusted mixed models with spatial covariance tested interaction effects of food environment indicators and external eating on food consumption. In children with higher external eating scores, healthful food consumption was more positively related to vegetable displays, and more negatively to the display and variety of soft drinks. No interactions were observed for unhealthful food consumption and no main effects of food environment indicators were found on food consumption. Children differ in their responsiveness to marketing-related visual food cues on the basis of their external eating phenotype. Strategies aiming to increase the promotion of healthful relative to unhealthful food products in stores may be particularly beneficial for children identified as being more responsive to food cues.

PBPK and population modelling to interpret urine cadmium concentrations of the French population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Béchaux, Camille, E-mail: Camille.bechaux@anses.fr; Bodin, Laurent; Clémençon, Stéphan

As cadmium accumulates mainly in kidney, urinary concentrations are considered as relevant data to assess the risk related to cadmium. The French Nutrition and Health Survey (ENNS) recorded the concentration of cadmium in the urine of the French population. However, as with all biomonitoring data, it needs to be linked to external exposure for it to be interpreted in term of sources of exposure and for risk management purposes. The objective of this work is thus to interpret the cadmium biomonitoring data of the French population in terms of dietary and cigarette smoke exposures. Dietary and smoking habits recorded inmore » the ENNS study were combined with contamination levels in food and cigarettes to assess individual exposures. A PBPK model was used in a Bayesian population model to link this external exposure with the measured urinary concentrations. In this model, the level of the past exposure was corrected thanks to a scaling function which account for a trend in the French dietary exposure. It resulted in a modelling which was able to explain the current urinary concentrations measured in the French population through current and past exposure levels. Risk related to cadmium exposure in the general French population was then assessed from external and internal critical values corresponding to kidney effects. The model was also applied to predict the possible urinary concentrations of the French population in 2030 assuming there will be no more changes in the exposures levels. This scenario leads to significantly lower concentrations and consequently lower related risk. - Highlights: • Interpretation of urine cadmium concentrations in France • PBPK and Bayesian population modelling of cadmium exposure • Assessment of the historic time-trend of the cadmium exposure in France • Risk assessment from current and future external and internal exposure.« less

Exposure to Community Violence and the Trajectory of Internalizing and Externalizing Symptoms in a Sample of Low-Income Urban Youth.

PubMed

Taylor, Jeremy J; Grant, Kathryn E; Zulauf, Courtney A; Fowler, Patrick J; Meyerson, David A; Irsheid, Sireen

2018-01-01

This study examined trajectories of psychopathology in a sample of low-income urban youth and tested exposure to community violence as a predictor of these trajectories. Self-report and parent-report survey measures of psychological problems and exposure to community violence were collected annually over 3 years from a sample of 364 fifth- to ninth-grade low-income urban youth (64% female; 95% youth of color). Linear growth models showed that youth experienced declines in both internalizing and externalizing symptoms across adolescence. Exposure to community violence was more strongly associated with externalizing symptoms than with internalizing symptoms but predicted declines in both types of symptoms. Results also indicated that youth reported more internalizing and externalizing symptoms than their parents reported for them. Exposure to community violence may explain unique trajectories of mental health problems among low-income urban youth. In addition, youth efforts to adopt a tough façade in the face of community violence could lead to higher rates of externalizing problems relative to internalizing problems, whereas desensitization processes may better explain reductions in both types of symptoms over time. Finally, youth report may be more valid than parent report in the context of urban poverty.

End-stage renal disease after occupational lead exposure: 20 years of follow-up.

PubMed

Evans, Marie; Discacciati, Andrea; Quershi, Abdul Rashid; Åkesson, Agneta; Elinder, Carl-Gustaf

2017-06-01

Whether low-level exposure to lead may give rise to chronic kidney disease or end-stage renal disease (ESRD) is debated. In this study, we aimed to specifically investigate if low-level occupational exposure to lead was associated with increased incidence of ESRD. The incidence of starting renal replacement therapy as a result of ESRD was examined in a cohort of10 303 lead-workers who had controlled blood lead concentrations due to a compulsory occupational health surveillance programme in Sweden during the time period 1977-1990. The ESRD incidence (obtained through register-linkage) among the lead-exposed workers was compared with the age, sex and calendar period-adjusted expected incidence based on data from the Swedish renal registry. Dose-response association was evaluated in external (general population) and internal (within the occupational cohort) comparisons by highest achieved blood lead level. There were 30 (0.29%) individuals in the cohort who developed ESRD during the median follow-up period of 26.3 years. The standardised incidence ratio (SIR) for ESRD incidence was 0.79 (95% CI 0.54 to 1.13). Among those who achieved the highest blood lead (>41.4 µg/dL), the SIR was 1.01 (0.44 to 1.99). There was no evidence of a dose-response relationship between the maximum achieved blood lead or the cumulative blood lead exposure and ESRD in external or internal comparisons. This study of workers with documented occupational lead exposures followed for 20 years shows no statistically significant association between lead exposure (following the current occupational recommendations for Sweden) and ESRD. 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/.

Critical time delay of the pineal melatonin rhythm in humans due to weak electromagnetic exposure.

PubMed

Halgamuge, Malka N

2013-08-01

Electromagnetic fields (EMFs) can increase free radicals, activate the stress response and alter enzyme reactions. Intracellular signalling is mediated by free radicals and enzyme kinetics is affected by radical pair recombination rates. The magnetic field component of an external EMF can delay the "recombination rate" of free radical pairs. Magnetic fields thus increase radical life-times in biological systems. Although measured in nanoseconds, this extra time increases the potential to do more damage. Melatonin regulates the body's sleep-wake cycle or circadian rhythm. The World Health Organization (WHO) has confirmed that prolonged alterations in sleep patterns suppress the body's ability to make melatonin. Considerable cancer rates have been attributed to the reduction of melatonin production as a result of jet lag and night shift work. In this study, changes in circadian rhythm and melatonin concentration are observed due to the external perturbation of chemical reaction rates. We further analyze the pineal melatonin rhythm and investigate the critical time delay or maturation time of radical pair recombination rates, exploring the impact of the mRNA degradation rate on the critical time delay. The results show that significant melatonin interruption and changes to the circadian rhythm occur due to the perturbation of chemical reaction rates, as also reported in previous studies. The results also show the influence of the mRNA degradation rate on the circadian rhythm's critical time delay or maturation time. The results support the hypothesis that exposure to weak EMFs via melatonin disruption can adversely affect human health.

Indoor External Radiation Risk in Densely Populated Regions of Southern Nigeria

NASA Astrophysics Data System (ADS)

Ife-Adediran, Oluwatobi O.; Uwadiae, Iyobosa B.

2018-02-01

It is known that certain types of building materials contain significant concentrations of natural radionuclides; consequently, exposure to indoor background radiation is from the combined radioactivity from the soil as well as building materials; indoor exposures therefore have higher radiation hazard potentials than outdoor exposures in this regard and hence, need to be monitored. In this paper, an evaluation of background ionizing radiation from different buildings in Lagos and Ibadan, Southwestern Nigeria was carried out to determine the exposure rate of the general public to indoor ionizing radiation. 630 in situ measurements from the different buildings were taken using a Geiger Muller counter (model GQ-320 Plus). The indoor dose rates (i.e., 50-120 nGy/h) were within the world average values while the Annual Effective Dose for most of the buildings were above the world average AED for indoor gamma exposure from building materials. The mean AED for Lagos and Ibadan due to indoor exposures were 0.37 and 0.39 mSv/y with Excess Lifetime Cancer Risk of 0.99E-3 and 1.05E-3, respectively.

Indoor External Radiation Risk in Densely Populated Regions of Southern Nigeria

NASA Astrophysics Data System (ADS)

Ife-Adediran, Oluwatobi O.; Uwadiae, Iyobosa B.

2018-05-01

It is known that certain types of building materials contain significant concentrations of natural radionuclides; consequently, exposure to indoor background radiation is from the combined radioactivity from the soil as well as building materials; indoor exposures therefore have higher radiation hazard potentials than outdoor exposures in this regard and hence, need to be monitored. In this paper, an evaluation of background ionizing radiation from different buildings in Lagos and Ibadan, Southwestern Nigeria was carried out to determine the exposure rate of the general public to indoor ionizing radiation. 630 in situ measurements from the different buildings were taken using a Geiger Muller counter (model GQ-320 Plus). The indoor dose rates (i.e., 50-120 nGy/h) were within the world average values while the Annual Effective Dose for most of the buildings were above the world average AED for indoor gamma exposure from building materials. The mean AED for Lagos and Ibadan due to indoor exposures were 0.37 and 0.39 mSv/y with Excess Lifetime Cancer Risk of 0.99E-3 and 1.05E-3, respectively.

Selective Shielding of Bone Marrow: An Approach to Protecting Humans from External Gamma Radiation.

PubMed

Waterman, Gideon; Kase, Kenneth; Orion, Itzhak; Broisman, Andrey; Milstein, Oren

2017-09-01

The current feasibility of protecting emergency responders through bone marrow selective shielding is highlighted in the recent OECD/NEA report on severe accident management. Until recently, there was no effective personal protection from externally penetrating gamma radiation. In Chernobyl, first-responders wore makeshift lead sheeting, whereas in Fukushima protective equipment from gamma radiation was not available. Older protective solutions that use thin layers of shielding over large body surfaces are ineffective for energetic gamma radiation. Acute exposures may result in Acute Radiation Syndrome where the survival-limiting factor up to 10 Gy uniform, homogeneous exposure is irreversible bone marrow damage. Protracted, lower exposures may result in malignancies of which bone marrow is especially susceptible, being compounded by leukemia's short latency time. This highlights the importance of shielding bone marrow for preventing both deterministic and stochastic effects. Due to the extraordinary regenerative potential of hematopoietic stem cells, to effectively prevent the deterministic effects of bone marrow exposure, it is sufficient to protect only a small fraction of this tissue. This biological principle allows for a new class of equipment providing unprecedented attenuation of radiation to select marrow-rich regions, deferring the hematopoietic sub-syndrome of Acute Radiation Syndrome to much higher doses. As approximately half of the body's active bone marrow resides within the pelvis region, shielding this area holds great promise for preventing the deterministic effects of bone marrow exposure and concomitantly reducing stochastic effects. The efficacy of a device that selectively shields this region and other radiosensitive organs in the abdominal area is shown here.

A Genetically Informed Study of Associations between Family Functioning and Child Psychosocial Adjustment

PubMed Central

Schermerhorn, Alice C.; D’Onofrio, Brian M.; Turkheimer, Eric; Ganiban, Jody M.; Spotts, Erica L.; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M.

2010-01-01

Research has documented associations between family functioning and offspring psychosocial adjustment, but questions remain regarding whether these associations are partly due to confounding genetic factors and other environmental factors. The current study used a genetically informed approach, the Children of Twins design, to explore the associations between family functioning (family conflict, marital quality, and agreement about parenting) and offspring psychopathology. Participants were 867 twin pairs (388 MZ; 479 DZ) from the Twin and Offspring Study in Sweden (TOSS), their spouses, and children (51.7% female; M = 15.75 years). The results suggested associations between exposure to family conflict (assessed by the mother, father, and child) and child adjustment were independent of genetic factors and other environmental factors. However, when family conflict was assessed using only children’s reports, the results indicated that genetic factors also influenced these associations. In addition, the analyses indicated that exposure to low marital quality and agreement about parenting was associated with children’s internalizing and externalizing problems, and that genetic factors also contributed to the associations of marital quality and agreement about parenting with offspring externalizing problems. PMID:21142367

10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

Code of Federal Regulations, 2010 CFR

2010-01-01

... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy... Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive... identifying the need for posting of airborne radioactivity areas in accordance with § 835.603(d). b. The air...

Does lateral versus medial exposure influence total knee tibial component final external rotation? A CT based study.

PubMed

Passeron, D; Gaudot, F; Boisrenoult, P; Fallet, L; Beaufils, P

2009-10-01

A previous study demonstrated that performing a total knee arthroplasty through a lateral approach including anterior tibial tuberosity (ATT) osteotomy (refixed in its original position) presented numerous advantages: correcting the preoperative patella lateral tilt and improving postoperative patella tracking. We hypothesized that these improvements in patella centering were, at least in part, due to an increased external rotation of the tibial component. Postoperative scannographic studies were, therefore, undertaken to measure tibial component rotation and analyze the results according the medial and lateral exposure used. Rotational positioning of the tibial component is influenced by the lateral or medial approach selected at surgery. Forty-five CAT scans, performed according to the protocol criteria of the French Hip and Knee Society (SFHG), were studied 3 months postoperatively: 15 knees operated through the lateral approach and 30 knees operated through a standard medial approach. The total knee utilized in all these cases was a posteriorly stabilized, fixed-bearing, design. We measured first the angle formed between the perpendicular to the transverse axis of the tibial component and the axis joining the ATT to the center of the knee; second we also measured the coronal distance between the center of the component and the anterior tibial tuberosity (ATT). In the group using the medial approach, the lateral position of the ATT was 7 + or - 3mm with a rotation angle of 18 degrees . In the group using the lateral approach these measurements were respectively 1 + or - 4mm and 2 degrees (p<0.0001). External rotation of the tibial component is substantially increased by the lateral approach compared to the medial approach. Better exposure of the lateral tibial plateau is probably responsible of this difference. This increased external rotation improves postoperative patella tracking. Prospective; comparative; non-randomized study; level 3. 2009 Elsevier Masson SAS. All rights reserved.

Contamination and radiation exposure in central Europe after the Chernobyl accident

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayer, A.; Mueck, K.; Loosli, H.H.

1996-06-01

Ten years ago, on 26 April 1986, as a consequence of an accident in Unit 4 of the Chernobyl-NPP, a large quantity of radioactive material was released into the atmosphere for some days. This material was spread over wide areas of Europe. Due to variable weather conditions the activity concentrations in air varied considerably in different regions. Also as a consequence of large variations in precipitation intensity-particularly in the regions of Southeastern Germany, Austria and Southern Switzerland-up to 100 kBq m{sup -2} {sup 137}Cs were deposited on the soil. Due to fallout, washout, and/or rainout, a range of foodstuffs weremore » contaminated, and foodstuffs directly exposed to the fallout [vegetables and green fodder (grass)] showed the highest contamination levels. Consequently, milk also showed a significantly increased activity concentration, in particular of {sup 131}I. In the following years contamination in all kinds of foodstuffs decreased, but elevated contamination levels in special pathways like venison and mushrooms are still observed to date. This contamination resulted in additional exposure, mainly due to external radiation from ground and from consumption of contaminated food. The radiation exposure in the most contaminated areas was calculated on the basis of model assumptions and was found to be about 1 mSv during the first year after the accident. Using this model, the ingestion pathway was overestimated by at least a factor of two. This additional exposure decreased and is now less than 1 % on average; in the most contaminated areas, this is a few percent of the average natural radiation exposure.« less

An estimate by two methods of thyroid absorbed doses due to BRAVO fallout in several Northern Marshall Islands.

PubMed

Musolino, S V; Greenhouse, N A; Hull, A P

1997-10-01

Estimates of the thyroid absorbed doses due to fallout originating from the 1 March 1954 BRAVO thermonuclear test on Bikini Atoll have been made for several inhabited locations in the Northern Marshall Islands. Rongelap, Utirik, Rongerik and Ailinginae Atolls were also inhabited on 1 March 1954, where retrospective thyroid absorbed doses have previously been reconstructed. The current estimates are based primarily on external exposure data, which were recorded shortly after each nuclear test in the Castle Series, and secondarily on soil concentrations of 137Cs in samples collected in 1978 and 1988, along with aerial monitoring done in 1978. The external exposures and 137Cs soil concentrations were representative of the atmospheric transport and deposition patterns of the entire Castle Series tests and show that the BRAVO test was the major contributor to fallout exposure during the Castle series and other test series which were carried out in the Marshall Islands. These data have been used as surrogates for fission product radioiodines and telluriums in order to estimate the range of thyroid absorbed doses that may have occurred throughout the Marshall Islands. Dosimetry based on these two sets of estimates agreed within a factor of 4 at the locations where BRAVO was the dominant contributor to the total exposure and deposition. Both methods indicate that thyroid absorbed doses in the range of 1 Gy (100 rad) may have been incurred in some of the northern locations, whereas the doses at southern locations did not significantly exceed levels comparable to those from worldwide fallout. The results of these estimates indicate that a systematic medical survey for thyroid disease should be conducted, and that a more definitive dose reconstruction should be made for all the populated atolls and islands in the Northern Marshall Islands beyond Rongelap, Utirik, Rongerik and Ailinginae, which were significantly contaminated by BRAVO fallout.

Federal Guidance Report No. 15: External Exposure to Radionuclides in Air, Water and Soil

EPA Pesticide Factsheets

FGR 15 updates the 1993 Federal Guidance Report No. 12 (FGR 12), External Exposure to Radionuclides in Air, Water, and Soil. FGR 15 incorporates advances in radiation protection science regarding how organ/tissue doses change with age and sex.

Prism adaptation by mental practice.

PubMed

Michel, Carine; Gaveau, Jérémie; Pozzo, Thierry; Papaxanthis, Charalambos

2013-09-01

The prediction of our actions and their interaction with the external environment is critical for sensorimotor adaptation. For instance, during prism exposure, which deviates laterally our visual field, we progressively correct movement errors by combining sensory feedback with forward model sensory predictions. However, very often we project our actions to the external environment without physically interacting with it (e.g., mental actions). An intriguing question is whether adaptation will occur if we imagine, instead of executing, an arm movement while wearing prisms. Here, we investigated prism adaptation during mental actions. In the first experiment, participants (n = 54) performed arm pointing movements before and after exposure to the optical device. They were equally divided into six groups according to prism exposure: Prisms-Active, Prisms-Imagery, Prisms-Stationary, Prisms-Stationary-Attention, No Conflict-Prisms-Imagery, No Prisms-Imagery. Adaptation, measured by the difference in pointing errors between pre-test and post-test, occurred only in Prisms-Active and Prisms-Imagery conditions. The second experiment confirmed the results of the first experiment and further showed that sensorimotor adaptation was mainly due to proprioceptive realignment in both Prisms-Active (n = 10) and Prisms-Imagery (n = 10) groups. In both experiments adaptation was greater following actual than imagined pointing movements. The present results are the first demonstration of prism adaptation by mental practice under prism exposure and they are discussed in terms of internal forward models and sensorimotor plasticity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Construction of new skin models and calculation of skin dose coefficients for electron exposures

NASA Astrophysics Data System (ADS)

Yeom, Yeon Soo; Kim, Chan Hyeong; Nguyen, Thang Tat; Choi, Chansoo; Han, Min Cheol; Jeong, Jong Hwi

2016-08-01

The voxel-type reference phantoms of the International Commission on Radiological Protection (ICRP), due to their limited voxel resolutions, cannot represent the 50- μm-thick radiosensitive target layer of the skin necessary for skin dose calculations. Alternatively, in ICRP Publication 116, the dose coefficients (DCs) for the skin were calculated approximately, averaging absorbed dose over the entire skin depth of the ICRP phantoms. This approximation is valid for highly-penetrating radiations such as photons and neutrons, but not for weakly penetrating radiations like electrons due to the high gradient in the dose distribution in the skin. To address the limitation, the present study introduces skin polygon-mesh (PM) models, which have been produced by converting the skin models of the ICRP voxel phantoms to a high-quality PM format and adding a 50- μm-thick radiosensitive target layer into the skin models. Then, the constructed skin PM models were implemented in the Geant4 Monte Carlo code to calculate the skin DCs for external exposures of electrons. The calculated values were then compared with the skin DCs of the ICRP Publication 116. The results of the present study show that for high-energy electrons (≥ 1 MeV), the ICRP-116 skin DCs are, indeed, in good agreement with the skin DCs calculated in the present study. For low-energy electrons (< 1 MeV), however, significant discrepancies were observed, and the ICRP-116 skin DCs underestimated the skin dose as much as 15 times for some energies. Besides, regardless of the small tissue weighting factor of the skin ( w T = 0.01), the discrepancies in the skin dose were found to result in significant discrepancies in the effective dose, demonstarting that the effective DCs in ICRP-116 are not reliable for external exposure to electrons.

Dichlorodiphenyldichloroethylene Exposure during the First Trimester of Pregnancy Alters the Anal Position in Male Infants

PubMed Central

Torres-Sanchez, Luisa; Zepeda, Monica; Cebrián, Mariano E.; Belkind-Gerson, Jaime; Garcia-Hernandez, Rosa M.; Belkind-Valdovinos, Uri; López-Carrillo, Lizbeth

2016-01-01

Anogenital distance (AGD) at birth is regarded as a useful measurement that reflects the prenatal androgenic status in rodents. However, the impact of xenoantiandrogens on human development is largely unknown. The aim of this study was to evaluate the potential antiandrogenic impact of prenatal DDT metabolites (p,p′-DDE and p,p′-DDT) exposure on infant AGD, using a non-age–dependent anal position index (API). As part of an ongoing perinatal cohort study on the effects of organochlorine pesticides in children’s neurodevelopment, we conducted a cross-sectional study in 71 infants (37 males and 34 females). Maternal serum levels of DDT metabolites (p,p′-DDE and p,p′-DDT) before and during each trimester of pregnancy were determined by electron capture gas–liquid chromatography. During postnatal home visits at 3, 6, and 12 or 18 months of age, the children’s weight and API were evaluated. Multiple lineal regression models were used to estimate the potential endocrine disruptor activity of prenatal p,p′-DDE exposure. Boys had significantly higher API values than girls (0.6 versus 0.5; P < 0.001). Only among boys, a doubling increase of maternal p,p′-DDE serum levels during the first trimester of pregnancy, were associated with a significant reduction of API (β = −0.02; P = 0.02). No effect of p,p′-DDT on AGD was observed. Evidence of the effect of prenatal p,p′-DDE on external genital differentiation is scarce and not consistent in the literature. Further studies are needed to confirm a hormonal disruptive effect on the development of external genitalia, due not only to p,p′-DDE but also due to other antiandrogenic persistent compounds. PMID:18991914

On the use of mobile phones and wearable microphones for noise exposure measurements: Calibration and measurement accuracy

NASA Astrophysics Data System (ADS)

Dumoulin, Romain

Despite the fact that noise-induced hearing loss remains the number one occupational disease in developed countries, individual noise exposure levels are still rarely known and infrequently tracked. Indeed, efforts to standardize noise exposure levels present disadvantages such as costly instrumentation and difficulties associated with on site implementation. Given their advanced technical capabilities and widespread daily usage, mobile phones could be used to measure noise levels and make noise monitoring more accessible. However, the use of mobile phones for measuring noise exposure is currently limited due to the lack of formal procedures for their calibration and challenges regarding the measurement procedure. Our research investigated the calibration of mobile phone-based solutions for measuring noise exposure using a mobile phone's built-in microphones and wearable external microphones. The proposed calibration approach integrated corrections that took into account microphone placement error. The corrections were of two types: frequency-dependent, using a digital filter and noise level-dependent, based on the difference between the C-weighted noise level minus A-weighted noise level of the noise measured by the phone. The electro-acoustical limitations and measurement calibration procedure of the mobile phone were investigated. The study also sought to quantify the effect of noise exposure characteristics on the accuracy of calibrated mobile phone measurements. Measurements were carried out in reverberant and semi-anechoic chambers with several mobiles phone units of the same model, two types of external devices (an earpiece and a headset with an in-line microphone) and an acoustical test fixture (ATF). The proposed calibration approach significantly improved the accuracy of the noise level measurements in diffuse and free fields, with better results in the diffuse field and with ATF positions causing little or no acoustic shadowing. Several sources of errors and uncertainties were identified including the errors associated with the inter-unit-variability, the presence of signal saturation and the microphone placement relative to the source and the wearer. The results of the investigations and validation measurements led to recommendations regarding the measurement procedure including the use of external microphones having lower sensitivity and provided the basis for a standardized and unique factory default calibration method intended for implementation in any mobile phone. A user-defined adjustment was proposed to minimize the errors associated with calibration and the acoustical field. Mobile phones implementing the proposed laboratory calibration and used with external microphones showed great potential as noise exposure instruments. Combined with their potential as training and prevention tools, the expansion of their use could significantly help reduce the risks of noise-induced hearing loss.

Fallout from the Chernobyl accident and overall cancer incidence in Finland.

PubMed

Kurttio, Päivi; Seppä, Karri; Pasanen, Kari; Patama, Toni; Auvinen, Anssi; Pukkala, Eero; Heinävaara, Sirpa; Arvela, Hannu; Hakulinen, Timo

2013-10-01

We studied whether incidence of all cancer sites combined was associated with the radiation exposure due to fallout from the Chernobyl accident in Finland. An emphasis was on the first decade after the accident to assess the suggested "promotion effect". The segment of Finnish population with a stable residence in the first post-Chernobyl year (2 million people) was studied. The analyses were based on a 250m × 250m grid squares covering all of Finland and all cancer cases except cancers of the breast, prostate and lung. Cancer incidence in four exposure areas (based on first-year dose due to external exposure <0.1 mSv, 0.1-1.3, 0.3-0.5, or ≥ 0.5 mSv) was compared before the Chernobyl accident (1981-1985) and after it (1988-2007) taking into account cancer incidence trends for a longer period prior to the accident (since 1966). There were no systematic differences in the cancer incidence in relation to radiation exposure in any calendar period, or any subgroup by sex or age at accident. The current large and comprehensive cohort analysis of the relatively low levels of the Chernobyl fallout in Finland did not observe a cancer promotion effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Differences in risk and protective factors for workplace aggression between male and female clinical medical practitioners in Australia.

PubMed

Hills, Danny J

2017-07-01

Objectives The aim of the present study was to investigate differences in prevalence, as well as risk and protective factors, for exposure to workplace aggression between male and female clinicians in Australian medical practice settings. Methods In a cross-sectional, self-report study in the third wave of the Medicine in Australia: Balancing Employment and Life survey (2010-11), 16327 medical practitioners were sampled, with 9449 (57.9%) respondents working in clinical practice. Using backward stepwise elimination, parsimonious logistic regression models were developed for exposure to aggression from external (patients, patients' relatives or carers and others) and internal (co-workers) sources in the previous 12 months. Results Overall, greater proportions of female than male clinicians experienced aggression from external (P<0.001) and internal (P<0.01) sources in the previous 12 months. However, when stratified by doctor type, greater proportions of male than female general practitioners (GPs) and GP registrars experienced external aggression (P<0.05), whereas greater proportions of female than male specialists experienced external (P<0.01) and internal (P<0.01) aggression. In logistic regression models, differences were identified in relation to age for males and experience working in medicine for females with external and internal aggression; working in New South Wales (vs Victoria) and internal aggression for females; a poor medical support network and external aggression, and perceived unrealistic patient expectations with internal aggression for males; warning signs in reception and waiting areas with external aggression for males; and optimised patient waiting conditions with external and internal aggression for females. Conclusions Differences in risk and protective factors for exposure to workplace aggression between male and female clinicians, including in relation to state and rural location, need to be considered in the development and implementation of efforts to prevent and minimise workplace aggression in medical practice settings. What is known about the topic? Workplace aggression is prevalent in clinical medical settings, but there are conflicting reports about sex-based differences in the extent of exposure, and little evidence on differences in risk and protective factors for exposure to workplace aggression. What does this paper add? Differences in workplace aggression exposure rates between male and female clinicians are highlighted, including when stratified by doctor type. New evidence is reported on differences and similarities in key personal, professional and work-related factors associated with exposure to external and internal aggression. What are the implications for practitioners? In developing strategies for the prevention and minimisation of workplace aggression, consideration must be given to differences between male and female clinicians, including with regard to personality, age and professional experience, as well as work locations, conditions and settings, as risk or protective factors for exposure to aggression in medical work.

Combustion and Mixing Studies in Compressible Flows.

DTIC Science & Technology

1996-09-01

which extracts a gas sample from the supersonic mixing region and analyzes it externally using hot-wire anemometry in conjunction with pressure and...shown in 3020 cmŕ ethylene Raman line. The images were Figure 1. A Nd:YAG laser operating at its taken with an exposure time of 0.2 sec. The...pressure levels. This effect is sec. Figure 7 shows Raman images of ethylene for not visible in the 633 nm spectra due to its pressure readings of 0.15

The Hubble Space Telescope Servicing Mission 3A Contamination Control Program

NASA Technical Reports Server (NTRS)

Hansen, Patricia A.

2000-01-01

After nearly 10 years on-orbit, the Hubble Space Telescope (HST) external thermal control materials and paint have degraded due to exposure to the low Earth orbit environment. This presented a potentially large on-orbit contamination source (particles and/or debris). Contamination mitigation techniques were developed to augment existing on-orbit servicing contamination controls. They encompassed mission management, crew training, and crew aids and tools. These techniques were successfully employed during the HST Servicing Mission 3A, December 1999.

Inner Mitochondrial Membrane Disruption Links Apoptotic and Agonist-Initiated Phosphatidylserine Externalization in Platelets.

PubMed

Choo, Hyo-Jung; Kholmukhamedov, Andaleb; Zhou, ChengZing; Jobe, Shawn

2017-08-01

Phosphatidylserine exposure mediates platelet procoagulant function and regulates platelet life span. Apoptotic, necrotic, and integrin-mediated mechanisms have been implicated as intracellular determinants of platelet phosphatidylserine exposure. Here, we investigate (1) the role of mitochondrial events in platelet phosphatidylserine exposure initiated by these distinct stimuli and (2) the cellular interactions of the procoagulant platelet in vitro and in vivo. Key mitochondrial events were examined, including cytochrome c release and inner mitochondrial membrane (IMM) disruption. In both ABT-737 (apoptotic) and agonist (necrotic)-treated platelets, phosphatidylserine externalization was temporally correlated with IMM disruption. Agonist stimulation resulted in rapid cyclophilin D-dependent IMM disruption that coincided with phosphatidylserine exposure. ABT-737 treatment caused rapid cytochrome c release, eventually followed by caspase-dependent IMM disruption that again closely coincided with phosphatidylserine exposure. A nonmitochondrial and integrin-mediated mechanism has been implicated in the formation of a novel phosphatidylserine-externalizing platelet subpopulation. Using image cytometry, this subpopulation is demonstrated to be the result of the interaction of an aggregatory platelet and a procoagulant platelet rather than indicative of a novel intracellular mechanism regulating platelet phosphatidylserine externalization. Using electron microscopy, similar interactions between aggregatory and procoagulant platelets are demonstrated in vitro and in vivo within a mesenteric vein hemostatic thrombus. Platelet phosphatidylserine externalization is closely associated with the mitochondrial event of IMM disruption identifying a common pathway in phosphatidylserine-externalizing platelets. The limited interaction of procoagulant platelets and integrin-active aggregatory platelets identifies a potential mechanism for procoagulant platelet retention within the hemostatic thrombus. © 2017 American Heart Association, Inc.

Radiation exposures due to fossil fuel combustion

NASA Astrophysics Data System (ADS)

Beck, Harold L.

The current consensus regarding the potential radiation exposures resulting from the combustion of fossil fuels is examined. Sources, releases and potential doses to humans are discussed, both for power plants and waste materials. It is concluded that the radiation exposure to most individuals from any pathway is probably insignificant, i.e. only a tiny fraction of the dose received from natural sources in soil and building materials. Any small dose that may result from power-plant emissions will most likely be from inhalation of the small insoluble ash particles from the more poorly controlled plants burning higher than average activity fuel, rather than from direct or indirect ingestion of food grown on contaminated soil. One potentially significant pathway for exposure to humans that requires further evaluation is the effect on indoor external γ-radiation levels resulting from the use of flyash in building materials. The combustion of natural gas in private dwellings is also discussed, and the radiological consequences are concluded to be generally insignificant, except under certain extraordinary circumstances.

Genetic variation in GABRA2 moderates peer influence on externalizing behavior in adolescents.

PubMed

Villafuerte, Sandra; Trucco, Elisa M; Heitzeg, Mary M; Burmeister, Margit; Zucker, Robert A

2014-01-01

Genetic predisposition and environmental influences are both important factors in the development of problematic behavior leading to substance use in adolescence. Involvement with delinquent peers also strongly predicts adolescent externalizing behavior. Several lines of evidence support a role of GABRA2 on externalizing behavior related to disinhibition. However, whether this genetic association is influenced by the environment such as peer behavior remains unknown. We examined the moderating role of GABRA2 genetic variation on the socialization model of delinquent peer affiliation (at ages 12-14 years) on externalizing behavior (at ages 15-17 years) in the Michigan Longitudinal Study (MLS) adolescent sample. The sample consisted of 244 adolescents (75 females and 152 with at least one parent with a DSM-IV lifetime alcohol dependence/abuse diagnosis). Peer delinquent activity reported by the participant and teacher-reported adolescent externalizing behavior (Teacher Report Form (TRF) were assessed. No main effect of the GABRA2 SNP rs279826, which tags a large haplotype, on externalizing behavior was observed. However, there was a statistically reliable GABRA2 × peer delinquency interaction. The effect of peer delinquent involvement on externalizing scores and the rule breaking subscale is significantly stronger for those with the GG genotype compared to A-carriers, whereas there was no effect of genotype on externalizing in the absence of peer delinquent involvement. No interaction was observed for the aggression subscale. Our results suggest that the genetic effect of GABRA2 on externalizing behavior, more specifically on rule breaking is, at least in part, due to its effect on susceptibility to environmental exposure (i.e., peer delinquency).

COMMUNITY VIOLENCE AND EXTERNALIZING PROBLEMS: MODERATING EFFECTS OF RACE AND RELIGIOSITY IN EMERGING ADULTHOOD

PubMed Central

Fowler, Patrick J.; Ahmed, Sawssan R.; Tompsett, Carolyn J.; Jozefowicz-Simbeni, Debra M. H.; Toro, Paul A.

2009-01-01

The present study examined racial differences in the relationship between exposure to community violence and public and private religiosity in predicting externalizing problems among at-risk emerging adults. Participants were 178 African American and 163 European American emerging adults at risk for exposure to community violence. Exposure to community violence related to more externalizing problems. Greater public religious affiliation buffered the relationship between community violence and substance abuse, for both African American and European emerging adults. In addition, more privately religious African American emerging adults engaged in less deviant behavior when exposed to higher levels of community violence. European Americans were not protected by private religiosity. PMID:20016764

Measurement methods for human exposure analysis.

PubMed Central

Lioy, P J

1995-01-01

The general methods used to complete measurements of human exposures are identified and illustrations are provided for the cases of indirect and direct methods used for exposure analysis. The application of the techniques for external measurements of exposure, microenvironmental and personal monitors, are placed in the context of the need to test hypotheses concerning the biological effects of concern. The linkage of external measurements to measurements made in biological fluids is explored for a suite of contaminants. This information is placed in the context of the scientific framework used to conduct exposure assessment. Examples are taken from research on volatile organics and for a large scale problem: hazardous waste sites. PMID:7635110

Telomere Length in Aged Mayak PA Nuclear Workers Chronically Exposed to Internal Alpha and External Gamma Radiation.

PubMed

Scherthan, Harry; Sotnik, Natalia; Peper, Michel; Schrock, Gerrit; Azizova, Tamara; Abend, Michael

2016-06-01

Telomeres consist of GC-rich DNA repeats and the "shelterin" protein complex that together protect chromosome ends from fusion and degradation. Telomeres shorten with age due to incomplete end replication and upon exposure to environmental and intrinsic stressors. Exposure to ionizing radiation is known to modulate telomere length. However, the response of telomere length in humans chronically exposed to radiation is poorly understood. Here, we studied relative telomere length (RTL) by IQ-FISH to leukocyte nuclei in a group of 100 workers from the plutonium production facility at the Mayak Production Association (PA) who were chronically exposed to alpha-emitting ((239)Pu) radiation and/or gamma (photon) radiation, and 51 local residents serving as controls, with a similar mean age of about 80 years. We applied generalized linear statistical models adjusted for age at biosampling and the second exposure type on a linear scale and observed an age-dependent telomere length reduction. In those individuals with the lowest exposure, a significant reduction of about 20% RTL was observed, both for external gamma radiation (≤1 Gy) and internal alpha radiation (≤0.05-0.1 Gy to the red bone marrow). In highly exposed individuals (>0.1 Gy alpha, 1-1.5 Gy gamma), the RTL was similar to control. Stratification by gender revealed a significant (∼30%) telomere reduction in low-dose-exposed males, which was absent in females. While the gender differences in RTL may reflect different working conditions, lifestyle and/or telomere biology, absence of a dose response in the highly exposed individuals may reflect selection against cells with short telomeres or induction of telomere-protective effects. Our observations suggest that chronic systemic exposure to radiation leads to variable dose-dependent effects on telomere length.

Determination of cellular injury and death thresholds following exposure to high voltage 10ns electrical pulses

NASA Astrophysics Data System (ADS)

Ibey, Bennett L.; Roth, Caleb C.; Bernhard, Joshua A.; Pakhomov, Andrei G.; Wilmink, Gerald J.; Pakhomova, Olga

2011-03-01

Intense, nanosecond-duration electric pulses (nsEP) have been introduced as a novel modality to alter cellular function, with a mechanism of action qualitatively different from micro- and millisecond duration pulses used in electroporation. In this study, we determined the thresholds for plasma membrane injury (within 15 minutes) and cell death (at 24 hours) for 4 different cell types (CHO-K1, HeLa, Jurkat and U937). Plasma membrane injury was measured by flow cytometry using two fluorescent dyes, namely Annexin V-FITC, which binds to phosphatidylserine (PS) upon its externalization (subtle membrane injury), and propidium iodide (PI), which is typically impermeable to the cell, but enters when large pores are formed in the plasma membrane. In all cell types, 10-ns pulses caused phosphatidylserine (PS) externalization at low doses (<150kV/cm and 100 pulses for each cell type) and no PI uptake. Jurkat and U937 cell lines showed substantial cell death without uptake of PI (15 minutes post exposure) suggesting either delayed permeabilization due to swelling, or damage to intracellular components. In CHO-K1 and HeLa cell lines, PI uptake occurred at low doses relative to that necessary to cause cell death suggesting a necrotic death similar to longer pulse exposures. These findings suggest that nanosecond pulses may be beneficial in applications that require selective elimination of specific cell types.

Cardiovascular reactivity as a mechanism linking child trauma to adolescent psychopathology.

PubMed

Heleniak, Charlotte; McLaughlin, Katie A; Ormel, Johan; Riese, Harriette

2016-10-01

Alterations in physiological reactivity to stress are argued to be central mechanisms linking adverse childhood environmental experiences to internalizing and externalizing psychopathology. Childhood trauma exposure may influence physiological reactivity to stress in distinct ways from other forms of childhood adversity. This study applied a novel theoretical model to investigate the impact of childhood trauma on cardiovascular stress reactivity - the biopsychosocial model of challenge and threat. This model suggests that inefficient cardiovascular responses to stress - a threat as opposed to challenge profile - are characterized by blunted cardiac output (CO) reactivity and increased vascular resistance. We examined whether childhood trauma exposure predicted an indicator of the threat profile of cardiovascular reactivity and whether such a pattern was associated with adolescent psychopathology in a population-representative sample of 488 adolescents (M=16.17years old, 49.2% boys) in the TRacking Adolescents' Individual Lives Survey (TRAILS). Exposure to trauma was associated with both internalizing and externalizing symptoms and a pattern of cardiovascular reactivity consistent with the threat profile, including blunted CO reactivity during a social stress task. Blunted CO reactivity, in turn, was positively associated with externalizing, but not internalizing symptoms and mediated the link between trauma and externalizing psychopathology. None of these associations varied by gender. The biopsychosocial model of challenge and threat provides a novel theoretical framework for understanding disruptions in physiological reactivity to stress following childhood trauma exposure, revealing a potential pathway linking such exposure with externalizing problems in adolescents. Copyright © 2016 Elsevier B.V. All rights reserved.

Cardiovascular reactivity as a mechanism linking child trauma to adolescent psychopathology

PubMed Central

Heleniak, Charlotte; McLaughlin, Katie A.; Ormel, Johan; Riese, Harriette

2016-01-01

Alterations in physiological reactivity to stress are argued to be central mechanisms linking adverse childhood environmental experiences to internalizing and externalizing psychopathology. Childhood trauma exposure may influence physiological reactivity to stress in distinct ways from other forms of childhood adversity. This study applied a novel theoretical model to investigate the impact of childhood trauma on cardiovascular stress reactivity – the biopsychosocial model of challenge and threat. This model suggests that inefficient cardiovascular responses to stress – a threat as opposed to challenge profile – are characterized by blunted cardiac output (CO) reactivity and increased vascular resistance. We examined whether childhood trauma exposure predicted an indicator of the threat profile of cardiovascular reactivity and whether such a pattern was associated with adolescent psychopathology in a population-representative sample of 488 adolescents (M = 16.17 years old, 49.2% boys) in the TRacking Adolescents’ Individual Lives Survey (TRAILS). Exposure to trauma was associated with both internalizing and externalizing symptoms and a pattern of cardiovascular reactivity consistent with the threat profile, including blunted CO reactivity during a social stress task. Blunted CO reactivity, in turn, was positively associated with externalizing, but not internalizing symptoms and mediated the link between trauma and externalizing psychopathology. None of these associations varied by gender. The biopsychosocial model of challenge and threat provides a novel theoretical framework for understanding disruptions in physiological reactivity to stress following childhood trauma exposure, revealing a potential pathway linking such exposure with externalizing problems in adolescents. PMID:27568327

Exposure of healthy subjects with emissions from a gas metal arc welding process: part 1--exposure technique and external exposure.

PubMed

Brand, P; Havlicek, P; Steiners, M; Holzinger, K; Reisgen, U; Kraus, T; Gube, M

2013-01-01

Studies concerning welding fume-related adverse health effects in welders are hampered by the heterogeneity of workplace situations, resulting in complex and non-standardized exposure conditions. In order to carry out welding fume exposure studies under controlled and standardized conditions, the Aachen Workplace Simulation Laboratory was developed. This laboratory consists of an emission room, in which welding fume is produced, and an exposure room in which human subjects are exposed to these fumes. Both rooms are connected by a ventilation system which allows the welding fume concentration to be regulated. Particle mass concentration was measured with a TEOM microbalance and the particle number-size distribution using a Grimm SMPS device. In a study, which is the subject of this paper, it has been shown that welding fume concentration can easily be regulated between 1 and about 3 mg m(-3). The chosen concentration can be kept constant for more than 8 h. However, transport of the particles from the emission room into the exposure room leads to a change in particle size distribution, which is probably due to coagulation of the fraction of smallest particles. The Aachen Workplace Simulation Laboratory is suitable for controlled exposure studies with human subjects.

Exogenous contamination of uranium in human scalp hair.

PubMed

Muikku, Maarit; Heikkinen, Tarja

2012-06-01

The use of human scalp hair as a bioindicator of occupational or environmental exposure has been the subject of some debate over the years. One problem is how to distinguish internal contamination from external contamination. In this study, possibility that elevated levels of natural uranium in human hair are partly due to the exogenously bound uranium from uranium-rich household water was tested. Hair samples from six adult volunteers were cut and then exposed externally to uranium by using washing water with highly elevated levels of natural uranium. After that, and before making the analysis using inductively coupled plasma mass spectrometry (ICP-MS), the samples were washed using two commonly used washing procedures in order to remove external contamination. No quantitative information was gained in the tests, but it was shown that the use of uranium-rich water when washing hair affects the uranium concentration in hair. Although the samples were cleaned according to widely used washing procedures before the analysis, the uranium concentrations in hair were about three orders of magnitude higher after the tests. The possibility of external contamination should be kept in mind, especially when considering hair as an excretion pathway for estimating internal dose.

Typologies of intimate partner violence-maternal parenting and children's externalizing problems: The moderating effect of the exposure to other forms of family violence.

PubMed

Lamela, Diogo; Jongenelen, Inês; Pinto, Ricardo; Levendosky, Alytia

2018-07-01

Typologies of IPV and parenting practices in mothers who experienced police-reported IPV remain surprisingly unexplored, in addition to how those typologies are linked with children's externalizing problems. Using data from 162 Portuguese mother-child dyads with a police or child protection services referral of IPV, this study aimed to: (a) identify IPV-parenting typologies; (b) test the associations between typologies and children's externalizing problems, and (c) examine the moderating effect of children's exposure to other forms of family violence in those associations. Using a person-centered approach, two IPV-parenting typologies were found: a spillover typology, with high levels of physical, psychological, and sexual violence and high levels of harsh and inconsistent parenting practices; and a compartmentalized typology, with high levels of physical, psychological, and sexual violence and lower ineffective parenting practices. Results also showed that externalizing symptoms (reported by mothers and teachers) were significantly lower in children of mothers in the compartmentalized typology compared to those in the spillover typology. Children's direct exposure to other forms of family violence moderated this association. Findings suggested that children with a high exposure to other forms of family violence showed the highest levels of externalizing problems when their mothers were classified into the spillover typology, and they exhibited the lowest levels of externalizing problems when their mothers were classified in the compartmentalized typology. Copyright © 2018 Elsevier Ltd. All rights reserved.

RECONSTRUCTION OF RADIATION DOSES IN A CASE-CONTROL STUDY OF THYROID CANCER FOLLOWING THE CHERNOBYL ACCIDENT

PubMed Central

Drozdovitch, Vladimir; Khrouch, Valeri; Maceika, Evaldas; Zvonova, Irina; Vlasov, Oleg; Bratilova, Angelica; Gavrilin, Yury; Goulko, Guennadi; Hoshi, Masaharu; Kesminiene, Ausrele; Shinkarev, Sergey; Tenet, Vanessa; Cardis, Elisabeth; Bouville, Andre

2010-01-01

A population-based case-control study of thyroid cancer was carried out in contaminated regions of Belarus and Russia among persons who were exposed during childhood and adolescence to fallout from the Chernobyl accident. For each study subject, individual thyroid doses were reconstructed for the following pathways of exposure: (1) intake of 131I via inhalation and ingestion; (2) intake of short-lived radioiodines (132I, 133I, and 135I) and radiotelluriums (131mTe, 132Te) via inhalation and ingestion; (3) external dose from radionuclides deposited on the ground; and (4) ingestion of 134Cs and 137Cs. A series of intercomparison exercises validated the models used for reconstruction of average doses to populations of specific age groups as well as of individual doses. Median thyroid doses from all factors for study subjects were estimated to be 0.37 and 0.034 Gy in Belarus and Russia, respectively. The highest individual thyroid doses among the subjects were 10.2 Gy in Belarus and 5.3 Gy in Russia. Iodine-131 intake was the main pathway for thyroid exposure. Estimated doses from short-lived radioiodines and radiotelluriums ranged up to 0.53 Gy. Reconstructed individual thyroid doses from external exposure ranged up to 0.1 Gy, while those from internal exposure due to ingested cesium did not exceed 0.05 Gy. The uncertainty of the reconstructed individual thyroid doses, characterized by the geometric standard deviation, varies from 1.7 to 4.0 with a median of 2.2. PMID:20539120

Retrospective dose assessment for the population living in areas of local fallout from the Semipalatinsk nuclear test site Part I: External exposure.

PubMed

Gordeev, Konstantin; Shinkarev, Sergey; Ilyin, Leonid; Bouville, André; Hoshi, Masaharu; Luckyanov, Nickolas; Simon, Steven L

2006-02-01

A short analysis of all 111 atmospheric events conducted at the Semipalatinsk Test Site (STS) in 1949-1962 with regard to significant off-site exposure (more than 5 mSv of the effective dose during the first year after the explosion) has been made. The analytical method used to assess external exposure to the residents living in settlements near the STS is described. This method makes use of the archival data on the radiological conditions, including the measurements of exposure rate. Special attention was given to the residents of Dolon and Kanonerka villages exposed mainly as a result of the first test, detonated on August 29, 1949. For the residents of those settlements born in 1935, the dose estimates calculated according to the analytical method, are compared to those derived from the thermoluminescence measurements in bricks and electron paramagnetic resonance measurements in teeth. The methods described in this paper were used for external dose assessment for the cohort members at an initial stage of an ongoing epidemiological study conducted by the U.S. National Cancer Institute in the Republic of Kazakhstan. Recently revised methods and estimates of external exposure for that cohort are given in another paper (Simon et al.) in this conference.

The effect of exposure to missile attacks on posttraumatic stress disorder symptoms as a function of perceived media control and locus of control.

PubMed

Hoffman, Yaakov S G; Shrira, Amit; Cohen-Fridel, Sara; Grossman, Ephraim S; Bodner, Ehud

2016-10-30

Exposure is one of the most robust predictors of post-traumatic stress disorder (PTSD) symptoms in warfare situations. Yet, while many are sensitive to exposure, others do not develop PTSD. In the current study, we address how perceived media control along with external locus of control moderate effects of exposure on PTSD symptoms among 1268 individuals exposed to missile attacks (mean age=36.97). We expected that the coupling of low perceived media control, whereby one feels poor control over media consumption (an inability to stop), especially when irrelevant and non-informative (e.g., involuntarily viewing the same terror incident shown repeatedly in a looped fashion) along with a self-perception of external locus of control, will render participants highly vulnerable to exposure. As expected, results suggest that effects of exposure on PTSD are not automatic, rather, the coupling of both low media control along with believing that life event are controlled by external factors exacerbates effects of exposure. These findings bear practical implications, as both media control and locus of control can be modified by therapeutic interventions, rendering one less vulnerable to the detrimental effects of traumatic exposure. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Regulated Forms of Cell Death in Fungi

PubMed Central

Gonçalves, A. Pedro; Heller, Jens; Daskalov, Asen; Videira, Arnaldo; Glass, N. Louise

2017-01-01

Cell death occurs in all domains of life. While some cells die in an uncontrolled way due to exposure to external cues, other cells die in a regulated manner as part of a genetically encoded developmental program. Like other eukaryotic species, fungi undergo programmed cell death (PCD) in response to various triggers. For example, exposure to external stress conditions can activate PCD pathways in fungi. Calcium redistribution between the extracellular space, the cytoplasm and intracellular storage organelles appears to be pivotal for this kind of cell death. PCD is also part of the fungal life cycle, in which it occurs during sexual and asexual reproduction, aging, and as part of development associated with infection in phytopathogenic fungi. Additionally, a fungal non-self-recognition mechanism termed heterokaryon incompatibility (HI) also involves PCD. Some of the molecular players mediating PCD during HI show remarkable similarities to major constituents involved in innate immunity in metazoans and plants. In this review we discuss recent research on fungal PCD mechanisms in comparison to more characterized mechanisms in metazoans. We highlight the role of PCD in fungi in response to exogenic compounds, fungal development and non-self-recognition processes and discuss identified intracellular signaling pathways and molecules that regulate fungal PCD. PMID:28983298

Using Retrieval Cues to Attenuate Return of Fear in Individuals With Public Speaking Anxiety.

PubMed

Shin, Ki Eun; Newman, Michelle G

2018-03-01

Even after successful exposure, relapse is not uncommon. Based on the retrieval model of fear extinction (e.g., Vervliet, Craske, & Hermans, 2013), return of fear can occur after exposure due to an elapse of time (spontaneous recovery) or change in context (contextual renewal). The use of external salient stimuli presented throughout extinction (i.e., retrieval cues [RCs]) has been suggested as a potential solution to this problem (Bouton, 2002). The current study examined whether RCs attenuated return of fear in individuals with public speaking anxiety. Sixty-five participants completed a brief exposure while presented with two RC stimuli aimed at a variety of senses (visual, tactile, olfactory, and auditory). Later, half the participants were tested for return of fear in a context different from the exposure context, and the other half in the same context. Half of each context group were presented with the same cues as in exposure, while the other half were not. Return of fear due to an elapse of time, change in context, and effects of RCs were evaluated on subjective, behavioral, and physiological measures of anxiety. Although contextual renewal was not observed, results supported effects of RCs in reducing spontaneous recovery on behavioral and physiological measures of anxiety. There was also evidence that participants who were reminded of feeling anxious during exposure by the RCs benefited more from using them at follow-up, whereas those who perceived the cues as comforting (safety signals) benefited less. Clinical implications of the findings are discussed. Copyright © 2017. Published by Elsevier Ltd.

10 CFR 835.203 - Combining internal and external equivalent doses.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Combining internal and external equivalent doses. 835.203 Section 835.203 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.203 Combining internal and external equivalent doses. (a) The total effective dose...

Reconstruction following traumatic partial amputation of the ear.

PubMed

Pearl, Robert A; Sabbagh, Walid

2011-02-01

Reconstruction following traumatic amputation of the external ear remains a unique challenge to the plastic surgeon. The authors report a series of ear reconstructions with autologous costal cartilage in patients following traumatic partial amputation of the ear. Technical points regarding the carving of the cartilage framework and methods of skin coverage are discussed. Fifty partial ear reconstructions with autologous costal cartilage were performed over a 4-year period. All patients had suffered previous traumatic amputation of part of the external auricle due to bite injuries (n = 36), road traffic accidents (n = 6), burns (n = 5), or torture (n = 3). A two-stage technique of reconstruction with autologous cartilage graft was used based on Nagata's adaptations of Brent's original technique. In nine cases, skin shortage or extensive scarring required preoperative tissue expansion (n = 4) or a temporoparietal fascial flap (n = 5) to provide adequate coverage of the cartilage framework. Forty-seven patients had a successful surgical outcome without complication. Two patients developed small areas of skin necrosis resulting in exposure of the cartilage framework. These healed with conservative management with minor loss of definition. One case of wound infection resulted in significant loss of definition of the construct, which required a further surgical procedure with additional costal cartilage graft. Reconstruction of the external ear with autologous costal cartilage following traumatic amputation can produce high-quality auricles consistently and is becoming the treatment of choice for such injuries, given access to a specialist center with exposure to a high volume of cases.

Genetic variation in GABRA2 moderates peer influence on externalizing behavior in adolescents

PubMed Central

Villafuerte, Sandra; Trucco, Elisa M; Heitzeg, Mary M; Burmeister, Margit; Zucker, Robert A

2014-01-01

Background Genetic predisposition and environmental influences are both important factors in the development of problematic behavior leading to substance use in adolescence. Involvement with delinquent peers also strongly predicts adolescent externalizing behavior. Several lines of evidence support a role of GABRA2 on externalizing behavior related to disinhibition. However, whether this genetic association is influenced by the environment such as peer behavior remains unknown. Methods We examined the moderating role of GABRA2 genetic variation on the socialization model of delinquent peer affiliation (at ages 12–14 years) on externalizing behavior (at ages 15–17 years) in the Michigan Longitudinal Study (MLS) adolescent sample. The sample consisted of 244 adolescents (75 females and 152 with at least one parent with a DSM-IV lifetime alcohol dependence/abuse diagnosis). Peer delinquent activity reported by the participant and teacher-reported adolescent externalizing behavior (Teacher Report Form (TRF) were assessed. Results No main effect of the GABRA2 SNP rs279826, which tags a large haplotype, on externalizing behavior was observed. However, there was a statistically reliable GABRA2 × peer delinquency interaction. The effect of peer delinquent involvement on externalizing scores and the rule breaking subscale is significantly stronger for those with the GG genotype compared to A-carriers, whereas there was no effect of genotype on externalizing in the absence of peer delinquent involvement. No interaction was observed for the aggression subscale. Conclusion Our results suggest that the genetic effect of GABRA2 on externalizing behavior, more specifically on rule breaking is, at least in part, due to its effect on susceptibility to environmental exposure (i.e., peer delinquency). PMID:25365806

Dose-response relationship between cumulative physical workload and osteoarthritis of the hip - a meta-analysis applying an external reference population for exposure assignment.

PubMed

Seidler, Andreas; Lüben, Laura; Hegewald, Janice; Bolm-Audorff, Ulrich; Bergmann, Annekatrin; Liebers, Falk; Ramdohr, Christina; Romero Starke, Karla; Freiberg, Alice; Unverzagt, Susanne

2018-06-01

There is consistent evidence from observational studies of an association between occupational lifting and carrying of heavy loads and the diagnosis of hip osteoarthritis. However, due to the heterogeneity of exposure estimates considered in single studies, a dose-response relationship between cumulative physical workload and hip osteoarthritis could not be determined so far. This study aimed to analyze the dose-response relationship between cumulative physical workload and hip osteoarthritis by replacing the exposure categories of the included studies with cumulative exposure values of an external reference population. Our meta-regression analysis was based on a recently conducted systematic review (Bergmann A, Bolm-Audorff U, Krone D, Seidler A, Liebers F, Haerting J, Freiberg A, Unverzagt S, Dtsch Arztebl Int 114:581-8, 2017). The main analysis of our meta-regression comprised six case-control studies for men and five for women. The population control subjects of a German multicentre case-control study (Seidler A, Bergmann A, Jäger M, Ellegast R, Ditchen D, Elsner G, Grifka J, Haerting J, Hofmann F, Linhardt O, Luttmann A, Michaelis M, Petereit-Haack G, Schumann B, Bolm-Audorff U, BMC Musculoskelet Disord 10:48, 2009) served as the reference population. Based on the sex-specific cumulative exposure percentiles of the reference population, we assigned exposure values to each category of the included studies using three different cumulative exposure parameters. To estimate the doubling dose (the amount of physical workload to double the risk of hip osteoarthritis) on the basis of all available case-control-studies, meta-regression analyses were conducted based on the linear association between exposure values of the reference population and the logarithm of reported odds ratios (ORs) from the included studies. In men, the risk to develop hip osteoarthritis was increased by an OR of 1.98 (95% CI 1.20-3.29) per 10,000 tons of weights ≥20 kg handled, 2.08 (95% CI 1.22-3.53) per 10,000 tons handled > 10 times per day and 8.64 (95% CI 1.87-39.91) per 10 6 operations. These estimations result in doubling dosages of 10,100 tons of weights ≥20 kg handled, 9500 tons ≥20 kg handled > 10 times per day and 321,400 operations of weights ≥20 kg. There was no linear association between manual handling of weights at work and risk to develop hip osteoarthritis in women. Under specific conditions, the application of an external reference population allows for the derivation of a dose-response relationship despite high exposure heterogeneities in the pooled studies.

Activity measurement and effective dose modelling of natural radionuclides in building material.

PubMed

Maringer, F J; Baumgartner, A; Rechberger, F; Seidel, C; Stietka, M

2013-11-01

In this paper the assessment of natural radionuclides' activity concentration in building materials, calibration requirements and related indoor exposure dose models is presented. Particular attention is turned to specific improvements in low-level gamma-ray spectrometry to determine the activity concentration of necessary natural radionuclides in building materials with adequate measurement uncertainties. Different approaches for the modelling of the effective dose indoor due to external radiation resulted from natural radionuclides in building material and results of actual building material assessments are shown. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sound Levels and Risk Perceptions of Music Students During Classes.

PubMed

Rodrigues, Matilde A; Amorim, Marta; Silva, Manuela V; Neves, Paula; Sousa, Aida; Inácio, Octávio

2015-01-01

It is well recognized that professional musicians are at risk of hearing damage due to the exposure to high sound pressure levels during music playing. However, it is important to recognize that the musicians' exposure may start early in the course of their training as students in the classroom and at home. Studies regarding sound exposure of music students and their hearing disorders are scarce and do not take into account important influencing variables. Therefore, this study aimed to describe sound level exposures of music students at different music styles, classes, and according to the instrument played. Further, this investigation attempted to analyze the perceptions of students in relation to exposure to loud music and consequent health risks, as well as to characterize preventive behaviors. The results showed that music students are exposed to high sound levels in the course of their academic activity. This exposure is potentiated by practice outside the school and other external activities. Differences were found between music style, instruments, and classes. Tinnitus, hyperacusis, diplacusis, and sound distortion were reported by the students. However, students were not entirely aware of the health risks related to exposure to high sound pressure levels. These findings reflect the importance of starting intervention in relation to noise risk reduction at an early stage, when musicians are commencing their activity as students.

Leukemia risk associated with chronic external exposure to ionizing radiation in a French cohort of nuclear workers.

PubMed

Metz-Flamant, C; Samson, E; Caër-Lorho, S; Acker, A; Laurier, D

2012-11-01

Leukemia is one of the earliest cancer effects observed after acute exposure to relatively high doses of ionizing radiation. Leukemia mortality after external exposure at low doses and low-dose rates has been investigated at the French Atomic Energy Commission (CEA) and Nuclear Fuel Company (AREVA NC) after an additional follow-up of 10 years. The cohort included radiation-monitored workers employed for at least one year during 1950-1994 at CEA or AREVA NC and followed during 1968-2004. Association between external exposure and leukemia mortality was estimated with excess relative risk (ERR) models and time-dependent modifying factors were investigated with time windows. The cohort included 36,769 workers, followed for an average of 28 years, among whom 73 leukemia deaths occurred. Among the workers with a positive recorded dose, the mean cumulative external dose was 21.7 mSv. Results under a 2-year lag assumption suggested that the risk of leukemia (except chronic lymphatic leukemia) increased significantly by 8% per 10 mSv. The magnitude of the association for myeloid leukemia was larger. The higher ERR/Sv for doses received 2-14 years earlier suggest that time since exposure modifies the effect. The ERR/Sv also appeared higher for doses received at exposure rates ≥20 mSv per year. These results are consistent with those found in other studies of nuclear workers. However, confidence intervals are still wide. Further analyses should be conducted in pooled cohorts of nuclear workers.

The role of maternal acceptance in the relation between community violence exposure and child functioning.

PubMed

Bailey, Beth Nordstrom; Hannigan, John H; Delaney-Black, Virginia; Covington, Chandice; Sokol, Robert J

2006-02-01

Children in the United States are exposed to considerable community violence that has been linked to child functioning. However, not all those exposed, experience negative outcomes. Recent research has focused on factors that "buffer" or protect children from negative consequences of violence exposure. The purpose of this investigation was to examine the potential buffering or moderating role of maternal acceptance in the relationship between community violence exposure and internalizing and externalizing problems. Subjects were 268 urban African American first graders. Community violence exposure was significantly related to symptoms of post-traumatic stress, but did not correlate with either internalizing or externalizing problems for all children, after control for demographics, maternal mental health, and general life stress. However, children's perceptions of maternal acceptance moderated the relationship between violence exposure and internalizing and externalizing problems which included being withdrawn, anxious-depressed, and demonstrating delinquent behavior. Children with the lowest levels of self-reported maternal acceptance were most impacted by community violence. In this sample of urban first graders, low levels of maternal acceptance placed children at greater risk for adverse outcomes associated with community violence exposure compared to moderate and high levels of maternal acceptance.

Inducible DNA-repair systems in yeast: competition for lesions.

PubMed

Mitchel, R E; Morrison, D P

1987-03-01

DNA lesions may be recognized and repaired by more than one DNA-repair process. If two repair systems with different error frequencies have overlapping lesion specificity and one or both is inducible, the resulting variable competition for the lesions can change the biological consequences of these lesions. This concept was demonstrated by observing mutation in yeast cells (Saccharomyces cerevisiae) exposed to combinations of mutagens under conditions which influenced the induction of error-free recombinational repair or error-prone repair. Total mutation frequency was reduced in a manner proportional to the dose of 60Co-gamma- or 254 nm UV radiation delivered prior to or subsequent to an MNNG exposure. Suppression was greater per unit radiation dose in cells gamma-irradiated in O2 as compared to N2. A rad3 (excision-repair) mutant gave results similar to wild-type but mutation in a rad52 (rec-) mutant exposed to MNNG was not suppressed by radiation. Protein-synthesis inhibition with heat shock or cycloheximide indicated that it was the mutation due to MNNG and not that due to radiation which had changed. These results indicate that MNNG lesions are recognized by both the recombinational repair system and the inducible error-prone system, but that gamma-radiation induction of error-free recombinational repair resulted in increased competition for the lesions, thereby reducing mutation. Similarly, gamma-radiation exposure resulted in a radiation dose-dependent reduction in mutation due to MNU, EMS, ENU and 8-MOP + UVA, but no reduction in mutation due to MMS. These results suggest that the number of mutational MMS lesions recognizable by the recombinational repair system must be very small relative to those produced by the other agents. MNNG induction of the inducible error-prone systems however, did not alter mutation frequencies due to ENU or MMS exposure but, in contrast to radiation, increased the mutagenic effectiveness of EMS. These experiments demonstrate that in this lower eukaryote, mutagen exposure does not necessarily result in a fixed risk of mutation, but that the risk can be markedly influenced by a variety of external stimuli including heat shock or exposure to other mutagens.

Adaptive response studies may help choose astronauts for long-term space travel.

PubMed

Mortazavi, S M; Cameron, J R; Niroomand-rad, A

2003-01-01

Long-term manned exploratory missions are planned for the future. Exposure to high-energy neutrons, protons and high charge and energy particles during a deep space mission, needs protection against the detrimental effects of space radiation. It has been suggested that exposure to unpredictable extremely large solar particle events would kill the astronauts without massive shielding. To reduce this risk to astronauts and to minimize the need for shielding, astronauts with highest significant adaptive responses should be chosen. It has been demonstrated that some humans living in very high natural radiation areas have acquired high adaptive responses to external radiation. Therefore, we suggest that for a deep space mission the adaptive response of all potential crew members be measured and only those with high adaptive response be chosen. We also proclaim that chronic exposure to elevated levels of radiation can considerably decrease radiation susceptibility and better protect astronauts against the unpredictable exposure to sudden and dramatic increase in flux due to solar flares and coronal mass ejections. c2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Ventilation noise and its effects on annoyance and performance

NASA Astrophysics Data System (ADS)

Landstrom, Ulf

2004-05-01

In almost every room environment, ventilation acts as a more or less prominent part of the noise exposure. The contribution to the overall sound environment is a question not only of the way in which the ventilation system itself functions, but also a question of the prominence of other contemporary sound sources such as speech, equipment, machines, and external noises. Hazardous effects due to ventilation noise are most prominent in offices, hospitals, control rooms, classrooms, conference rooms, and other types of silent areas. The effects evoked by ventilation noise have also been found to be related to the type of activity being conducted. Annoyance and performance thus not only seemed to be linked to the physical character of exposure, i.e., noise level, frequency characteristics, and length of exposure, but also mental and manual activity, complexity, and monotony of the work. The effects can be described in terms of annoyance, discomfort, and fatigue, with consequences on performance and increased mental load. The silent areas where ventilation noise may be most frequently experienced are often synonymous with areas and activities most sensitive to the exposure.

Childhood problem behavior and parental divorce: evidence for gene-environment interaction.

PubMed

Robbers, Sylvana; van Oort, Floor; Huizink, Anja; Verhulst, Frank; van Beijsterveldt, Catharina; Boomsma, Dorret; Bartels, Meike

2012-10-01

The importance of genetic and environmental influences on children's behavioral and emotional problems may vary as a function of environmental exposure. We previously reported that 12-year-olds with divorced parents showed more internalizing and externalizing problems than children with married parents, and that externalizing problems in girls precede and predict later parental divorce. The aim of the current study was to investigate as to whether genetic and environmental influences on internalizing and externalizing problems were different for children from divorced versus non-divorced families. Maternal ratings on internalizing and externalizing problems were collected with the Child Behavior Checklist in 4,592 twin pairs at ages 3 and 12 years, of whom 367 pairs had experienced a parental divorce between these ages. Variance in internalizing and externalizing problems at ages 3 and 12 was analyzed with biometric models in which additive genetic and environmental effects were allowed to depend on parental divorce and sex. A difference in the contribution of genetic and environmental influences between divorced and non-divorced groups would constitute evidence for gene-environment interaction. For both pre- and post-divorce internalizing and externalizing problems, the total variances were larger for children from divorced families, which was mainly due to higher environmental variances. As a consequence, heritabilities were lower for children from divorced families, and the relative contributions of environmental influences were higher. Environmental influences become more important in explaining variation in children's problem behaviors in the context of parental divorce.

Evaluation of occupational exposure to naturally occurring radioactive materials in the Iranian ceramics industry.

PubMed

Fathabadi, N; Farahani, M V; Amani, S; Moradi, M; Haddadi, B

2011-06-01

Zircon contains small amounts of uranium, thorium and radium in its crystalline structure. The ceramic industry is one of the major consumers of zirconium compounds that are used as an ingredient at ∼10-20 % by weight in glaze. In this study, seven different ceramic factories have been investigated regarding the presence of radioactive elements with focus on natural radioactivity. The overall objective of this investigation is to provide information regarding the radiation exposure to workers in the ceramic industry due to naturally occurring radioactive materials. This objective is met by collecting existing radiological data specific to glaze production and generating new data from sampling activities. The sampling effort involves the whole process of glaze production. External exposures are monitored using a portable gamma-ray spectrometer and environmental thermoluminescence dosimeters, by placing them for 6 months in some workplaces. Internal routes of exposure (mainly inhalation) are studied using air sampling, and gross alpha and beta counting. Measurement of radon gas and its progeny is performed by continuous radon gas monitors that use pulse ionisation chambers. Natural radioactivity due to the presence of ²³⁸U, ²³²Th and ⁴⁰K in zirconium compounds, glazes and other samples is measured by a gamma-ray spectrometry system with a high-purity germanium detector. The average concentrations of ²³⁸U and ²³²Th observed in the zirconium compounds are >3300 and >550 Bq kg⁻¹, respectively. The specific activities of other samples are much lower than in zirconium compounds. The annual effective dose from external radiation had a mean value of ∼0.13 mSv y⁻¹. Dust sampling revealed the greatest values in the process at the powdering site and hand weighing places. In these plants, the annual average effective dose from inhalation of long-lived airborne radionuclides was 0.226 mSv. ²²²Rn gas concentrations in the glaze production plant and storage warehouse were found to range from 10 to 213 Bq m⁻³. In this study, the estimated annual effective doses to exposed workers were <1 mSv y⁻¹.

Who initiates and organises situations for work-related alcohol use? The WIRUS culture study.

PubMed

Nordaune, Kristin; Skarpaas, Lisebet S; Sagvaag, Hildegunn; Haveraaen, Lise; Rimstad, Silje; Kinn, Liv G; Aas, Randi W

2017-12-01

Alcohol is one of the leading causes of ill health and premature death in the world. Several studies indicate that working life might influence employees' alcohol consumption and drinking patterns. The aim of this study was to explore work-related drinking situations, with a special focus on answering who initiates and organises these situations. Data were collected through semi-structured group interviews in six Norwegian companies from the private ( n=4) and public sectors ( n=2), employing a total of 3850 employees. The informants ( n=43) were representatives from management and local unions, safety officers, advisers from the social insurance office and human-resource personnel, health, safety and environment personnel, and members from the occupational environment committee. Both qualitative and quantitative content analyses were applied in the analyses of the material. Three different initiators and organisers were discovered: the employer, employees and external organisers. External organisers included customers, suppliers, collaborators, sponsors, subcontractors, different unions and employers' organisations. The employer organised more than half of the situations; external organisers were responsible for more than a quarter. The differences between companies were mostly due to the extent of external organisers. The employer initiates and organises most situations for work-related alcohol use. However, exposure to such situations seems to depend on how many external relations the company has. These aspects should be taken into account when workplace health-promotion initiatives are planned.

Comparative techniques of medial rectus muscle retraction for endoscopic exposure of the medial intraconal space.

PubMed

Lin, Giant C; Freitag, Suzanne K; Kocharyan, Armine; Yoon, Michael K; Lefebvre, Daniel R; Bleier, Benjamin S

2016-05-01

The medial rectus muscle (MRM) is the medial boundary to the intraconal space of the orbit, and retraction of the MRM is oftentimes necessary for endoscopic removal of intraconal tumors, e.g., orbital hemangioma. We evaluated each of the reported methods of MRM retraction for endoscopic orbital surgery and quantified the degree of intraconal exposure conferred by each method. Eight orbits from four cadaver heads were dissected. In each orbit, medial orbital decompression was performed and the MRM was retracted by using four previously described techniques: (1) external MRM retraction at the globe insertion point by using vessel loop (external group), (2) transseptal MRM retraction by using vessel loop (transseptal group), (3) transchoanal retraction of the MRM by using vessel loop (choanal group), and (4) transseptal four-handed technique by using double ball retraction by a second surgeon (transseptal double ball group). The length, height, and area of exposure of the medial intraconal space were quantified and compared. The average ± standard deviation (SD) anterior-posterior exposures for the external group, transseptal group, and transseptal double ball group were 17.51 ± 3.39 mm, 16.59 ± 4.16 mm, and 18.0 ± 15.25 mm, respectively. The choanal group provided significantly less exposure (12.39 ± 3.44 mm, p = 0.049) than the other groups. The average ± SD vertical exposures for the transseptal group, choanal group, and transseptal double ball group were 12.53 ± 4.38 mm, 13.05 ± 5.86 mm, and 13.57 ± 3.74 mm, respectively. The external group provided significantly less exposure (4.51 ± 1.56 mm, p = 0.0072) than the other groups. The transseptal and transseptal double ball groups provided the greatest total access by surface area (58.88 ± 26.96 mm(2) and 62.94 ± 34.74 mm(2), respectively) compared with the external and choanal groups (34.82 ± 23.37 mm(2) and 43.10 ± 23.68 mm(2), respectively). Although the transseptal trajectory of MRM retraction was optimal, the difference in total area of exposure between the static vessel loop retraction and the dynamic, four-handed technique with double ball instrument retraction was not significant. Of note, the exposure provided by the choanal technique required the surgeon to work both above and below the muscle. Retraction of the MRM toward the choanae provided the least length of exposure, and external retraction exposed the least height and total area. Transseptal MRM retraction was most favorable and provided the largest endoscopic corridor to the medial intraconal space. A four-handed approach for endoscopic intraconal surgery of the orbit may offer advantages in dynamic adjustments in retraction.

Effect of Solar Exposure on the Atomic Oxygen Erosion of Hubble Space Telescope Aluminized-Teflon Thermal Shields

NASA Astrophysics Data System (ADS)

Guo, Aobo; Ashmead, Claire C.; de Groh, Kim K.; Sechkar, Edward A.

When exposed to low Earth orbit (LEO) environment, external spacecraft materials degrade due to radiation, thermal cycling, micrometeoroid and debris impacts, and interaction with atomic oxygen (AO). Collisions between AO and spacecraft can result in oxidation of external spacecraft surface materials, which can lead to erosion and severe structural and/or optical properties deterioration. It is therefore essential to understand the AO erosion yield (Ey), the volume loss per incident oxygen atom (cm3/atom) of polymers to assure durability of spacecraft materials. The objective of this study was to determine whether solar radiation exposure can increase the rate of AO erosion of polymers in LEO. The material studied was a section of aluminized-Teflon® fluorinated ethylene propylene (Al-FEP) thermal shield exposed to space on the Hubble Space Telescope (HST) for 8.25 years. Retrieved samples were sectioned from the circular thermal shield and exposed to ground laboratory thermal energy AO. The results indicate that the average Ey of the solar facing HST Al-FEP was 1.9 × 10-24 cm3/atom, while the average Ey of the anti-solar HST Al-FEP was 1.5 × 10-24 cm3/atom. The Ey of the pristine samples was 1.6 to 1.7 × 10-24 cm3/atom. These results indicate that solar exposure affects the post-flight erosion rate of FEP in a plasma asher. Therefore, it likely affects the erosion rate while in LEO.

Effect of Solar Exposure on the Atomic Oxygen Erosion of Hubble Space Telescope Aluminized-Teflon Thermal Shields

NASA Technical Reports Server (NTRS)

Guo, Aobo; Ashmead, Claire C.; deGroh, Kim K.

2012-01-01

When exposed to low Earth orbital (LEO) environment, external spacecraft materials degrade due to radiation, thermal cycling, micrometeoroid and debris impacts, and atomic oxygen (AO) interaction. Collisions between AO and spacecraft can result in oxidation of external spacecraft surface materials, which can lead to erosion and severe structural and/or optical property deterioration. It is therefore essential to understand the AO erosion yield (Ey), the volume loss per incident oxygen atom (cu cm/atom), of polymers to assure durability of spacecraft materials. The objective of this study was to determine whether solar radiation exposure can increase the rate of AO erosion of polymers in LEO. The material studied was a section of aluminized-Teflon (DuPont) fluorinated ethylene propylene (Al-FEP) thermal shield exposed to space on the Hubble Space Telescope (HST) for 8.25 years. Retrieved samples were sectioned from the circular thermal shield and exposed to ground laboratory thermal energy AO. The results indicate that the average Ey of the solar facing HST Al-FEP was 1.9 10(exp -24)cu cm/atom, while the average Ey of the anti-solar HST Al-FEP was 1.5 10(exp -24)cu cm/atom. The Ey of the pristine samples was 1.6- 1.7 10(exp -24)cu cm/atom. These results indicate that solar exposure affects the post-flight erosion rate of FEP in a plasma asher. Therefore, it likely affects the erosion rate while in LEO.

Do hunger and exposure to food affect scores on a measure of hedonic hunger? An experimental study.

PubMed

Witt, Ashley A; Raggio, Greer A; Butryn, Meghan L; Lowe, Michael R

2014-03-01

Research suggests that visceral bodily states, such as hunger, can affect participants' responses on self-report measures of eating behavior. The present study evaluated the influence of hunger and exposure to palatable food on self-reported hedonic appetite, measured using the Power of Food Scale (PFS). A secondary aim was to evaluate the effects of these manipulations on self-reported external eating and disinhibition. Participants (N=67) ate a standardized meal followed by a 4-h fast. Participants were randomized to one of four groups (Fasted/Food Absence, Fasted/Food Exposure, Fed/Food Absence, or Fed/Food Exposure). In Phase I of the experiment (Hunger Manipulation), participants randomized to the "Fed" group drank a protein shake, while those in the "Fasted" group did not receive a shake. In Phase II (Palatable Food Exposure), participants in the "Food Exposure" group were visually exposed to palatable food items, while "Food Absence" participants were not. All participants completed the PFS, Dutch Eating Behavior Questionnaire External Eating subscale, and the Disinhibition subscale from the Eating Inventory during Phase II. Results showed no significant main or interactive effects of Hunger condition or Food Exposure condition on PFS, External Eating, or Disinhibition scores (all p's<.33). All effect sizes were small (partial etas squared ⩽.015). Manipulation checks confirmed that the intended hunger and exposure interventions were successful. Results suggest that relatively short fasting periods (e.g., 4h) analogous to typical breaks between meals are not associated with changes in scores on the PFS, External Eating, or Disinhibition scales. Hedonic hunger, at least as measured by the PFS, may represent a relatively stable construct that is not substantially affected by daily variations in hunger. In addition, individual differences in exposure to food in the immediate environment are unlikely to confound research using these measures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of Prenatal Cocaine Exposure on Early Sexual Behavior: Gender Difference in Externalizing Behavior as a Mediator

PubMed Central

Min, Meeyoung O.; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T.

2015-01-01

Background Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Methods Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year old adolescents participated in a prospective longitudinal study. Adolescents’ sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Results Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI= 1.2 – 4.1, p < .01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4 – 4.7, p < .002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. Conclusions PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. PMID:26088698

Effects of prenatal cocaine exposure on early sexual behavior: Gender difference in externalizing behavior as a mediator.

PubMed

Min, Meeyoung O; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T

2015-08-01

Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year-old adolescents participated in a prospective longitudinal study. Adolescents' sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI=1.2-4.1, p<.01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4-4.7, p<.002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Spatial and Temporal Variations in Arsenic Exposure via Drinking-water in Northern Argentina

PubMed Central

Concha, Gabriela; Nermell, Barbro

2006-01-01

This study evaluated the spatial, temporal and inter-individual variations in exposure to arsenic via drinking-water in Northern Argentina, based on measurements of arsenic in water, urine, and hair. Arsenic concentrations in drinking-water varied markedly among locations, from <1 to about 200 μg/L. Over a 10-year period, water from the same source in San Antonio de los Cobres fluctuated within 140 and 220 μg/L, with no trend of decreasing concentration. Arsenic concentrations in women's urine (3–900 μg/L, specific weight 1.018 g/mL) highly correlated with concentrations in water on a group level, but showed marked variations between individuals. Arsenic concentrations in hair (range 20–1,500 μg/kg) rather poorly correlated with urinary arsenic, possibly due to external contamination. Thus, arsenic concentration in urine seems to be a better marker of individual arsenic exposure than concentrations in drinking-water and hair. PMID:17366773

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

The role of callous/unemotional traits in mediating the association between animal abuse exposure and behavior problems among children exposed to intimate partner violence.

PubMed

McDonald, Shelby Elaine; Dmitrieva, Julia; Shin, Sunny; Hitti, Stephanie A; Graham-Bermann, Sandra A; Ascione, Frank R; Williams, James Herbert

2017-10-01

Children exposed to intimate partner violence are at increased risk for concomitant exposure to maltreatment of companion animals. There is emerging evidence that childhood exposure to maltreatment of companion animals is associated with psychopathology in childhood and adulthood. However, few studies have explored developmental factors that might help to explain pathways from animal maltreatment exposure to children's maladjustment. The present study addresses this gap in the literature by examining relations between children's exposure to animal maltreatment, callous/unemotional traits (i.e., callousness, uncaring traits, and unemotional traits), and externalizing and internalizing behavior problems. A sample of 291 ethnically diverse children (55% Latino or Hispanic) between the ages of 7 and 12 was recruited from community-based domestic violence services. A meditational path model indicated that child exposure to animal maltreatment was associated with callousness (β=0.14), which in turn was associated with greater internalizing (β=0.32) and externalizing problems (β=0.47). The effect of animal maltreatment exposure on externalizing problems was mediated through callousness. Results suggest that callous/unemotional traits are a potential mechanism through which childhood exposure to animal maltreatment influences subsequent behavior problems. Future research is needed to evaluate the extent to which exposure to animal maltreatment affects children's adjustment over time in the context of other co-occurring adverse childhood experiences. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Roles of Family and Teacher Support in Moderating and Mediating Externalized and Internalized Outcomes of Exposure to Community Violence Among Arab and Jewish Adolescents in Israel.

PubMed

Haj-Yahia, Muhammad M; Leshem, Becky; Guterman, Neil B

2018-02-01

The study examined family and teacher support as factors that can protect adolescents from internalized and externalized problems after exposure to community violence (ECV). Self-administered questionnaires were filled out by a sample of 1,832 Arab and Jewish Israeli high school students. The Arab adolescents reported significantly higher levels of community violence victimization, internalized problems, externalized problems, family support, and teacher support than the Jewish adolescents. The girls reported higher levels of internalized problems, and the boys reported higher levels of externalized problems. ECV predicted high levels of internalized and externalized problems, family support predicted low levels of internalized and externalized problems, and teacher support had no predictive role. Path analysis confirmed the significance of the relationships between ECV effects, support variables, and gender. The limitations of the study and implications of the findings for future research and for the development of family care and family intervention programs are discussed.

ESTIMATES OF RADIATION DOSES TO THE SKIN FOR PEOPLE CAMPED AT WALLATINNA DURING THE UK TOTEM 1 ATOMIC WEAPONS TEST.

PubMed

Williams, G A; O'Brien, R S; Grzechnik, M; Wise, K N

2017-04-28

A group of Aboriginal people was camped at Wallatinna in South Australia, ~170 km downwind from Emu Field, where an atomic test (the Totem 1 test) was carried out at 07.00 on 15 October 1953 local time (21.30 on 14 October 1953 GMT (Greenwich Mean Time)). They left the camp ~24 hours later. These people stated that a phenomenon that has become known as a 'black mist' rolled through their camp site ~5 hours after detonation and that some of them subsequently became sick, displaying skin reddening and nausea. They feared that the sickness was a result of exposure to high levels of radiation. The purpose of this paper is to determine if these people could have received ionising radiation doses high enough to cause the symptoms displayed. The methodology used for the dose estimates is described in the paper. The exposure modes considered were external exposure due to the passage of a contaminated plume over the camp site, inhalation of material from this plume, external exposure from material deposited on the ground as the plume passed, and consumption of contaminated food and water. The contaminants considered in the airborne cloud and the ground plume were fission products and unburnt plutonium from the nuclear detonation, and neutron activation products caused by vaporisation of the tower used to position the weapon. The source was approximated by a line source. An upper estimate of the effective doses received is ~4 mSv, which is well below the level at which acute radiation effects are observed. This estimate is consistent with earlier assessments, which did not consider inhalation of the contribution from neutron activation products. © Crown copyright 2016.

Age at exposure to ionising radiation and cancer mortality among Hanford workers: follow up through 1994

PubMed Central

Wing, S; Richardson, D

2005-01-01

Background: Studies of workers at the plutonium production factory in Hanford, WA have led to conflicting conclusions about the role of age at exposure as a modifier of associations between ionising radiation and cancer. Aims: To evaluate the influence of age at exposure on radiation risk estimates in an updated follow up of Hanford workers. Methods: A cohort of 26 389 workers hired between 1944 and 1978 was followed through 1994 to ascertain vital status and causes of death. External radiation dose estimates were derived from personal dosimeters. Poisson regression was used to estimate associations between mortality and cumulative external radiation dose at all ages, and in specific age ranges. Results: A total of 8153 deaths were identified, 2265 of which included cancer as an underlying or contributory cause. Estimates of the excess relative risk per Sievert (ERR/Sv) for cumulative radiation doses at all ages combined were negative for all cause and leukaemia and positive for all cancer and lung cancer. Cumulative doses accrued at ages below 35, 35–44, and 45–54 showed little association with mortality. For cumulative dose accrued at ages 55 and above (10 year lag), the estimated ERR/Sv for all cancers was 3.24 (90% CI: 0.80 to 6.17), primarily due to an association with lung cancer (ERR/Sv: 9.05, 90% CI: 2.96 to 17.92). Conclusions: Associations between radiation and cancer mortality in this cohort are primarily a function of doses at older ages and deaths from lung cancer. The association of older age radiation exposures and cancer mortality is similar to observations from several other occupational studies. PMID:15961623

Mortality of employees of the Atomic Weapons Establishment, 1951-82.

PubMed Central

Beral, V.; Fraser, P.; Carpenter, L.; Booth, M.; Brown, A.; Rose, G.

1988-01-01

A total of 22,552 workers employed by the Atomic Weapons Establishment between 1951 and 1982 were followed up for an average of 18.6 years. Of the 3115 who died, 865 (28%) died of cancer. Mortality was 23% lower than the national average for all causes of death and 18% lower for cancer. These low rates were consistent with the findings in other workforces in the nuclear industry and reflect, at least in part, the selection of healthy people to work in the industry and the disproportionate recruitment of people from the higher social classes. At some time during their employment 9389 (42%) of the workers were monitored for exposure to radiation, the average cumulative whole body exposure to external radiation being 7.8 mSv. Their mortality was generally similar to that of other employees, even when exposures were lagged by 10 years. The rate ratio after a 10 year lag in workers with a radiation record compared with other workers was 1.01 (95% confidence interval 0.92 to 1.10) for all causes of death and 1.06 (0.89 to 1.27) for all malignant neoplasms. The only significant differences were for prostatic cancer (rate ratio 2.23; 95% confidence interval 1.13 to 4.40) and for cancers of ill defined and secondary sites (rate ratio 2.37; 1.23 to 4.56). Cancers of lymphatic and haemopoietic tissues were notable for their low occurrence in the study population, with only four deaths from leukaemia and two from multiple myeloma in workers with a radiation record, 9.16 and 3.55 deaths respectively being expected on the basis of national rates. Among workers who had a radiation record 3742 (40%) were also monitored for possible internal exposure to plutonium, 3044 (32%) to uranium, 1562 (17%) to tritium, 638 (7%) to polonium, and 281 (3%) to actinium. In these workers mortality from malignant neoplasms as a whole was not increased, but after a 10 year lag death rates from prostatic and renal cancers were generally more than twice the national average, these excesses arising in a small group of workers monitored for exposure to multiple radionuclides. Though mortality from lung cancer in workers monitored for exposure to plutonium was below the national average, it was some two thirds higher than in other radiation workers, the excess being of borderline statistical significance. Mortality from malignant neoplasms as a whole showed a weak and non-significant increasing trend with increasing level of cumulative whole body exposure to external radiation. When the exposures were lagged by 10 years the trend became stronger and significant, the estimated increase in relative risk per 10 mSv being 7.6% (95% confidence interval 0.4% to 15.3%). This trend was confined almost entirely to workers who were also monitored for exposure to radionuclides (p<0.001), the main contributions coming from lung cancer and prostatic cancer. Exposures of the lung and prostate from internal sources of radiation were not quantified, except for the contribution from tritium. It was therefore not possible to assess the extent to which the associations were due to internally deposited radionuclides rather than external exposure. The finding for prostatic cancer taken in conjunction with the results of other studies suggest a specific occupational hazard in a small group of workers in the nuclear industry who had comparatively high exposures to external radiation and who were also monitored for internal exposure to multiple radionuclides. Research is needed to discover whether any of the radionuclides and other substances concerned are concentrated in the prostate. The occurrence of lung cancer in this workforce requires further investigation taking into account smoking habits and tissue doses from inhaled radionuclides. PMID:3142540

Computational fluid dynamics modeling of Bacillus anthracis spore deposition in rabbit and human respiratory airways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kabilan, S.; Suffield, S. R.; Recknagle, K. P.

Three-dimensional computational fluid dynamics and Lagrangian particle deposition models were developed to compare the deposition of aerosolized Bacillus anthracis spores in the respiratory airways of a human with that of the rabbit, a species commonly used in the study of anthrax disease. The respiratory airway geometries for each species were derived respectively from computed tomography (CT) and µCT images. Both models encompassed airways that extended from the external nose to the lung with a total of 272 outlets in the human model and 2878 outlets in the rabbit model. All simulations of spore deposition were conducted under transient, inhalation–exhalation breathingmore » conditions using average species-specific minute volumes. Two different exposure scenarios were modeled in the rabbit based upon experimental inhalation studies. For comparison, human simulations were conducted at the highest exposure concentration used during the rabbit experimental exposures. Results demonstrated that regional spore deposition patterns were sensitive to airway geometry and ventilation profiles. Due to the complex airway geometries in the rabbit nose, higher spore deposition efficiency was predicted in the nasal sinus compared to the human at the same air concentration of anthrax spores. In contrast, higher spore deposition was predicted in the lower conducting airways of the human compared to the rabbit lung due to differences in airway branching pattern. This information can be used to refine published and ongoing biokinetic models of inhalation anthrax spore exposures, which currently estimate deposited spore concentrations based solely upon exposure concentrations and inhaled doses that do not factor in species-specific anatomy and physiology for deposition.« less

Estimation of annual occupational effective doses from external ionizing radiation at medical institutions in Kenya

NASA Astrophysics Data System (ADS)

Korir, Geoffrey; Wambani, Jeska; Korir, Ian

2011-04-01

This study details the distribution and trends of doses due to occupational radiation exposure among radiation workers from participating medical institutions in Kenya, where monthly dose measurements were collected for a period of one year ranging from January to December in 2007. A total of 367 medical radiation workers were monitored using thermoluminescent dosemeters. They included radiologists (27%), oncologists (2%), dentists (4%), Physicists (5%), technologists (45%), nurses (4%), film processor technicians (3%), auxiliary staff (4%), and radiology office staff (5%). The average annual effective dose of all categories of staff was found to range from 1.19 to 2.52 mSv. This study formed the initiation stage of wider, comprehensive and more frequent monitoring of occupational radiation exposures and long-term investigations into its accumulation patterns in our country.

Developmental timing and continuity of exposure to interparental violence and externalizing behavior as prospective predictors of dating violence.

PubMed

Narayan, Angela J; Englund, Michelle M; Egeland, Byron

2013-11-01

This study investigated the prospective pathways of children's exposure to interparental violence (EIPV) in early and middle childhood and externalizing behavior in middle childhood and adolescence as developmental predictors of dating violence perpetration and victimization at ages 23 and 26 years. Participants (N = 168) were drawn from a longitudinal study of low-income families. Path analyses examined whether timing or continuity of EIPV predicted dating violence and whether timing or continuity of externalizing behavior mediated these pathways. Results indicated that EIPV in early childhood directly predicted perpetration and victimization at age 23. There were significant indirect effects from EIPV to dating violence through externalizing behavior in adolescence and life stress at age 23. Independent of EIPV, externalizing behavior in middle childhood also predicted dating violence through externalizing behavior in adolescence and life stress at age 23, but this pathway stemmed from maltreatment. These results highlight that the timing of EIPV and both the timing and the continuity of externalizing behavior are critical risks for the intergenerational transmission of dating violence. The findings support a developmental perspective that negative early experiences and children's externalizing behavior are powerful influences for dating violence in early adulthood.

Developmental Timing and Continuity of Exposure to Interparental Violence and Externalizing Behavior as Prospective Predictors of Dating Violence

PubMed Central

Narayan, Angela J.; Englund, Michelle M.; Egeland, Byron

2014-01-01

This study investigated the prospective pathways of children's exposure to interparental violence (EIPV) in early and middle childhood and externalizing behavior in middle childhood and adolescence as developmental predictors of dating violence perpetration and victimization at ages 23 and 26 years. Participants (N = 168) were drawn from a longitudinal study of low-income families. Path analyses examined whether timing or continuity of EIPV predicted dating violence and whether timing or continuity of externalizing behavior mediated these pathways. Results indicated that EIPV in early childhood directly predicted perpetration and victimization at age 23. There were significant indirect effects from EIPV to dating violence through externalizing behavior in adolescence and life stress at age 23. Independent of EIPV, externalizing behavior in middle childhood also predicted dating violence through externalizing behavior in adolescence and life stress at age 23, but this pathway stemmed from maltreatment. These results highlight that the timing of EIPV and both the timing and continuity of externalizing behavior are critical risks for the intergenerational transmission of dating violence. Findings support a developmental perspective that negative early experiences and children's externalizing behavior are powerful influences for dating violence in early adulthood. PMID:24229543

Radioactive contamination of the environment and its effects on livestock and food of animal origin (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kreuzer, W.

External and internal natural radiation exposure seems to be relatively and absolutely higher in livestock, mainly in herbivores, than in man. The artificial internal and external radiation exposure hardly exists in animals, even not in the vicinity of nuclear reactors. The external radiation exposure resulting from the radionuclides of the fallout of nuclear weapon experiments was negligibly small in Central Europe. The internal radiation exposure after intake of radionuclides with food of animal origin and their accumulation in the organism of the consumer is important. Milk and dairy products may contain considerable amounts of/sup 131/I, /sup 137/Cs, and /sup 90/Sr.more » In meat, /sup 137/Cs-contaminations were found sporadically that were higher than the permissible maximal dose. In total, the artificial radiation exposure did not yet reach the dimensions of the natural radiation exposure, neither in livestock nor in men, even not in reindeers or their breeders in Lapland, where the extreme /sup 137/Cs-contamination of the lichen causes high /sup 137/Csactivity, both in reindeers and in reindeer breeders who live almost exclusively on meat, blood, and milk of the animals. The radioactive contamination of livestock and food of animal origin may cause concern in case of a crisis or emengency. (GE)« less

Media content and externalizing behaviors in Latino toddlers.

PubMed

Tomopoulos, Suzy; Dreyer, Benard P; Valdez, Purnima; Flynn, Virginia; Foley, Gilbert; Berkule, Samantha B; Mendelsohn, Alan L

2007-01-01

There has been limited study of the association between media exposure and behavior in children younger than age 3 years. We sought to study this association in toddlers and determine whether the association varied depending on media content. We carried out a secondary analysis of a cohort of Latino mother-infant dyads followed from birth to 33 months. We assessed media exposure at 21 and 33 months with a 24-hour recall diary that included information about the duration and content of each program watched. Behavior was assessed at 33 months by the Child Behavior Checklist. This analysis included 99 dyads. Results from multiple logistic regression analyses indicated associations of child behavior outcomes with 21-month total media exposure and both 21-month and 33-month exposure to noneducational young child media such as cartoons, after adjusting for maternal education, country of origin, and depressive symptoms, participation in a parenting program, and difficult child temperament. Media exposure has most consistent associations with aggressive behavior and externalizing problems. Media exposure was associated with externalizing behavior in Latino toddlers, with the strongest association for media oriented toward young children but without educational content. This finding has importance for both parents of young children and pediatricians as they provide anticipatory guidance.

Years of Life Lost Due to External Causes of Death in the Lodz Province, Poland

PubMed Central

Pikala, Malgorzata; Bryla, Marek; Bryla, Pawel; Maniecka-Bryla, Irena

2014-01-01

Background The aim of the study is the analysis of years of life lost due to external causes of death, particularly due to traffic accidents and suicides. Materials and Methods The study material includes a database containing information gathered from 376,281 death certificates of inhabitants of the Lodz province who died between 1999 and 2010. The Lodz province is characterized by the highest mortality rates in Poland. The SEYLLp (Standard Expected Years of Life Lost per living person) and the SEYLLd (per death) indices were used to determine years of life lost. Joinpoint models were used to analyze time trends. Results In 2010, deaths due to external causes constituted 6.0% of the total number of deaths. The standardized death rate (SDR) due to external causes was 110.0 per 100,000 males and was five times higher than for females (22.0 per 100,000 females). In 2010, the SEYLLp due to external causes was 3746 per 100,000 males and 721 per 100,000 females. Among males, suicides and traffic accidents were the most common causes of death (the values of the SEYLLp were: 1098 years and 887 years per 100,000 people, respectively). Among females, the SEYLLp values were 183 years due to traffic accidents and 143 years due to suicides (per 100,000 people). Conclusions A decrease in the number of years of life lost due to external causes is much higher among females. The authors observe that a growing number of suicides contribute to an increase in the value of the SEYLLp index. This directly contributes to over-mortality of males due to external causes. The analysis of the years of life lost focuses on the social and economic aspects of premature mortality due to external causes. PMID:24810942

Internal radiation exposure of Ground Self-Defense Force members involved in the management of the Fukushima Nuclear Power Plant disaster.

PubMed

Naoi, Yutaka; Fujikawa, Akira; Kyoto, Yukishige; Kunishima, Naoaki; Ono, Masahiro; Watanabe, Yukie

2013-01-01

When the Great East Japan Earthquake occurred on March 11, 2011, the Ground Self-Defense Force (GSDF) was dispatched nationally to Northeast area in Japan. The highly trained GSDF members were simultaneously assigned to various missions for the Fukushima Nuclear Power Plants disaster. The missions of GSDF terminated on August 31, 2011. Special medical examinations were conducted for the members as they returned to each military unit. GSDF members who were assigned to the nuclear power plant were at risk of radiation exposure; therefore, pocket dosimeters were used to assess external radiation exposure. A few months after the mission was terminated, measurements of internal radiation exposure were performed. This is the first report of the internal exposure of GSDF members who worked in the restricted radiation contamination area. Here, we report the amounts of internal and external exposure of and the equipment used by the GSDF members.

Public member dose assessment of Bushehr Nuclear Power Plant under normal operation by modeling the fallout from stack using the HYSPLIT atmospheric dispersion model.

PubMed

Zali, A; Shamsaei Zafarghandi, M; Feghhi, S A; Taherian, A M

2017-05-01

In this work, public dose resulting from fission products released from Bushehr Nuclear Power Plant (BNPP) under normal operation is assessed. Due to the long range transport of radionuclides in this work (80 km) and considering terrain and meteorological data, HYbrid Single-Particle Lagrangian Integrated Trajectory (HYsplit) model, which uses three dimensional long-range numerical models, has been employed to calculate atmospheric dispersion. Annual effective dose calculation is carried out for inhalation, ingestion, and external exposure pathways in 16directions and within 80 km around the site for representative person. The results showed the maximum dose of inhalation and external exposure for adults is 3.8 × 10 -8 Sv/y in the SE direction and distance of 600 m from the BNPP site which is less than ICRP 103 recommended dose limit (1 mSv). Children and infants' doses are higher in comparison with adults, although they are less than 1 mSv. Ingestion dose percentage in the total dose is less than 0.1%. The results of this study underestimate the Final Safety Analysis Report ofBNPP-1 (FSAR)data. Copyright © 2017 Elsevier Ltd. All rights reserved.

THE HUMAN EXPOSURE DATABASE SYSTEM (HEDS)-PUTTING THE NHEXAS DATA ON-LINE

EPA Science Inventory

The EPA's National Exposure Research Laboratory (NERL) has developed an Internet accessible Human Exposure Database System (HEDS) to provide the results of NERL human exposure studies to both the EPA and the external scientific communities. The first data sets that will be ava...

Emotional Desensitization to Violence Contributes to Adolescents' Violent Behavior.

PubMed

Mrug, Sylvie; Madan, Anjana; Windle, Michael

2016-01-01

Many adolescents are exposed to violence in their schools, communities and homes. Exposure to violence at high levels or across multiple contexts has been linked with emotional desensitization, indicated by low levels of internalizing symptoms. However, the long-term consequences of such desensitization are unknown. This study examined emotional desensitization to violence, together with externalizing problems, as mediators of the relationship between exposure to violence in pre-adolescence and violent behavior in late adolescence. A community sample of youth (N = 704; 48% female; 76% African American, 22% Caucasian) reported on their exposure to violence in multiple settings at ages 11, 13 and 18. Internalizing and externalizing problems were assessed at ages 11 and 13; violent behavior was measured at age 18. Structural Equation Modeling showed that exposure to high levels of violence at age 11 was associated with lower levels of internalizing problems (quadratic effect) at age 13, as was exposure to violence across multiple contexts (linear effect). In turn, fewer internalizing problems and more externalizing problems at age 13 predicted more violent behavior at age 18. The results suggest that emotional desensitization to violence in early adolescence contributes to serious violence in late adolescence.

Emotional Desensitization to Violence Contributes to Adolescents’ Violent Behavior

PubMed Central

Mrug, Sylvie; Madan, Anjana; Windle, Michael

2015-01-01

Many adolescents are exposed to violence in their schools, communities and homes. Exposure to violence at high levels or across multiple contexts has been linked with emotional desensitization, indicated by low levels of internalizing symptoms. However, the long-term consequences of such desensitization are unknown. This study examined emotional desensitization to violence, together with externalizing problems, as mediators of the relationship between exposure to violence in pre-adolescence and violent behavior in late adolescence. A community sample of youth (N=704; 48% female; 76% African American, 22% Caucasian) reported on their exposure to violence in multiple settings at ages 11, 13 and 18. Internalizing and externalizing problems were assessed at ages 11 and 13; violent behavior was measured at age 18. Structural Equation Modeling showed that exposure to high levels of violence at age 11 was associated with lower levels of internalizing problems (quadratic effect) at age 13, as was exposure to violence across multiple contexts (linear effect). In turn, fewer internalizing problems and more externalizing problems at age 13 predicted more violent behavior at age 18. The results suggest that emotional desensitization to violence in early adolescence contributes to serious violence in late adolescence. PMID:25684447

Internalizing and Externalizing Subtypes in Female Sexual Assault Survivors: Implications for the Understanding of Complex PTSD

ERIC Educational Resources Information Center

Miller, Mark W.; Resick, Patricia A.

2007-01-01

This study replicated and extended findings of internalizing and externalizing subtypes of posttraumatic psychopathology (Miller, M. W., Greif, J. L., & Smith, A. A. (2003). Multidimensional Personality Questionnaire profiles of veterans with traumatic combat exposure: Internalizing and externalizing subtypes. "Psychological Assessment, 15",…

Non-invasive biomonitoring for PFRs and PBDEs: new insights in analysis of human hair externally exposed to selected flame retardants.

PubMed

Kucharska, Agnieszka; Covaci, Adrian; Vanermen, Guido; Voorspoels, Stefan

2015-02-01

In this study, we investigated the hypothesis whether externally adsorbed and internally deposited flame retardants (FRs) in hair could be distinguished. To this extent, hair samples collected from one volunteer were exposed under controlled conditions to phosphate FR (PFR) and polybrominated diphenyl ether (PBDE) standards to mimic external contamination. Afterwards, suitable washing procedures to selectively remove contaminants from the hair surface were investigated. The samples were measured by GC-(ECNI)-MS for PBDEs and LC-(ESI+)-MS/MS for PFRs. All investigated compounds were transferred onto the hair surface. One of the most important finding was that dust particles are not mandatory to transfer compounds on the hair surface and to be able to measure high levels of compounds in human hair. To assess different protocols to selectively remove external contamination, the exposed hair samples were washed in different media before analysis: water, methanol, hexane:dichloromethane (1:1, v/v), acetone and shampoo. Results indicated that there is no washing medium able to entirely and exclusively remove external contamination. Among investigated media, methanol removed a meaningful part of the external contamination (42-105%), but the removal efficiencies differed among compounds. We therefore concluded that hair should not be washed prior to analysis and in case of visible contamination (e.g. with cosmetic products), water would be the recommended agent. Organic solvents should not be used for the washing step. Although it is impossible to distinguish external from internal exposure, hair samples may be used as valuable biomarker of human exposure, providing a measure of integral exposure. To the best of our knowledge, this is the first study which has used externally exposed hair samples to PBDEs and PFRs. Copyright © 2014 Elsevier B.V. All rights reserved.

Prenatal exposure estimation of BPA and DEHP using integrated external and internal dosimetry: A case study.

PubMed

Martínez, M A; Rovira, J; Sharma, R Prasad; Nadal, M; Schuhmacher, M; Kumar, V

2017-10-01

Prenatal exposure to Endocrine disruptors (EDs), such as Bisphenol A (BPA) and di (2-ethylhexyl) phthalate (DEHP), has been associated with obesity and diabetes diseases in childhood, as well as reproductive, behavioral and neurodevelopment problems. The aim of this study was to estimate the prenatal exposure to BPA and DEHP through food consumption for pregnant women living in Tarragona County (Spain). Probabilistic calculations of prenatal exposure were estimated by integrated external and internal dosimetry modelling, physiologically based pharmacokinetic (PBPK) model, using a Monte-Carlo simulation. Physical characteristic data from the cohort, along with food intake information from the questionnaires (concentrations of BPA and DEHP in different food categories and the range of the different food ratios), were used to estimate the value of the total dietary intake for the Tarragona pregnancy cohort. The major contributors to the total dietary intake of BPA were canned fruits and vegetables, followed by canned meat and meat products. In turn, milk and dairy products, followed by ready to eat food (including canned dinners), were the most important contributors to the total dietary intake of DEHP. Despite the dietary variations among the participants, the intakes of both chemicals were considerably lower than their respective current tolerable daily intake (TDI) values established by the European Food Safety Authority (EFSA). Internal dosimetry estimates suggest that the plasma concentrations of free BPA and the most important DEHP metabolite, mono (2-ethylhexyl) phthalate (MEHP), in pregnant women were characterized by transient peaks (associated with meals) and short half-lives (< 2h). In contrast, fetal exposure was characterized by a low and sustained basal BPA and MEHP concentration due to a lack of metabolic activity in the fetus. Therefore, EDs may have a greater effect on developing organs in young children or in the unborn child. Copyright © 2017 Elsevier Inc. All rights reserved.

PREDICTING THE RISKS OF NEUROTOXIC VOLATILE ORGANIC COMPOUNDS BASED ON TARGET TISSUE DOSE.

EPA Science Inventory

Quantitative exposure-dose-response models relate the external exposure of a substance to the dose in the target tissue, and then relate the target tissue dose to production of adverse outcomes. We developed exposure-dose-response models to describe the affects of acute exposure...

Material degradation due to moisture and temperature. Part 1: mathematical model, analysis, and analytical solutions

NASA Astrophysics Data System (ADS)

Xu, C.; Mudunuru, M. K.; Nakshatrala, K. B.

2016-11-01

The mechanical response, serviceability, and load-bearing capacity of materials and structural components can be adversely affected due to external stimuli, which include exposure to a corrosive chemical species, high temperatures, temperature fluctuations (i.e., freezing-thawing), cyclic mechanical loading, just to name a few. It is, therefore, of paramount importance in several branches of engineering—ranging from aerospace engineering, civil engineering to biomedical engineering—to have a fundamental understanding of degradation of materials, as the materials in these applications are often subjected to adverse environments. As a result of recent advancements in material science, new materials such as fiber-reinforced polymers and multi-functional materials that exhibit high ductility have been developed and widely used, for example, as infrastructural materials or in medical devices (e.g., stents). The traditional small-strain approaches of modeling these materials will not be adequate. In this paper, we study degradation of materials due to an exposure to chemical species and temperature under large strain and large deformations. In the first part of our research work, we present a consistent mathematical model with firm thermodynamic underpinning. We then obtain semi-analytical solutions of several canonical problems to illustrate the nature of the quasi-static and unsteady behaviors of degrading hyperelastic solids.

Manganese Exposure from Drinking Water and Children’s Classroom Behavior in Bangladesh

PubMed Central

Khan, Khalid; Factor-Litvak, Pam; Wasserman, Gail A.; Liu, Xinhua; Ahmed, Ershad; Parvez, Faruque; Slavkovich, Vesna; Levy, Diane; Mey, Jacob; van Geen, Alexander

2011-01-01

Background: Evidence of neurological, cognitive, and neuropsychological effects of manganese (Mn) exposure from drinking water (WMn) in children has generated widespread public health concern. At elevated exposures, Mn has been associated with increased levels of externalizing behaviors, including irritability, aggression, and impulsivity. Little is known about potential effects at lower exposures, especially in children. Moreover, little is known regarding potential interactions between exposure to Mn and other metals, especially arsenic (As). Objectives: We conducted a cross-sectional study of 201 children to investigate associations of Mn and As in tube well water with classroom behavior among elementary school children, 8–11 years of age, in Araihazar, Bangladesh. Methods: Data on exposures and behavioral outcomes were collected from the participants at the baseline of an ongoing longitudinal study of child intelligence. Study children were rated by their school teachers on externalizing and internalizing items of classroom behavior using the standardized Child Behavior Checklist-Teacher’s Report Form (CBCL-TRF). Results: Log-transformed WMn was positively and significantly associated with TRF internalizing [estimated β = 0.82; 95% confidence interval (CI), 0.08–1.56; p = 0.03], TRF externalizing (estimated β = 2.59; 95% CI, 0.81–4.37; p =0.004), and TRF total scores (estimated β = 3.35; 95% CI, 0.86–5.83; p = 0.008) in models that adjusted for log-transformed water arsenic (WAs) and sociodemographic covariates. We also observed a positive monotonic dose–response relationship between WMn and TRF externalizing and TRF total scores among the participants of the study. We did not find any significant associations between WAs and various scales of TRF scores. Conclusion: These observations reinforce the growing concern regarding the neurotoxicologic effects of WMn in children. PMID:21493178

Assessing Occupational Exposure to Chemicals in an International Epidemiological Study of Brain Tumours

PubMed Central

van Tongeren, Martie

2013-01-01

The INTEROCC project is a multi-centre case–control study investigating the risk of developing brain cancer due to occupational chemical and electromagnetic field exposures. To estimate chemical exposures, the Finnish Job Exposure Matrix (FINJEM) was modified to improve its performance in the INTEROCC study and to address some of its limitations, resulting in the development of the INTEROCC JEM. An international team of occupational hygienists developed a crosswalk between the Finnish occupational codes used in FINJEM and the International Standard Classification of Occupations 1968 (ISCO68). For ISCO68 codes linked to multiple Finnish codes, weighted means of the exposure estimates were calculated. Similarly, multiple ISCO68 codes linked to a single Finnish code with evidence of heterogeneous exposure were refined. One of the key time periods in FINJEM (1960–1984) was split into two periods (1960–1974 and 1975–1984). Benzene exposure estimates in early periods were modified upwards. The internal consistency of hydrocarbon exposures and exposures to engine exhaust fumes was improved. Finally, exposure to polycyclic aromatic hydrocarbon and benzo(a)pyrene was modified to include the contribution from second-hand smoke. The crosswalk ensured that the FINJEM exposure estimates could be applied to the INTEROCC study subjects. The modifications generally resulted in an increased prevalence of exposure to chemical agents. This increased prevalence of exposure was not restricted to the lowest categories of cumulative exposure, but was seen across all levels for some agents. Although this work has produced a JEM with important improvements compared to FINJEM, further improvements are possible with the expansion of agents and additional external data. PMID:23467593

Relationship between LINE-1 methylation pattern and pesticide exposure in urban sprayers.

PubMed

Benitez-Trinidad, Alma Betsaida; Medina-Díaz, Irma Martha; Bernal-Hernández, Yael Yvette; Barrón-Vivanco, Briscia Socorro; González-Arias, Cyndia Azucena; Herrera-Moreno, José Francisco; Alvarado-Cruz, Isabel; Quintanilla-Vega, Betzabet; Rojas-García, Aurora Elizabeth

2018-03-01

Recently a relationship has been reported between pesticide exposure and changes in global DNA methylation patterns. Urban sprayers are a particularly vulnerable population because of the high risk of pesticide exposure that their work implies. Therefore, the aim of this study was to estimate the changes in the Long Interspersed Nucleotide Element (LINE-1) in urban sprayers and its relationship with pesticide exposure. The study population consisted of 190 individuals stratified into three study groups: no occupational pesticide exposure; moderate exposure, and high exposure. Pesticide exposure and other external factors such as diet, lifestyle, and others were evaluated through a validated questionnaire, and the butyrylcholinesterase enzyme activity was evaluated spectrophotometrically and used as exposure biomarker. DNA methylation was evaluated by pyrosequencing on bisulfite-treated DNA. The results showed a significant decrease of %5mC in both the moderate- and high-exposure groups with respect to the non-exposed group (p < 0.05). In addition, alcohol intake was associated with a higher percentage of LINE- 1 methylation. In conclusion, our results suggest that occupational pesticide exposure and external factors appears to modify the DNA methylation pattern measured through LINE-1. Copyright © 2018 Elsevier Ltd. All rights reserved.

Low Vagal Tone Magnifies the Association Between Psychosocial Stress Exposure and Internalizing Psychopathology in Adolescents

PubMed Central

McLaughlin, Katie A.; Rith-Najarian, Leslie; Dirks, Melanie A.; Sheridan, Margaret A.

2014-01-01

Vagal tone is a measure of cardiovascular function that facilitates adaptive responses to environmental challenge. Low vagal tone is associated with poor emotional and attentional regulation in children and has been conceptualized as a marker of sensitivity to stress. We investigated whether the associations of a wide range of psychosocial stressors with internalizing and externalizing psychopathology were magnified in adolescents with low vagal tone. Resting heart period data were collected from a diverse community sample of adolescents (ages 13–17; N =168). Adolescents completed measures assessing internalizing and externalizing psychopathology and exposure to stressors occurring in family, peer, and community contexts. Respiratory sinus arrhythmia (RSA) was calculated from the interbeat interval time series. We estimated interactions between RSA and stress exposure in predicting internalizing and externalizing symptoms and evaluated whether interactions differed by gender. Exposure to psychosocial stressors was associated strongly with psychopathology. RSA was unrelated to internalizing or externalizing problems. Significant interactions were observed between RSA and child abuse, community violence, peer victimization, and traumatic events in predicting internalizing but not externalizing symptoms. Stressors were positively associated with internalizing symptoms in adolescents with low RSA but not in those with high RSA. Similar patterns were observed for anxiety and depression. These interactions were more consistently observed for male than female individuals. Low vagal tone is associated with internalizing psychopathology in adolescents exposed to high levels of stressors. Measurement of vagal tone in clinical settings might provide useful information about sensitivity to stress in child and adolescent clients. PMID:24156380

Children Affected by War and Armed Conflict: Parental Protective Factors and Resistance to Mental Health Symptoms

PubMed Central

Slone, Michelle; Shoshani, Anat

2017-01-01

This study examined the role of parenting styles and parental warmth in moderating relations between exposure to political life events and mental health symptoms among 277 Israeli adolescents aged 12–14 and their parents, who had been exposed to protracted periods of war, missile bombardments, and terrorism. Adolescents completed the Political Life Events (PLE) scale, Brief Symptom Inventory and questionnaires regarding parenting style and parental warmth. The primary caregiver completed the Child Behavior Checklist for assessment of the child’s internalizing and externalizing symptoms. Results confirmed that severity of PLE exposure was positively correlated with psychological distress and with internalizing and externalizing symptoms. Maternal authoritativeness and warmth functioned as protective factors and had moderating effects on the relation between PLE exposure and mental health symptoms. In contrast, maternal authoritarianism exacerbated the relation between PLE exposure and children’s externalizing symptoms. Fathers’ parenting style and warmth had no significant relationship with children’s mental health outcomes. These findings have important clinical and practical implications for parental guidance and support during periods of war and armed conflict. PMID:28878705

Children Affected by War and Armed Conflict: Parental Protective Factors and Resistance to Mental Health Symptoms.

PubMed

Slone, Michelle; Shoshani, Anat

2017-01-01

This study examined the role of parenting styles and parental warmth in moderating relations between exposure to political life events and mental health symptoms among 277 Israeli adolescents aged 12-14 and their parents, who had been exposed to protracted periods of war, missile bombardments, and terrorism. Adolescents completed the Political Life Events (PLE) scale, Brief Symptom Inventory and questionnaires regarding parenting style and parental warmth. The primary caregiver completed the Child Behavior Checklist for assessment of the child's internalizing and externalizing symptoms. Results confirmed that severity of PLE exposure was positively correlated with psychological distress and with internalizing and externalizing symptoms. Maternal authoritativeness and warmth functioned as protective factors and had moderating effects on the relation between PLE exposure and mental health symptoms. In contrast, maternal authoritarianism exacerbated the relation between PLE exposure and children's externalizing symptoms. Fathers' parenting style and warmth had no significant relationship with children's mental health outcomes. These findings have important clinical and practical implications for parental guidance and support during periods of war and armed conflict.

Health-related external cost assessment in Europe: methodological developments from ExternE to the 2013 Clean Air Policy Package.

PubMed

van der Kamp, Jonathan; Bachmann, Till M

2015-03-03

"Getting the prices right" through internalizing external costs is a guiding principle of environmental policy making, one recent example being the EU Clean Air Policy Package released at the end of 2013. It is supported by impact assessments, including monetary valuation of environmental and health damages. For over 20 years, related methodologies have been developed in Europe in the Externalities of Energy (ExternE) project series and follow-up activities. In this study, we aim at analyzing the main methodological developments over time from the 1990s until today with a focus on classical air pollution-induced human health damage costs. An up-to-date assessment including the latest European recommendations is also applied. Using a case from the energy sector, we identify major influencing parameters: differences in exposure modeling and related data lead to variations in damage costs of up to 21%; concerning risk assessment and monetary valuation, differences in assessing long-term exposure mortality risks together with assumptions on particle toxicity explain most of the observed changes in damage costs. These still debated influencing parameters deserve particular attention when damage costs are used to support environmental policy making.

Urinary excretion of heptanones, heptanoles and 2,5-heptanedione after controlled acute exposure of volunteers to n-heptane.

PubMed

Rossbach, Bernd; Kegel, Peter; Letzel, Stephan

2018-03-27

A lack of well-established parameters and assessment values currently impairs biomonitoring of n-heptane exposure. Using controlled inhalation experiments, we collected information on urinary n-heptane metabolite concentrations and the time course of metabolite excretion. Relationships between external and internal exposure were analysed to investigate the suitability of selected metabolites to reflect n-heptane uptake. Twenty healthy, non-smoking males (aged 19-38 years, median 25.5) were exposed for 3 h to 167, 333 and 500 ppm n-heptane, each. Spot urine samples of the volunteers, collected before exposure and during the following 24 h, were analysed for heptane-2-one, 3-one, 4-one, 2,5-dione, 1-ol, 2-ol, 3-ol, and 4-ol using headspace solid phase dynamic extraction gas chromatography/mass spectrometry (HS-SPDE-GC/MS). Starting from median pre-exposure concentrations between <0.5 (3-one) and 82.9 μg/L (4-one), exposure increased the concentrations for all parameters except for 4-one. Median post-exposure concentrations ranged up to 840.4 μg/L (2-ol) and decreased with half-lifes <3 h after exposure. Non-parametric correlation analyses (n = 47, p < 0.05) revealed weak to moderate associations of volume related metabolite excretion with external exposure for 2-one, 3-one and 2,5-dione (R = 0.332-0.753). Heptanol excretion was moderately associated with exposure (R ≥ 0.509) only after creatinine adjustment. Lacking association with external exposure impedes the use of 4-one as heptane biomarker, whereas 2-ol and 3-ol turned out to be sensitive indicators of exposure if creatinine correction is applied. By providing fundamental data on a panel of eight potential heptane metabolites, our study can help to promote biological monitoring of n-heptane exposure. Copyright © 2018 Elsevier B.V. All rights reserved.

Mitochondrial toxicity in human pregnancy: an update on clinical and experimental approaches in the last 10 years.

PubMed

Morén, Constanza; Hernández, Sandra; Guitart-Mampel, Mariona; Garrabou, Glòria

2014-09-22

Mitochondrial toxicity can be one of the most dreadful consequences of exposure to a wide range of external agents including pathogens, therapeutic agents, abuse drugs, toxic gases and other harmful chemical substances. However, little is known about the effects of mitochondrial toxicity on pregnant women exposed to these agents that may exert transplacental activity and condition fetal remodeling. It has been hypothesized that mitochondrial toxicity may be involved in some adverse obstetric outcomes. In the present study, we investigated the association between exposure to mitochondrial toxic agents and pathologic conditions ranging from fertility defects, detrimental fetal development and impaired newborn health due to intra-uterine exposure. We have reviewed data from studies in human subjects to propose mechanisms of mitochondrial toxicity that could be associated with the symptoms present in both exposed pregnant and fetal patients. Since some therapeutic interventions or accidental exposure cannot be avoided, further research is needed to gain insight into the molecular pathways leading to mitochondrial toxicity during pregnancy. The ultimate objective of these studies should be to reduce the mitochondrial toxicity of these agents and establish biomarkers for gestational monitoring of harmful effects.

A 3 year update on the influence of noise on performance and behavior.

PubMed

Clark, Charlotte; Sörqvist, Patrik

2012-01-01

The effect of noise exposure on human performance and behavior continues to be a focus for research activities. This paper reviews developments in the field over the past 3 years, highlighting current areas of research, recent findings, and ongoing research in two main research areas: Field studies of noise effects on children's cognition and experimental studies of auditory distraction. Overall, the evidence for the effects of external environmental noise on children's cognition has strengthened in recent years, with the use of larger community samples and better noise characterization. Studies have begun to establish exposure-effect thresholds for noise effects on cognition. However, the evidence remains predominantly cross-sectional and future research needs to examine whether sound insulation might lessen the effects of external noise on children's learning. Research has also begun to explore the link between internal classroom acoustics and children's learning, aiming to further inform the design of the internal acoustic environment. Experimental studies of the effects of noise on cognitive performance are also reviewed, including functional differences in varieties of auditory distraction, semantic auditory distraction, individual differences in susceptibility to auditory distraction, and the role of cognitive control on the effects of noise on understanding and memory of target speech materials. In general, the results indicate that there are at least two functionally different types of auditory distraction: One due to the interruption of processes (as a result of attention being captured by the sound), another due to interference between processes. The magnitude of the former type is related to individual differences in cognitive control capacities (e.g., working memory capacity); the magnitude of the latter is not. Few studies address noise effects on behavioral outcomes, emphasizing the need for researchers to explore noise effects on behavior in more detail.

[Mathematic concept model of accumulation of functional disorders associated with environmental factors].

PubMed

Zaĭtseva, N V; Trusov, P V; Kir'ianov, D A

2012-01-01

The mathematic concept model presented describes accumulation of functional disorders associated with environmental factors, plays predictive role and is designed for assessments of possible effects caused by heterogenous factors with variable exposures. Considering exposure changes with self-restoration process opens prospects of using the model to evaluate, analyse and manage occupational risks. To develop current theoretic approaches, the authors suggested a model considering age-related body peculiarities, systemic interactions of organs, including neuro-humoral regulation, accumulation of functional disorders due to external factors, rehabilitation of functions during treatment. General objective setting covers defining over a hundred unknow coefficients that characterize speed of various processes within the body. To solve this problem, the authors used iteration approach, successive identification, that starts from the certain primary approximation of the model parameters and processes subsequent updating on the basis of new theoretic and empirical knowledge.

Interactive effects of early and recent exposure to stressful contexts on cortisol reactivity in middle childhood.

PubMed

Jaffee, Sara R; McFarquhar, Tara; Stevens, Suzanne; Ouellet-Morin, Isabelle; Melhuish, Edward; Belsky, Jay

2015-02-01

Given mixed findings as to whether stressful experiences and relationships are associated with increases or decreases in children's cortisol reactivity, we tested whether a child's developmental history of risk exposure explained variation in cortisol reactivity to an experimentally induced task. We also tested whether the relationship between cortisol reactivity and children's internalizing and externalizing problems varied as a function of their developmental history of stressful experiences and relationships. Participants included 400 children (M = 9.99 years, SD = 0.74 years) from the Children's Experiences and Development Study. Early risk exposure was measured by children's experiences of harsh, nonresponsive parenting at 3 years. Recent risk exposure was measured by children's exposure to traumatic events in the past year. Children's cortisol reactivity was measured in response to a social provocation task and parents and teachers described children's internalizing and externalizing problems. The effect of recent exposure to traumatic events was partially dependent upon a child's early experiences of harsh, nonresponsive parenting: the more traumatic events children had recently experienced, the greater their cortisol reactivity if they had experienced lower (but not higher) levels of harsh, nonresponsive parenting at age 3. The lowest levels of cortisol reactivity were observed among children who had experienced the most traumatic events in the past year and higher (vs. lower) levels of harsh, nonresponsive parenting in early childhood. Among youth who experienced harsh, nonresponsive parent-child relationships in early childhood and later traumatic events, lower levels of cortisol reactivity were associated with higher levels of internalizing and externalizing problems. Hypothalamic-pituitary-adrenal (HPA) axis reactivity to psychological stressors and the relationship between HPA axis reactivity and children's internalizing and externalizing problems vary as a function of a child's developmental history of exposure to stressful relationships and experiences. © 2014 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.

INTRACELLULAR ION CONCENTRATIONS IN BRANCHIAL EPITHELIAL CELLS OF BROWN TROUT (SALMO TRUTTA L.) DETERMINED BY X-RAY MICROANALYSIS

PubMed

Morgan; Potts; Oates

1994-09-01

The intracellular concentrations of sodium, chloride, phosphorus and potassium under normal conditions in pavement epithelial (PE) cells of brown trout (Salmo trutta) gill were 66, 51, 87 and 88 mmol l-1 respectively. The concentrations of these elements under identical conditions in mitochondria-rich (MR) cells were not significantly different, except for that of chlorine, which was lower in MR cells (40 mmol l-1). The concentration of sodium in the PE cells decreased slightly after exposure of the fish to low external [Na+] (25 µmol l-1) for 7 days but increased greatly within 5 min of subsequent exposure to 1 mmol l-1 external Na+. These changes in external [Na+] had no significant effect on MR cells. Exposure of fish to low [Cl-] (25 µmol l-1) had no effect on PE or MR cells, but on exposure to 1 mmol l-1 Cl- the concentrations of chlorine, phosphorus and potassium in both types of cells increased, whilst the intracellular sodium concentration decreased only in MR cells. The PE cells were little affected by exposure of the fish to the carbonic anhydrase inhibitor acetazolamide. In contrast, 0.5 mmol l-1 external acetazolamide caused a significant decrease in intracellular phosphorus, chlorine and potassium concentrations in MR cells. This suggests that the PE cells are the sites of sodium uptake in the gills of the brown trout and that chloride uptake occurs via the MR cells. These results are discussed with respect to the sites and possible mechanisms of ionic exchange in freshwater vertebrates.

Response of Cultured Neuronal Network Activity After High-Intensity Power Frequency Magnetic Field Exposure

PubMed Central

Saito, Atsushi; Takahashi, Masayuki; Makino, Kei; Suzuki, Yukihisa; Jimbo, Yasuhiko; Nakasono, Satoshi

2018-01-01

High-intensity and low frequency (1–100 kHz) time-varying electromagnetic fields stimulate the human body through excitation of the nervous system. In power frequency range (50/60 Hz), a frequency-dependent threshold of the external electric field-induced neuronal modulation in cultured neuronal networks was used as one of the biological indicator in international guidelines; however, the threshold of the magnetic field-induced neuronal modulation has not been elucidated. In this study, we exposed rat brain-derived neuronal networks to a high-intensity power frequency magnetic field (hPF-MF), and evaluated the modulation of synchronized bursting activity using a multi-electrode array (MEA)-based extracellular recording technique. As a result of short-term hPF-MF exposure (50–400 mT root-mean-square (rms), 50 Hz, sinusoidal wave, 6 s), the synchronized bursting activity was increased in the 400 mT-exposed group. On the other hand, no change was observed in the 50–200 mT-exposed groups. In order to clarify the mechanisms of the 400 mT hPF-MF exposure-induced neuronal response, we evaluated it after blocking inhibitory synapses using bicuculline methiodide (BMI); subsequently, increase in bursting activity was observed with BMI application, and the response of 400 mT hPF-MF exposure disappeared. Therefore, it was suggested that the response of hPF-MF exposure was involved in the inhibitory input. Next, we screened the inhibitory pacemaker-like neuronal activity which showed autonomous 4–10 Hz firing with CNQX and D-AP5 application, and it was confirmed that the activity was reduced after 400 mT hPF-MF exposure. Comparison of these experimental results with estimated values of the induced electric field (E-field) in the culture medium revealed that the change in synchronized bursting activity occurred over 0.3 V/m, which was equivalent to the findings of a previous study that used the external electric fields. In addition, the results suggested that the potentiation of neuronal activity after 400 mT hPF-MF exposure was related to the depression of autonomous activity of pacemaker-like neurons. Our results indicated that the synchronized bursting activity was increased by hPF-MF exposure (E-field: >0.3 V/m), and the response was due to reduced inhibitory pacemaker-like neuronal activity. PMID:29662453

Association of prenatal exposure to benzodiazepines and child internalizing problems: A sibling-controlled cohort study.

PubMed

Brandlistuen, Ragnhild E; Ystrom, Eivind; Hernandez-Diaz, Sonia; Skurtveit, Svetlana; Selmer, Randi; Handal, Marte; Nordeng, Hedvig

2017-01-01

During pregnancy, many women experience sleep problems and anxiety that require treatment. The long-term safety for the child of maternal benzodiazepine (BZD) and z-hypnotic use during pregnancy remains controversial. We conducted a cohort and a sibling control study using data from the Norwegian Mother and Child Cohort Study. Data on use of BZD and z-hypnotics, internalizing and externalizing outcomes, and covariates were collected from mothers at gestational weeks 17 and 30 and when children were 0.5, 1.5, and 3 years of age. The total sample consisted of 71,996 children (19,297 siblings) at 1.5 years and 55,081 children (13,779 siblings) at 3 years. Short-term use was defined as use in one pregnancy period only. Long-term use was defined as use in two or more pregnancy periods. Linear full cohort random-effect and sibling-matched fixed-effect regression models were used to compare internalizing and externalizing behavior in children prenatally exposed compared to those unexposed in the full cohort of pregnancies accounting for family clusters, as well as within sibling clusters comparing pregnancies with discordant exposures. Propensity score (PS) adjustment included variables on indication for use (sleep problems, symptoms of anxiety and depression) and other potential confounding factors. Long-term prenatal exposure to BZD or z-hypnotics was associated with increased internalizing behavior in crude cohort analyses and at age 1.5 years after PS adjustment in sibling-matched fixed-effect models [β 0.60, 95% confidence interval 0.17-0.95]. Analyses on specific drug groups showed that prenatal exposure to BZD-anxiolytics was associated with increased internalizing problems at both 1.5 years [β 0.25, 0.01-0.49] and 3 years [β 0.26, 0.002-0.52] while exposure to z-hypnotics was not associated with any adverse outcomes after adjustment. The findings suggest a moderate association between BZD-anxiolytic exposure and child internalizing problems that is not likely due to stable familial confounding factors.

The importance of inclusion of kinetic information in the extrapolation of high-to-low concentrations for human limit setting.

PubMed

Geraets, Liesbeth; Zeilmaker, Marco J; Bos, Peter M J

2018-01-05

Human health risk assessment of inhalation exposures generally includes a high-to-low concentration extrapolation. Although this is a common step in human risk assessment, it introduces various uncertainties. One of these uncertainties is related to the toxicokinetics. Many kinetic processes such as absorption, metabolism or excretion can be subject to saturation at high concentration levels. In the presence of saturable kinetic processes of the parent compound or metabolites, disproportionate increases in internal blood or tissue concentration relative to the external concentration administered may occur resulting in nonlinear kinetics. The present paper critically reviews human health risk assessment of inhalation exposure. More specific, it emphasizes the importance of kinetic information for the determination of a safe exposure in human risk assessment of inhalation exposures assessed by conversion from a high animal exposure to a low exposure in humans. For two selected chemicals, i.e. methyl tert-butyl ether and 1,2-dichloroethane, PBTK-modelling was used, for illustrative purposes, to follow the extrapolation and conversion steps as performed in existing risk assessments for these chemicals. Human health-based limit values based on an external dose metric without sufficient knowledge on kinetics might be too high to be sufficiently protective. Insight in the actual internal exposure, the toxic agent, the appropriate dose metric, and whether an effect is related to internal concentration or dose is important. Without this, application of assessment factors on an external dose metric and the conversion to continuous exposure results in an uncertain human health risk assessment of inhalation exposures. Copyright © 2017 Elsevier B.V. All rights reserved.

Examining the Effects of External or Internal Radiation Exposure of Juvenile Mice on Late Morbidity after Infection with Influenza A.

PubMed

Misra, Ravi S; Johnston, Carl J; Groves, Angela M; DeDiego, Marta L; St Martin, Joe; Reed, Christina; Hernady, Eric; Miller, Jen-Nie; Love, Tanzy; Finkelstein, Jacob N; Williams, Jacqueline P

2015-07-01

A number of investigators have suggested that exposure to low-dose radiation may pose a potentially serious health risk. However, the majority of these studies have focused on the short-term rather than long-term effects of exposure to fixed source radiation, and few have examined the effects of internal contamination. Additionally, very few studies have focused on exposure in juveniles, when organs are still developing and could be more sensitive to the toxic effects of radiation. To specifically address whether early-life radiation injury may affect long-term immune competence, we studied 14-day-old juvenile pups that were either 5 Gy total-body irradiated or injected internally with 50 μCi soluble (137)Cs, then infected with influenza A virus at 26 weeks after exposure. After influenza infection, all groups demonstrated immediate weight loss. We found that externally irradiated, infected animals failed to recover weight relative to age-matched infected controls, but internally (137)Cs contaminated and infected animals had a weight recovery with a similar rate and degree as controls. Externally and internally irradiated mice demonstrated reduced levels of club cell secretory protein (CCSP) message in their lungs after influenza infection. The externally irradiated group did not recover CCSP expression even at the two-week time point after infection. Although the antibody response and viral titers did not appear to be affected by either radiation modality, there was a slight increase in monocyte chemoattractant protein (MCP)-1 expression in the lungs of externally irradiated animals 14 days after influenza infection, with increased cellular infiltration present. Notably, an increase in the number of regulatory T cells was seen in the mediastinal lymph nodes of irradiated mice relative to uninfected mice. These data confirm the hypothesis that early-life irradiation may have long-term consequences on the immune system, leading to an altered antiviral response.

HOx radical chemistry in oxidation flow reactors with low-pressure mercury lamps systematically examined by modeling

NASA Astrophysics Data System (ADS)

Peng, Z.; Day, D. A.; Stark, H.; Li, R.; Lee-Taylor, J.; Palm, B. B.; Brune, W. H.; Jimenez, J. L.

2015-11-01

Oxidation flow reactors (OFRs) using OH produced from low-pressure Hg lamps at 254 nm (OFR254) or both 185 and 254 nm (OFR185) are commonly used in atmospheric chemistry and other fields. OFR254 requires the addition of externally formed O3 since OH is formed from O3 photolysis, while OFR185 does not since O2 can be photolyzed to produce O3, and OH can also be formed from H2O photolysis. In this study, we use a plug-flow kinetic model to investigate OFR properties under a very wide range of conditions applicable to both field and laboratory studies. We show that the radical chemistry in OFRs can be characterized as a function of UV light intensity, H2O concentration, and total external OH reactivity (OHRext, e.g., from volatile organic compounds (VOCs), NOx, and SO2). OH exposure is decreased by added external OH reactivity. OFR185 is especially sensitive to this effect at low UV intensity due to low primary OH production. OFR254 can be more resilient against OH suppression at high injected O3 (e.g., 70 ppm), as a larger primary OH source from O3, as well as enhanced recycling of HO2 to OH, make external perturbations to the radical chemistry less significant. However if the external OH reactivity in OFR254 is much larger than OH reactivity from injected O3, OH suppression can reach 2 orders of magnitude. For a typical input of 7 ppm O3 (OHRO3 = 10 s-1), 10-fold OH suppression is observed at OHRext ~ 100 s-1, which is similar or lower than used in many laboratory studies. The range of modeled OH suppression for literature experiments is consistent with the measured values except for those with isoprene. The finding on OH suppression may have important implications for the interpretation of past laboratory studies, as applying OHexp measurements acquired under different conditions could lead to over a 1-order-of-magnitude error in the estimated OHexp. The uncertainties of key model outputs due to uncertainty in all rate constants and absorption cross-sections in the model are within ±25 % for OH exposure and within ±60 % for other parameters. These uncertainties are small relative to the dynamic range of outputs. Uncertainty analysis shows that most of the uncertainty is contributed by photolysis rates of O3, O2, and H2O and reactions of OH and HO2 with themselves or with some abundant species, i.e., O3 and H2O2. OHexp calculated from direct integration and estimated from SO2 decay in the model with laminar and measured residence time distributions (RTDs) are generally within a factor of 2 from the plug-flow OHexp. However, in the models with RTDs, OHexp estimated from SO2 is systematically lower than directly integrated OHexp in the case of significant SO2 consumption. We thus recommended using OHexp estimated from the decay of the species under study when possible, to obtain the most appropriate information on photochemical aging in the OFR. Using HOx-recycling vs. destructive external OH reactivity only leads to small changes in OHexp under most conditions. Changing the identity (rate constant) of external OH reactants can result in substantial changes in OHexp due to different reductions in OH suppression as the reactant is consumed. We also report two equations for estimating OH exposure in OFR254. We find that the equation estimating OHexp from measured O3 consumption performs better than an alternative equation that does not use it, and thus recommend measuring both input and output O3 concentrations in OFR254 experiments. This study contributes to establishing a firm and systematic understanding of the gas-phase HOx and Ox chemistry in these reactors, and enables better experiment planning and interpretation as well as improved design of future reactors.

HO x radical chemistry in oxidation flow reactors with low-pressure mercury lamps systematically examined by modeling

DOE PAGES

Peng, Z.; Day, D. A.; Stark, H.; ...

2015-11-20

Oxidation flow reactors (OFRs) using OH produced from low-pressure Hg lamps at 254 nm (OFR254) or both 185 and 254 nm (OFR185) are commonly used in atmospheric chemistry and other fields. OFR254 requires the addition of externally formed O 3 since OH is formed from O 3 photolysis, while OFR185 does not since O 2 can be photolyzed to produce O 3, and OH can also be formed from H 2O photolysis. In this study, we use a plug-flow kinetic model to investigate OFR properties under a very wide range of conditions applicable to both field and laboratory studies. Wemore » show that the radical chemistry in OFRs can be characterized as a function of UV light intensity, H 2O concentration, and total external OH reactivity (OHR ext, e.g., from volatile organic compounds (VOCs), NO x, and SO 2). OH exposure is decreased by added external OH reactivity. OFR185 is especially sensitive to this effect at low UV intensity due to low primary OH production. OFR254 can be more resilient against OH suppression at high injected O 3 (e.g., 70 ppm), as a larger primary OH source from O 3, as well as enhanced recycling of HO 2 to OH, make external perturbations to the radical chemistry less significant. However if the external OH reactivity in OFR254 is much larger than OH reactivity from injected O 3, OH suppression can reach 2 orders of magnitude. For a typical input of 7 ppm O 3 (OHR O3 = 10 s –1), 10-fold OH suppression is observed at OHR ext ~ 100 s –1, which is similar or lower than used in many laboratory studies. The range of modeled OH suppression for literature experiments is consistent with the measured values except for those with isoprene. The finding on OH suppression may have important implications for the interpretation of past laboratory studies, as applying OH exp measurements acquired under different conditions could lead to over a 1-order-of-magnitude error in the estimated OH exp. The uncertainties of key model outputs due to uncertainty in all rate constants and absorption cross-sections in the model are within ±25 % for OH exposure and within ±60 % for other parameters. These uncertainties are small relative to the dynamic range of outputs. Uncertainty analysis shows that most of the uncertainty is contributed by photolysis rates of O 3, O 2, and H 2O and reactions of OH and HO 2 with themselves or with some abundant species, i.e., O 3 and H 2O 2. OH exp calculated from direct integration and estimated from SO 2 decay in the model with laminar and measured residence time distributions (RTDs) are generally within a factor of 2 from the plug-flow OH exp. However, in the models with RTDs, OH exp estimated from SO 2 is systematically lower than directly integrated OH exp in the case of significant SO 2 consumption. We thus recommended using OH exp estimated from the decay of the species under study when possible, to obtain the most appropriate information on photochemical aging in the OFR. Using HO x-recycling vs. destructive external OH reactivity only leads to small changes in OH exp under most conditions. Changing the identity (rate constant) of external OH reactants can result in substantial changes in OH exp due to different reductions in OH suppression as the reactant is consumed. We also report two equations for estimating OH exposure in OFR254. We find that the equation estimating OH exp from measured O 3 consumption performs better than an alternative equation that does not use it, and thus recommend measuring both input and output O 3 concentrations in OFR254 experiments. As a result, this study contributes to establishing a firm and systematic understanding of the gas-phase HO x and O x chemistry in these reactors, and enables better experiment planning and interpretation as well as improved design of future reactors.« less

HO x radical chemistry in oxidation flow reactors with low-pressure mercury lamps systematically examined by modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Z.; Day, D. A.; Stark, H.

Oxidation flow reactors (OFRs) using OH produced from low-pressure Hg lamps at 254 nm (OFR254) or both 185 and 254 nm (OFR185) are commonly used in atmospheric chemistry and other fields. OFR254 requires the addition of externally formed O 3 since OH is formed from O 3 photolysis, while OFR185 does not since O 2 can be photolyzed to produce O 3, and OH can also be formed from H 2O photolysis. In this study, we use a plug-flow kinetic model to investigate OFR properties under a very wide range of conditions applicable to both field and laboratory studies. Wemore » show that the radical chemistry in OFRs can be characterized as a function of UV light intensity, H 2O concentration, and total external OH reactivity (OHR ext, e.g., from volatile organic compounds (VOCs), NO x, and SO 2). OH exposure is decreased by added external OH reactivity. OFR185 is especially sensitive to this effect at low UV intensity due to low primary OH production. OFR254 can be more resilient against OH suppression at high injected O 3 (e.g., 70 ppm), as a larger primary OH source from O 3, as well as enhanced recycling of HO 2 to OH, make external perturbations to the radical chemistry less significant. However if the external OH reactivity in OFR254 is much larger than OH reactivity from injected O 3, OH suppression can reach 2 orders of magnitude. For a typical input of 7 ppm O 3 (OHR O3 = 10 s –1), 10-fold OH suppression is observed at OHR ext ~ 100 s –1, which is similar or lower than used in many laboratory studies. The range of modeled OH suppression for literature experiments is consistent with the measured values except for those with isoprene. The finding on OH suppression may have important implications for the interpretation of past laboratory studies, as applying OH exp measurements acquired under different conditions could lead to over a 1-order-of-magnitude error in the estimated OH exp. The uncertainties of key model outputs due to uncertainty in all rate constants and absorption cross-sections in the model are within ±25 % for OH exposure and within ±60 % for other parameters. These uncertainties are small relative to the dynamic range of outputs. Uncertainty analysis shows that most of the uncertainty is contributed by photolysis rates of O 3, O 2, and H 2O and reactions of OH and HO 2 with themselves or with some abundant species, i.e., O 3 and H 2O 2. OH exp calculated from direct integration and estimated from SO 2 decay in the model with laminar and measured residence time distributions (RTDs) are generally within a factor of 2 from the plug-flow OH exp. However, in the models with RTDs, OH exp estimated from SO 2 is systematically lower than directly integrated OH exp in the case of significant SO 2 consumption. We thus recommended using OH exp estimated from the decay of the species under study when possible, to obtain the most appropriate information on photochemical aging in the OFR. Using HO x-recycling vs. destructive external OH reactivity only leads to small changes in OH exp under most conditions. Changing the identity (rate constant) of external OH reactants can result in substantial changes in OH exp due to different reductions in OH suppression as the reactant is consumed. We also report two equations for estimating OH exposure in OFR254. We find that the equation estimating OH exp from measured O 3 consumption performs better than an alternative equation that does not use it, and thus recommend measuring both input and output O 3 concentrations in OFR254 experiments. As a result, this study contributes to establishing a firm and systematic understanding of the gas-phase HO x and O x chemistry in these reactors, and enables better experiment planning and interpretation as well as improved design of future reactors.« less

The contribution of different forms of violence exposure to internalizing and externalizing symptoms among young South African adolescents.

PubMed

du Plessis, Bernice; Kaminer, Debra; Hardy, Anneli; Benjamin, Arlene

2015-07-01

While many youth are exposed to multiple forms of co-occurring violence, the comparative impact of different forms of violence on the mental health of children and adolescents has not been clearly established. Studies from low and middle income countries in particular are lacking. The present study examined the contribution of different forms of violence to internalizing and externalizing symptoms among young adolescents in South Africa. A community-based sample of 616 high school learners completed self-report scales assessing exposure to six different forms of violence and the severity of depression, aggression and conduct disorder symptoms. In bivariate analyses, all six forms of violence were significantly associated with internalizing and externalizing difficulties. When the contribution of all forms of violence to mental health outcomes was examined simultaneously, domestic victimization emerged as the strongest predictor of both internalizing and externalizing difficulties. Cumulative exposure to other forms of violence contributed further to the prediction of aggression and conduct disorder, but not depression. Recommendations for future research, and the implications of the findings for prioritizing the development of violence prevention and intervention initiatives in the South African context, are considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

Role of Parent and Peer Relationships and Individual Characteristics in Middle School Children's Behavioral Outcomes in the Face of Community Violence

PubMed Central

Salzinger, Suzanne; Rosario, Margaret; Feldman, Richard S.; Ng-Mak, Daisy S.

2010-01-01

This study examines processes linking inner-city community violence exposure to subsequent internalizing and externalizing problems. Hypothesized risk and protective factors from three ecological domains -- children's parent and peer relationships and individual characteristics -- were examined for mediating, moderating or independent roles in predicting problem behavior among 667 children over three years of middle school. Mediation was not found. However, parent and peer variables moderated the association between exposure and internalizing problems. Under high exposure, normally protective factors (e.g., attachment to parents) were less effective in mitigating exposure's effects than under low exposure; attachment to friends was more effective. Individual competence was independently associated with decreased internalizing problems. Variables from all domains, and exposure, were independently associated with externalizing problems. Protective factors (e.g., parent attachment) predicted decreased problems; risk factors (e.g., friends' delinquency) predicted increased problems. Results indicate community violence reduction as essential in averting inner-city adolescents' poor behavioral outcomes. PMID:21643493

Development of methods for avian oil toxicity studies using the double crested cormorant (Phalacrocorax auritus).

PubMed

Cunningham, Fred; Dean, Karen; Hanson-Dorr, Katie; Harr, Kendal; Healy, Kate; Horak, Katherine; Link, Jane; Shriner, Susan; Bursian, Steven; Dorr, Brian

2017-07-01

Oral and external dosing methods replicating field exposure were developed using the double crested cormorant (DCCO) to test the toxicity of artificially weathered Deepwater Horizon Mississippi Canyon 252 oil. The majority of previous oil dosing studies conducted on wild-caught birds used gavage methods to dose birds with oil and determine toxicity. However, rapid gut transit time of gavaged oil likely reduces oil absorption. In the present studies, dosing relied on injection of oil into live feeder fish for oral dosing of these piscivorous birds, or applying oil to body contour feathers resulting in transdermal oil exposure and oral exposure through preening. Both oral and external oil dosing studies identified oil-related toxicity endpoints associated with oxidative stress such as hemolytic anemia, liver and kidney damage, and immuno-modulation or compromise. External oil application allowed for controlled study of thermoregulatory stress as well. Infrared thermal images indicated significantly greater surface temperatures and heat loss in treated birds following external oil applications; however, measurements collected by coelomically implanted temperature transmitters showed that internal body temperatures were stable over the course of the study period. Birds exposed to oil externally consumed more fish than control birds, indicating metabolic compensation for thermal stress. Conversely, birds orally dosed with oil experienced hypothermia and consumed less fish compared to control birds. Published by Elsevier Inc.

An Exploratory Study: Assessment of Modeled Dioxin ...

EPA Pesticide Factsheets

EPA has released an external review draft entitled, An Exploratory Study: Assessment of Modeled Dioxin Exposure in Ceramic Art Studios(External Review Draft). The public comment period and the external peer-review workshop are separate processes that provide opportunities for all interested parties to comment on the document. In addition to consideration by EPA, all public comments submitted in accordance with this notice will also be forwarded to EPA’s contractor for the external peer-review panel prior to the workshop. EPA has realeased this draft document solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. This document has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency policy or determination. The purpose of this report is to describe an exploratory investigation of potential dioxin exposures to artists/hobbyists who use ball clay to make pottery and related products.

Systemic exposure to PAHs and benzene in firefighters suppressing controlled structure fires.

PubMed

Fent, Kenneth W; Eisenberg, Judith; Snawder, John; Sammons, Deborah; Pleil, Joachim D; Stiegel, Matthew A; Mueller, Charles; Horn, Gavin P; Dalton, James

2014-08-01

Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre-exposure levels for round 1. We found statistically significant positive correlations between external exposures (i.e. personal air concentrations of PAHs) and biomarkers (i.e. change in urinary PAH metabolite levels in round 1 and change in breath concentrations of benzene in round 2). The results suggest that firefighters wearing full protective ensembles absorbed combustion products into their bodies. The PAHs most likely entered firefighters' bodies through their skin, with the neck being the primary site of exposure and absorption due to the lower level of dermal protection afforded by hoods. Aromatic hydrocarbons could have been absorbed dermally during firefighting or inhaled during the doffing of gear that was off-gassing contaminants. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Systemic Exposure to PAHs and Benzene in Firefighters Suppressing Controlled Structure Fires

PubMed Central

Fent, Kenneth W.; Eisenberg, Judith; Snawder, John; Sammons, Deborah; Pleil, Joachim D.; Stiegel, Matthew A.; Mueller, Charles; Horn, Gavin P.; Dalton, James

2014-01-01

Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre-exposure levels for round 1. We found statistically significant positive correlations between external exposures (i.e. personal air concentrations of PAHs) and biomarkers (i.e. change in urinary PAH metabolite levels in round 1 and change in breath concentrations of benzene in round 2). The results suggest that firefighters wearing full protective ensembles absorbed combustion products into their bodies. The PAHs most likely entered firefighters’ bodies through their skin, with the neck being the primary site of exposure and absorption due to the lower level of dermal protection afforded by hoods. Aromatic hydrocarbons could have been absorbed dermally during firefighting or inhaled during the doffing of gear that was off-gassing contaminants. PMID:24906357

The external respiration and gas exchange in space missions

NASA Astrophysics Data System (ADS)

Baranov, V. M.; Tikhonov, M. A.; Kotov, A. N.

Literature data and results of our own studies into an effect of micro- and macro-gravity on an external respiration function of man are presented. It is found that in cosmonauts following the 7-366 day space missions there is an enhanced tendency associated with an increased flight duration toward a decrease in the lung volume and breathing mechanics parameters: forced vital capacity of the lungs (FVC) by 5-25 percent, peak inspiratory and expiratory (air) flows (PIF, PEF) by 5-40 percent. A decrease in FVC appears to be explained by a new balance of elastic forces of the lungs, chest and abdomen occuring in microgravity as well as by an increased blood filling and pulmonary hydration. A decline of PIF and PEF is probalbly resulted from antigravitational deconditioning of the respiratory muscles with which a postflight decreased physical performance can in part be associated. The ventilation/perfusion ratios during orthostasis and +G Z and +G X accelerations are estimated. The biophysical nature of developing the absorption atelectases on a combined exposure to accelerations and 100% oxygen breathing is confirmed. A hypothesis that hypervolemia and pulmonary congestion can increase the tendency toward the development of atelectases in space in particular during pure oxygen breathing is suggested. Respiratory physiology problem area which is of interest for space medicine is defined. It is well known that due to present-day technologic progress and accomplishments in applied physiology including applied respiration physiology there currently exist sophisticated technical facilities in operation maintaining the life and professional working capacity of a man in various natural environments: on Earth, under water and in space. By the way, the biomedical involvement in developing and constructing such facilities has enabled an accumulation of a great body of information from experimental studies and full-scale trails to examine the effects of the changed environments both and its individual systems including an external respiration function. In this case, it should be remembered that the external respiration system has some physiological and morphological properties due to which the body systems are particularly subjected to environmental effects. Thus, according to figurative comparison by Evald Veible a contact area of the lungs with an external environment i.e. an alveolar surface is large and equaled approximately to tennis-court size, as the alveolocapillary membrane thickness is negligible and amounts to one fiftieth of a writing-paper sheet [1]. From this it follows that such a fine and highly organized structure must be extremely dependent upon any external exposures including gravitational ones since from the physical viewpoint of physics the lungs represent a quasiconical three-dimensional elastic body suspended in the thoracic cavity and in which there occur the gravity-induced internal tensions incrementing in a base-to-apices direction. As a result of these tensions, in the lungs various physical gradients: hydrostatic, pleural and transpulmonary pressures, pulmonary time constant, vertical gradient of the volume and structure of alveoli, etc. are developed.

Complex deformation associated with anhydrite layers in the Tromsø Basin, SW Barents Sea.

NASA Astrophysics Data System (ADS)

Marfo, George; Olakunle Omosanya, Kamaldeen; Johansen, Ståle Emil; Zervas, Ioannis

2017-04-01

Internal and external deformation associated with salt structures is of prime interest due to their economic importance as hydrocarbon seals, reservoirs, repositories for chemical waste and their implication on drilling. Salt structures are often associated with anhydrites, which may 'cap' or are enclosed within the allochthonous salt structures. Despite their economic importance, the internal and external structures of evaporites remain poorly studied from field and seismic data due to the sparse outcrops of evaporites and poor seismic imaging. The zero-phased, normal polarity, high resolution multiple 2D seismic data, in combination with detailed interpretation of wireline logs provide an excellent study into the salt structures, and offers a good opportunity to investigate the dynamics, geometries and mechanisms driving deformation of internal and external salt layers associated with the Late Carboniferous to Early Permian Salt structures in the Tromsø Basin. The methods include seismic interpretation and the application of multiple seismic attributes to map stratigraphic units and discontinuities. Our results show that the anhydrite layers are marked by high amplitude reflections at the crests and flanks or fully enclosed within the salt diapirs. Crestal and lateral anhydrite caprocks represent external salt structures whilst the entrained anhydrites or stringers are intrasalt structures. Anhydrite caprocks generally show structural styles such as faults and large-scale folds which are harmonic to the top salt structure. In contrast, anhydrite stringers show folds of varying scale, which are harmonic to disharmonic to the top salt structure. Boudins and steeply dipping stringer fragments are also interpreted within the stringers. Caprock deformation is attributed to salt upwelling. Folding and boudinaging of originally horizontal and continuous stringer layers formed from a multiphase superimposed sequence of ductile and brittle deformation in response to complex multi-dimensional salt flow. Internal salt flow involves radial and tangential compression, which leads to dominant fold structures near the margins. Boudins on the lower flanks of the diapir formed due radial extension. Our study further demonstrates that differential geometries exhibited by the different anhydrite groups imply that the mechanisms deforming internal and external salt structures are different. The results from this study are comparable to observations from salt mines, field exposures, scaled physical and numerical models.

Oxidation and the Effects of High Temperature Exposures on Notched Fatigue Life of an Advanced Powder Metallurgy Disk Superalloy

NASA Technical Reports Server (NTRS)

Sudbrack, Chantal K.; Draper, Susan L.; Gorman, Timothy T.; Telesman, Jack; Gab, Timothy P.; Hull, David R.

2012-01-01

Oxidation and the effects of high temperature exposures on notched fatigue life were considered for a powder metallurgy processed supersolvus heat-treated ME3 disk superalloy. The isothermal static oxidation response at 704 C, 760 C, and 815 C was consistent with other chromia forming nickel-based superalloys: a TiO2-Cr2O3 external oxide formed with a branched Al2O3 internal subscale that extended into a recrystallized - dissolution layer. These surface changes can potentially impact disk durability, making layer growth rates important. Growth of the external scales and dissolution layers followed a cubic rate law, while Al2O3 subscales followed a parabolic rate law. Cr- rich M23C6 carbides at the grain boundaries dissolved to help sustain Cr2O3 growth to depths about 12 times thicker than the scale. The effect of prior exposures was examined through notched low cycle fatigue tests performed to failure in air at 704 C. Prior exposures led to pronounced debits of up to 99 % in fatigue life, where fatigue life decreased inversely with exposure time. Exposures that produced roughly equivalent 1 m thick external scales at the various isotherms showed statistically equivalent fatigue lives, establishing that surface damage drives fatigue debit, not exposure temperature. Fractographic evaluation indicated the failure mode for the pre-exposed specimens involved surface crack initiations that shifted with exposure from predominately single intergranular initiations with transgranular propagation to multi-initiations from the cracked external oxide with intergranular propagation. Weakened grain boundaries at the surface resulting from the M23C6 carbide dissolution are partially responsible for the intergranular cracking. Removing the scale and subscale while leaving a layer where M23C6 carbides were dissolved did not lead to a significant fatigue life improvement, however, also removing the M23C6 carbide dissolution layer led to nearly full recovery of life, with a transgranular initiation typical to that observed in unexposed specimens.

Effects of Thermal Exposure on Properties of Al-Li Alloys

NASA Technical Reports Server (NTRS)

Shah, Sandeep; Wells, Douglas; Stanton, William; Lawless, Kirby; Russell, Carolyn; Wagner, John; Domack, Marcia; Babel, Henry; Farahmand, Bahram; Schwab, David;

Corrosion Challenges for the Oil and Gas Industry in the State of Qatar

NASA Astrophysics Data System (ADS)

Johnsen, Roy

In Qatar oil and gas has been produced from onshore fields in more than 70 years, while the first offshore field delivered its first crude oil in 1965. Due to the atmospheric conditions in Qatar with periodically high humidity, high chloride content, dust/sand combined with the temperature variations, external corrosion is a big treat to the installations and connecting infrastructure. Internal corrosion in tubing, piping and process systems is also a challenge due to high H2S content in the hydrocarbon mixture and exposure to corrosive aquifer water. To avoid corrosion different type of mitigations like application of coating, chemical treatment and material selection are important elements. This presentation will review the experiences with corrosion challenges for oil & gas installations in Qatar including some examples of corrosion failures that have been seen.

Crew health

NASA Technical Reports Server (NTRS)

Billica, Roger D.

1992-01-01

Crew health concerns for Space Station Freedom are numerous due to medical hazards from isolation and confinement, internal and external environments, zero gravity effects, occupational exposures, and possible endogenous medical events. The operational crew health program will evolve from existing programs and from life sciences investigations aboard Space Station Freedom to include medical monitoring and certification, medical intervention, health maintenance and countermeasures, psychosocial support, and environmental health monitoring. The knowledge and experience gained regarding crew health issues and needs aboard Space Station Freedom will be used not only to verify requirements and programs for long duration space flight, but also in planning and preparation for Lunar and Mars exploration and colonization.

Years of life lost of inhabitants of rural areas in Poland due to premature mortality caused by external reasons of death 1999-2012.

PubMed

Bryła, Marek; Maniecka-Bryła, Irena; Burzyńska, Monika; Pikala, Małgorzata

2016-12-23

External causes of death are the third most common causes of death, after cardiovascular diseases and malignant neoplasms, in inhabitants of Poland. External causes of death pose the greatest threat to people aged 5-44, which results in a great number of years of life lost. The aim of the study is the analysis of years of life lost due to external causes of death among rural inhabitants in Poland, particularly due to traffic accidents and suicides. The study material included a database created on the basis of 2,100,785 certificates of rural inhabitants in Poland in the period 1999-2012. The SEYLL p (Standard Expected Years of Life Lost per living person) and the SEYLL d (per death) indices were used to determine years of life lost due to external causes of death. Joinpoint models were used to analyze time trends. In the period 1999-2012, 151,037 rural inhabitants died due to external causes, including 27.2% due to traffic accidents and 25.2% due to suicides. In 2012, the SEYLL p was 1,817 per 100,000 males and 298 per 100,000 females. Among males, suicides (SEYLL p = 633 years per 100,000) and traffic accidents (SEYLL p = 473 years per 100,000) contributed to the largest number of years of life lost. Among females, SEYLLp values were: 109 years due to traffic accidents and 69 years due to suicides (per 100,000). Among males, SEYLL p values started to decrease in 2008 at the average annual rate of 3.2%. In the group of females in the period 1999-2012, SEYLL p values were decreasing by 2.4% per year. The decreasing trend of the number of lost years of life due to external causes among rural inhabitants does not apply to suicides among men. The SEYLL p due to this group of causes has been steadily increasing since 1999. Analysis of the years of life lost focuses on the social and economic aspects of premature mortality due to external causes.

Controlling for selection effects in the relationship between child behavior problems and exposure to intimate partner violence.

PubMed

Emery, Clifton R

2011-05-01

This article used the Project on Human Development in Chicago Neighborhoods (PHDCN) data to examine the relationship between exposure to intimate partner violence (IPV) and child behavior problems (externalizing and internalizing), truancy, grade repetition, smoking, drinking, and use of marijuana. Longitudinal data analysis was conducted on 1,816 primary caregivers and their children. Fixed-effects regression models were employed to address concerns with selection bias. IPV was associated with significantly greater internalizing behavior, externalizing behavior, and truancy. Findings from age interaction models suggested that the relationship between IPV and child behavior problems may attenuate as the age of the child at time of exposure increases.

Repeated exposure to high-frequency spanking and child externalizing behavior across the first decade: a moderating role for cumulative risk.

PubMed

MacKenzie, Michael J; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

2014-12-01

This study used the Fragile Families and Child Well-Being Study to examine the effects of repeated exposure to harsh parenting on child externalizing behavior across the first decade of life, and a moderating role for cumulative ecological risk. Maternal report of harsh parenting, defined as high frequency spanking, was assessed at age 1, 3, 5, and 9, along with child externalizing at age 9 (N=2,768). Controlling for gender, race, maternal nativity, and city of residence, we found a cumulative risk index to significantly moderate the effects of repeated harsh parenting on child behavior, with the effects of repeated high-frequency spanking being amplified for those experiencing greater levels of cumulative risk. Harsh parenting, in the form of high frequency spanking, remains a too common experience for children, and results demonstrate that the effects of repeated exposure to harsh parenting across the first decade are amplified for those children already facing the most burden. Copyright © 2014. Published by Elsevier Ltd.

Repeated exposure to high-frequency spanking and child externalizing behavior across the first decade: A moderating role for cumulative risk

PubMed Central

MacKenzie, Michael J.; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

2016-01-01

This study used the Fragile Families and Child Well-being study to examine the effects of repeated exposure to harsh parenting on child externalizing behavior across the first decade of life, and a moderating role for cumulative ecological risk. Maternal report of harsh parenting, defined as high frequency spanking, was assessed at age 1, 3, 5, and 9, along with child externalizing at age 9 (N=2768). Controlling for gender, race, maternal nativity, and city of residence, we found a cumulative risk index to significantly moderate the effects of repeated harsh parenting on child behavior, with the effects of repeated high-frequency spanking being amplified for those experiencing greater levels of cumulative risk. Harsh parenting, in the form of high frequency spanking, remains a too common experience for children, and results demonstrate that the effects of repeated exposure to harsh parenting across the first decade are amplified for those children already facing the most burden. PMID:25465318

Posttraumatic Stress, Family Functioning, and Externalizing in Adolescents Exposed to Violence: A Moderated Mediation Model.

PubMed

Deane, Kyle; Richards, Maryse; Mozley, Michaela; Scott, Darrick; Rice, Catherine; Garbarino, James

2016-09-02

Exposure to community violence disproportionately impacts low-income, minority youth and is associated with posttraumatic stress symptoms and maladaptive adjustment. This study investigates whether posttraumatic stress mediates the relation between exposure to community violence and externalizing symptoms and the moderating role of family cohesion and daily family support in buffering these effects on later externalizing. Low-income, African American 7th-grade students (M age = 12.57 years; N = 254) from high-crime neighborhoods participated in a 2-year longitudinal study measuring the effects of community violence exposure. The students completed questionnaires administered by research staff over 5 consecutive days for each year of the study. Family cohesion and daily family support exhibited a significant buffering effect for several outcomes. Posttraumatic stress significantly mediated the effect of witnessing community violence on subsequent aggression. The strength of these indirect effects depended on level of family cohesion. The findings provide evidence in support of interventions provided at both individual and family levels. Mental health providers working with this population should be aware of the intertwined nature of exposure to community violence, posttraumatic stress, and subsequent maladaptive outcomes.

Therapeutic Ultrasound Enhancement of Drug Delivery to Soft Tissues

NASA Astrophysics Data System (ADS)

Lewis, George; Wang, Peng; Lewis, George; Olbricht, William

2009-04-01

Effects of exposure to 1.58 MHz focused ultrasound on transport of Evans Blue Dye (EBD) in soft tissues are investigated when an external pressure gradient is applied to induce convective flow through the tissue. The magnitude of the external pressure gradient is chosen to simulate conditions in brain parenchyma during convection-enhanced drug delivery (CED) to the brain. EBD uptake and transport are measured in equine brain, avian muscle and agarose brain-mimicking phantoms. Results show that ultrasound enhances EBD uptake and transport, and the greatest enhancement occurs when the external pressure gradient is applied. The results suggest that exposure of the brain parenchyma to ultrasound could enhance penetration of material infused into the brain during CED therapy.

Carotid artery and lower cranial nerve exposure with increasing surgical complexity to the parapharyngeal space.

PubMed

Lemos-Rodriguez, Ana M; Sreenath, Satyan B; Rawal, Rounak B; Overton, Lewis J; Farzal, Zainab; Zanation, Adam M

2017-03-01

To investigate the extent of carotid artery exposure attained, including the identification of the external carotid branches and lower cranial nerves in five sequential external approaches to the parapharyngeal space, and to provide an anatomical algorithm. Anatomical study. Six latex-injected adult cadaver heads were dissected in five consecutive approaches: transcervical approach with submandibular gland removal, posterior extension of the transcervical approach, transcervical approach with parotidectomy, parotidectomy with lateral mandibulotomy, and parotidectomy with mandibulectomy. The degree of carotid artery exposure attained, external carotid branches, and lower cranial nerves visualized was documented. The transcervical approach exposed 1.5 cm (Standard Deviation (SD) 0.5) of internal carotid artery (ICA) and 1.25 cm (SD 0.25) of external carotid artery (ECA). The superior thyroid and facial arteries and cranial nerve XII and XI were identified. The posterior extension exposed 2.9 cm (SD 0.7) of ICA and 2.7 cm (SD 1.0) of ECA. Occipital and ascending pharyngeal arteries were visualized. The transparotid approach exposed 4.0 cm (SD 1.1) of ICA and 3.98 cm (SD 1.8) of ECA. Lateral mandibulotomy exposed the internal maxillary artery, cranial nerve X, the sympathetic trunk, and 4.6 cm (SD 2.4) of ICA. Mandibulectomy allowed for complete ECA exposure, cranial nerve IX, lingual nerve, and 6.9 cm (SD 1.3) of ICA. Approaches for the parapharyngeal space must be based on anatomic and biological patient factors. This study provides a guide for the skull base surgeon for an extended approach based on the desired anatomic exposure. N/A. Laryngoscope, 127:585-591, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Perceived family social support buffers against the effects of exposure to rocket attacks on adolescent depression, aggression, and severe violence.

PubMed

Shahar, Golan; Henrich, Christopher C

2016-02-01

The authors compared the protective effects of 3 sources of perceived social support-from family members, friends, and school personnel-on internalizing and externalizing symptoms in adolescents exposed to rocket attacks. Data were based on 362 Israeli adolescents (median age = 14), chronically exposed to rockets from the Gaza Strip, for whom robust effects of exposure on internalizing and externalizing symptoms were reported during the 2009-2010 period (Henrich & Shahar, 2013). New analyses revealed that perceived family social support assessed in 2009 buffered against the effect of exposure to rocket attacks on depression, aggression, and severe violence during 2009-2010. Findings are consistent with a human-ecological perspective exposure to political violence and encourage the employment of family-based preventive interventions in afflicted areas. (c) 2016 APA, all rights reserved).

Emotion Dysregulation as a Mechanism Linking Stress Exposure to Adolescent Aggressive Behavior

ERIC Educational Resources Information Center

Herts, Kate L.; McLaughlin, Katie A.; Hatzenbuehler, Mark L.

2012-01-01

Exposure to stress is associated with a wide range of internalizing and externalizing problems in adolescents, including aggressive behavior. Extant research examining mechanisms underlying the associations between stress and youth aggression has consistently identified social information processing pathways that are disrupted by exposure to…

Human biomonitoring of chromium and nickel from an experimental exposure to manual metal arc welding fumes of low and high alloyed steel.

PubMed

Bertram, Jens; Brand, Peter; Schettgen, Thomas; Lenz, Klaus; Purrio, Ellwyn; Reisgen, Uwe; Kraus, Thomas

2015-05-01

The uptake and elimination of metals from welding fumes is currently not fully understood. In the Aachen Workplace Simulation Laboratory (AWSL) it is possible to investigate the impact of welding fumes on human subjects under controlled exposure conditions. In this study, the uptake and elimination of chromium or chromium (VI) respectively as well as nickel was studied in subjects after exposure to the emissions of a manual metal arc welding process using low or high alloyed steel. In this present study 12 healthy male non-smokers, who never worked as welders before, were exposed for 6h to welding fumes of a manual metal arc welding process. In a three-fold crossover study design, subjects were exposed in randomized order to either clean air, emissions from welding low alloyed steel, and emissions from welding high alloyed steel. Particle mass concentration of the exposure aerosol was 2.5mg m(-3). The content of chromium and nickel in the air was determined by analysing air filter samples on a high emission scenario. Urine analysis for chromium and nickel was performed before and after exposure using methods of human biomonitoring. There were significantly elevated chromium levels after exposure to welding fumes from high alloyed steel compared to urinary chromium levels before exposure to high alloyed welding fumes, as well as compared to the other exposure scenarios. The mean values increased from 0.27 µg l(-1) to 18.62 µg l(-1). The results were in good agreement with already existing correlations between external and internal exposure (German exposure equivalent for carcinogenic working materials EKA). The variability of urinary chromium levels was high. For urinary nickel no significant changes could be detected at all. Six-hour exposure to 2.5mg m(-3) high alloyed manual metal arc welding fumes lead to elevated urinary chromium levels far higher (7.11-34.16 µg l(-1)) than the German biological exposure reference value (BAR) of 0.6 µg l(-1) directly after exposure. On the other hand mean urinary nickel concentrations slightly increased, but did not exceed background levels due to lower bioavailability. We could underline with our single exposure experiment that a welding work related chromium exposure can be measured immediately after the work shift, while the same is not possible for nickel exposure due to lower nickel bioavailability. The data provide useful information for real occupational welding work places. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

A nested case-control study of leukemia mortality and ionizing radiation at the Portsmouth Naval Shipyard.

PubMed

Kubale, Travis L; Daniels, Robert D; Yiin, James H; Couch, James; Schubauer-Berigan, Mary K; Kinnes, Gregory M; Silver, Sharon R; Nowlin, Susan J; Chen, Pi-Hsueh

2005-12-01

A nested case-control study using conditional logistic regression was conducted to evaluate the exposure-response relationship between external ionizing radiation exposure and leukemia mortality among civilian workers at the Portsmouth Naval Shipyard (PNS), Kittery, Maine. The PNS civilian workers received occupational radiation exposure while performing construction, overhaul, repair and refueling activities on nuclear-powered submarines. The study age-matched 115 leukemia deaths with 460 controls selected from a cohort of 37,853 civilian workers employed at PNS between 1952 and 1992. In addition to radiation doses received in the workplace, a secondary analysis incorporating doses from work-related medical X rays and other occupational radiation exposures was conducted. A significant positive association was found between leukemia mortality and external radiation exposure, adjusting for gender, radiation worker status, and solvent exposure duration (OR = 1.08 at 10 mSv of exposure; 95% CI = 1.01, 1.16). Solvent exposure (including benzene and carbon tetrachloride) was also significantly associated with leukemia mortality adjusting for radiation dose, radiation worker status, and gender. Incorporating doses from work-related medical X rays did not change the estimated leukemia risk per unit of dose.

Thermal Exposure Effects on Properties of Al-Li Alloy Plate Products

NASA Technical Reports Server (NTRS)

Shah, Sandeep; Wells, Douglas; Wagner, John; Babel, Henry

2002-01-01

Aluminum-Lithium (AL-Li) alloys offer significant performance benefits for aerospace structural applications due to their higher specific properties compared with conventional aluminum alloys. For example, the application of an Al-Li alloy to the space shuttle external cryogenic fuel tank contributed to the weight savings that enabled successful deployment of International Space Station components. The composition and heat treatment of this alloy were optimized specifically for strength-toughness considerations for an expendable cryogenic tank. Time dependent properties related to reliability, such as thermal stability, fatigue, and corrosion, will be of significant interest when materials are evaluated for a reusable cryotank structure. As most aerospace structural hardware is weight sensitive, a reusable cryotank will be designed to the limits of the materials mechanical properties. Therefore, this effort was designed to establish the effects of thermal exposure on the mechanical properties and microstructure of one relatively production mature alloy and two developmental alloys C458 and L277. Tensile and fracture toughness behavior was evaluated after exposure to temperatures as high as 3oooF for up to IO00 hrs. Microstructural changes were also evaluated to correlate with the observed data trends. The ambient temperature parent metal data showed an increase in strength and reduction in elongation after exposure at lower temperatures. Strength reached a peak with intermediate temperature exposure followed by a decrease at highest exposure temperature. Characterizing the effect of thermal exposure on the properties of Al-Li alloys is important to defining a service limiting temperature, exposure time, and end-of-life properties.

Sex-Dependent Effects of Developmental Lead Exposure on the Brain.

PubMed

Singh, Garima; Singh, Vikrant; Sobolewski, Marissa; Cory-Slechta, Deborah A; Schneider, Jay S

2018-01-01

The role of sex as an effect modifier of developmental lead (Pb) exposure has until recently received little attention. Lead exposure in early life can affect brain development with persisting influences on cognitive and behavioral functioning, as well as, elevated risks for developing a variety of diseases and disorders in later life. Although both sexes are affected by Pb exposure, the incidence, manifestation, and severity of outcomes appears to differ in males and females. Results from epidemiologic and animal studies indicate significant effect modification by sex, however, the results are not consistent across studies. Unfortunately, only a limited number of human epidemiological studies have included both sexes in independent outcome analyses limiting our ability to draw definitive conclusions regarding sex-differentiated outcomes. Additionally, due to various methodological differences across studies, there is still not a good mechanistic understanding of the molecular effects of lead on the brain and the factors that influence differential responses to Pb based on sex. In this review, focused on prenatal and postnatal Pb exposures in humans and animal models, we discuss current literature supporting sex differences in outcomes in response to Pb exposure and explore some of the ideas regarding potential molecular mechanisms that may contribute to sex-related differences in outcomes from developmental Pb exposure. The sex-dependent variability in outcomes from developmental Pb exposure may arise from a combination of complex factors, including, but not limited to, intrinsic sex-specific molecular/genetic mechanisms and external risk factors including sex-specific responses to environmental stressors which may act through shared epigenetic pathways to influence the genome and behavioral output.

Sex-Dependent Effects of Developmental Lead Exposure on the Brain

PubMed Central

Singh, Garima; Singh, Vikrant; Sobolewski, Marissa; Cory-Slechta, Deborah A.; Schneider, Jay S.

2018-01-01

The role of sex as an effect modifier of developmental lead (Pb) exposure has until recently received little attention. Lead exposure in early life can affect brain development with persisting influences on cognitive and behavioral functioning, as well as, elevated risks for developing a variety of diseases and disorders in later life. Although both sexes are affected by Pb exposure, the incidence, manifestation, and severity of outcomes appears to differ in males and females. Results from epidemiologic and animal studies indicate significant effect modification by sex, however, the results are not consistent across studies. Unfortunately, only a limited number of human epidemiological studies have included both sexes in independent outcome analyses limiting our ability to draw definitive conclusions regarding sex-differentiated outcomes. Additionally, due to various methodological differences across studies, there is still not a good mechanistic understanding of the molecular effects of lead on the brain and the factors that influence differential responses to Pb based on sex. In this review, focused on prenatal and postnatal Pb exposures in humans and animal models, we discuss current literature supporting sex differences in outcomes in response to Pb exposure and explore some of the ideas regarding potential molecular mechanisms that may contribute to sex-related differences in outcomes from developmental Pb exposure. The sex-dependent variability in outcomes from developmental Pb exposure may arise from a combination of complex factors, including, but not limited to, intrinsic sex-specific molecular/genetic mechanisms and external risk factors including sex-specific responses to environmental stressors which may act through shared epigenetic pathways to influence the genome and behavioral output. PMID:29662502

Fine particulate matter (PM2.5) air pollution and selected causes of postneonatal infant mortality in California.

PubMed

Woodruff, Tracey J; Parker, Jennifer D; Schoendorf, Kenneth C

2006-05-01

Studies suggest that airborne particulate matter (PM) may be associated with postneonatal infant mortality, particularly with respiratory causes and sudden infant death syndrome (SIDS). To further explore this issue, we examined the relationship between long-term exposure to fine PM air pollution and postneonatal infant mortality in California. We linked monitoring data for PM

Physical family violence and externalizing and internalizing behaviors among children and adolescents.

PubMed

Renner, Lynette M; Boel-Studt, Shamra

2017-01-01

Family violence has been associated with various negative outcomes among children and adolescents. Yet, less is known about how unique forms of physical family violence contribute to externalizing and internalizing behaviors based on a child's developmental stage. Using data from the Illinois Families Study and administrative Child Protective Services data, we explored the relation between 3 types of physical family violence victimization and externalizing and internalizing behaviors among a sample of 2,402 children and adolescents. After including parent and family level covariates in Poisson regressions, we found that a unique form of family violence victimization was associated with increased externalizing behaviors among children at each age group: exposure to physical intimate partner violence (IPV) among children ages 3-5, exposure to the physical abuse of a sibling among children ages 6-12, and child physical abuse among adolescents ages 13-18. No form of physical family violence was significantly associated with internalizing behaviors for children in any age group. Including exposure to the child maltreatment of a sibling is crucial when attempting to contextualize children's responses to family violence and providing comprehensive services in an effort to enhance the well-being of all children in a family. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Health effects from fallout.

PubMed

Gilbert, Ethel S; Land, Charles E; Simon, Steven L

2002-05-01

This paper primarily discusses health effects that have resulted from exposures received as a result of above-ground nuclear tests, with emphasis on thyroid disease from exposure to 131I and leukemia and solid cancers from low dose rate external and internal exposure. Results of epidemiological studies of fallout exposures in the Marshall Islands and from the Nevada Test Site are summarized, and studies of persons with exposures similar to those from fallout are briefly reviewed (including patients exposed to 131I for medical reasons and workers exposed externally at low doses and low dose rates). Promising new studies of populations exposed in countries of the former Soviet Union are also discussed and include persons living near the Semipalatinsk Test Site in Kazakhstan, persons exposed as a result of the Chernobyl accident, and persons exposed as a result of operations of the Mayak Nuclear Plant in the Russian Federation. Very preliminary estimates of cancer risks from fallout doses received by the United States population are presented.

MOVING FROM EXTERNAL EXPOSURE CONCENTRATION TO INTERNAL DOSE: DURATION EXTRAPOLATION BASED ON PHYSIOLOGICALLY-BASED PHARMACOKINETIC-MODEL DERIVED ESTIMATES OF INTERNAL DOSE

EPA Science Inventory

The potential human health risk(s) from exposure to chemicals under conditions for which adequate human or animal data are not available must frequently be assessed. Exposure scenario is particularly important for the acute neurotoxic effects of volatile organic compounds (VOCs)...

Exposure to Domestic and Community Violence in a Nonrisk Sample: Associations with Child Functioning

ERIC Educational Resources Information Center

Malik, Neena M.

2008-01-01

Limited data exist on the unique, additive, and interactive effects of exposure to domestic and community violence on children's functioning, particularly in community samples. This study examined relations between children's violence exposure, at home and in the community, and symptoms of externalizing and internalizing problems. Parents reported…

Collective Efficacy and the Contingent Consequences of Exposure to Life-Threatening Violence1

PubMed Central

Browning, Christopher R.; Gardner, Margo; Maimon, David; Brooks-Gunn, Jeanne

2014-01-01

Neighborhood research has increasingly emphasized the potential for contextual characteristics to moderate the effects of youths’ experiences on their outcomes. Drawing on collective efficacy theory, we examine the variable consequences of youths’ exposures to life threatening violence across neighborhoods. We argue that strong community normative orientations supporting the control of violence diminish the negative effect of exposure to severe violence on subsequent mental health among urban youth. We also consider the extent to which the consequences of exposure to violence vary by gender. Employing data from the Project on Human Development in Chicago Neighborhoods, we estimate a series of multivariate, multilevel linear models of internalizing and externalizing symptoms. Results indicate that, for girls, exposure to life threatening violence (witnessing someone being attacked with a weapon or shot) increases both internalizing and externalizing symptoms. However, this effect achieves statistical significance only for girls who reside in lower collective efficacy neighborhoods. For boys, our analyses offered weaker evidence of violence exposure effects on mental health. Implications for research on the social context of mental health are discussed. PMID:24842460

Parsing the Effects Violence Exposure in Early Childhood: Modeling Developmental Pathways

PubMed Central

Carter, Alice S.; Ford, Julian D.

2012-01-01

Objective To prospectively examine pathways from early childhood violence exposure and trauma-related symptoms to school-age emotional health. Methods A longitudinal, birth cohort (N = 437) was assessed with parent reports of lifetime violence exposure and trauma-related symptoms at 3 years of age and later, internalizing and externalizing symptoms, and social competence at school age. Results Early family and neighborhood violence correlated significantly with early trauma-related symptoms and also significantly predicted school-age internalizing and externalizing symptoms and poorer competence, independent of sociodemographic risk and past-year violence exposure. Longitudinal pathways were significantly mediated by arousal and avoidance symptoms at 3 years of age, which increased risk for clinically significant emotional problems and lower competence at school age (adjusted odds ratios = 3.1–6.1, p < 0.01). Conclusions Trauma-related symptoms may mediate developmental pathways from early violence exposure to later emotional health. Interventions that prevent or reduce early trauma-related symptoms may ameliorate the long-term deleterious impact of violence exposure. PMID:21903730

Observed differences in upper extremity forces, muscle efforts, postures, velocities and accelerations across computer activities in a field study of office workers.

PubMed

Bruno Garza, J L; Eijckelhof, B H W; Johnson, P W; Raina, S M; Rynell, P W; Huysmans, M A; van Dieën, J H; van der Beek, A J; Blatter, B M; Dennerlein, J T

2012-01-01

This study, a part of the PRedicting Occupational biomechanics in OFfice workers (PROOF) study, investigated whether there are differences in field-measured forces, muscle efforts, postures, velocities and accelerations across computer activities. These parameters were measured continuously for 120 office workers performing their own work for two hours each. There were differences in nearly all forces, muscle efforts, postures, velocities and accelerations across keyboard, mouse and idle activities. Keyboard activities showed a 50% increase in the median right trapezius muscle effort when compared to mouse activities. Median shoulder rotation changed from 25 degrees internal rotation during keyboard use to 15 degrees external rotation during mouse use. Only keyboard use was associated with median ulnar deviations greater than 5 degrees. Idle activities led to the greatest variability observed in all muscle efforts and postures measured. In future studies, measurements of computer activities could be used to provide information on the physical exposures experienced during computer use. Practitioner Summary: Computer users may develop musculoskeletal disorders due to their force, muscle effort, posture and wrist velocity and acceleration exposures during computer use. We report that many physical exposures are different across computer activities. This information may be used to estimate physical exposures based on patterns of computer activities over time.

Exposure to domestic and community violence in a nonrisk sample: associations with child functioning.

PubMed

Malik, Neena M

2008-04-01

Limited data exist on the unique, additive, and interactive effects of exposure to domestic and community violence on children's functioning, particularly in community samples. This study examined relations between children's violence exposure, at home and in the community, and symptoms of externalizing and internalizing problems. Parents reported on domestic violence in the home, and children reported on community violence. Concurrent child functioning was measured through parent and teacher reports on the Child Behavior Checklist (CBCL) and child self-reports on the Children's Depression Inventory. A multi-ethnic sample of 117 children, aged 8 to 12 years, and their parents and teachers participated. Community violence was related to all measures of children's adjustment, whereas exposure to domestic violence was related only to CBCL externalizing problems. Teacher reports of child aggression were predicted by child age, community violence, and the interaction of community and domestic violence. Implications for research and clinical intervention are discussed.

Exposure Factors Handbook - 2009 Update (External Review ...

EPA Pesticide Factsheets

The mission of National Center for Environmental Assessment (NCEA) of EPA's Office of Research and Development is to provide guidance and risk assessments aimed at protecting human health and the environment. To accomplish this mission, NCEA works to develop and improve the models, databases, tools, assumptions, and extrapolations used in risk assessments. This handbook is a tool developed by NCEA aimed at refining the assumptions used in exposure assessments and reducing uncertainty. This handbook was first published in 1989 and updated in 1997 to provide statistical data on the various human factors used in assessing exposure. This revised version of the handbook provides the up-to-date data on these exposure factors. The recommended values are based solely on our interpretations of the available data. In many situations different values may be appropriate to use in consideration of policy, precedent or other factors. External Review Draft

Childhood Poverty, Cumulative Risk Exposure, and Mental Health in Emerging Adults

PubMed Central

Evans, Gary W.; Cassells, Rochelle C.

2014-01-01

One out of four American children are born into poverty, but little is known about the long-term, mental health implications of early deprivation. The more time in poverty from birth-age-9, the worse mental health as emerging adults (n = 196, M = 17.30 years, 53% male). These results maintain independently of concurrent, adult income levels for self-reported externalizing symptoms and a standard learned helplessness behavioral protocol, but internalizing symptoms were unaffected by childhood poverty. We then demonstrate that part of the reason why early poverty exposure is harmful to mental health among emerging adults is because of elevated cumulative risk exposure assessed at age 13. The significant, prospective, longitudinal relations between early childhood poverty and externalizing symptoms plus learned helplessness behavior are mediated, in part, by exposure to a confluence of psychosocial (violence, family turmoil, child separation from family) and physical (noise, crowding, substandard housing) risk factors during adolescence. PMID:26609499

Early life trauma exposure and stress sensitivity in young children.

PubMed

Grasso, Damion J; Ford, Julian D; Briggs-Gowan, Margaret J

2013-01-01

The current study replicates and extends work with adults that highlights the relationship between trauma exposure and distress in response to subsequent, nontraumatic life stressors. The sample included 213 2-4-year-old children in which 64.3% had a history of potential trauma exposure. Children were categorized into 4 groups based on trauma history and current life stress. In a multivariate analysis of variance, trauma-exposed children with current life stressors had elevated internalizing and externalizing problems compared with trauma-exposed children without current stress and nontrauma-exposed children with and without current stressors. The trauma-exposed groups with or without current stressors did not differ on posttraumatic stress disorder symptom severity. Accounting for number of traumatic events did not change these results. These findings suggest that early life trauma exposure may sensitize young children and place them at risk for internalizing or externalizing problems when exposed to subsequent, nontraumatic life stressors.

Long-term measurements of residential radon, thoron, and thoron progeny concentrations around the Chhatrapur placer deposit, a high background radiation area in Odisha, India.

PubMed

Omori, Yasutaka; Prasad, Ganesh; Sorimachi, Atsuyuki; Sahoo, Sarata Kumar; Ishikawa, Tetsuo; Vidya Sagar, Devulapalli; Ramola, Rakesh Chand; Tokonami, Shinji

2016-10-01

The Chhatrapur placer deposit is found in a high background radiation area which has been recently identified on the southeastern coast of India. Previously, some geochemical studies of this area were carried out to assess external dose from radionuclides-bearing heavy mineral sands. In this study, radon, thoron and thoron progeny concentrations were measured in about 100 dwellings during three seasons (autumn-winter, summer, and rainy) in a 10- to 12-month period and annual doses due to inhalation of them were evaluated. The measurements were made by passive-type radon-thoron discriminative detectors and thoron progeny detectors in which solid state nuclear track detectors were deployed. The results show that radon and thoron concentrations differ by one order of magnitude depending on exposure periods, while thoron progeny concentration is nearly constant throughout the year. Since thorium-rich sand is distributed in the studied area, exposure to thoron is equal to, or exceeds, exposure to radon and is not negligible for dose evaluation. Based on the measurements, doses due to inhalation of radon and thoron are evaluated as 0.1-1.6 mSv y -1 and 0.2-3.8 mSv y -1 , respectively. The total dose is 0.8-4.6 mSv y -1 , which is the same order of magnitude as the worldwide value. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adaptive plasticity in speech perception: Effects of external information and internal predictions.

PubMed

Guediche, Sara; Fiez, Julie A; Holt, Lori L

2016-07-01

When listeners encounter speech under adverse listening conditions, adaptive adjustments in perception can improve comprehension over time. In some cases, these adaptive changes require the presence of external information that disambiguates the distorted speech signals, whereas in other cases mere exposure is sufficient. Both external (e.g., written feedback) and internal (e.g., prior word knowledge) sources of information can be used to generate predictions about the correct mapping of a distorted speech signal. We hypothesize that these predictions provide a basis for determining the discrepancy between the expected and actual speech signal that can be used to guide adaptive changes in perception. This study provides the first empirical investigation that manipulates external and internal factors through (a) the availability of explicit external disambiguating information via the presence or absence of postresponse orthographic information paired with a repetition of the degraded stimulus, and (b) the accuracy of internally generated predictions; an acoustic distortion is introduced either abruptly or incrementally. The results demonstrate that the impact of external information on adaptive plasticity is contingent upon whether the intelligibility of the stimuli permits accurate internally generated predictions during exposure. External information sources enhance adaptive plasticity only when input signals are severely degraded and cannot reliably access internal predictions. This is consistent with a computational framework for adaptive plasticity in which error-driven supervised learning relies on the ability to compute sensory prediction error signals from both internal and external sources of information. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Adaptive plasticity in speech perception: effects of external information and internal predictions

PubMed Central

Guediche, Sara; Fiez, Julie A.; Holt, Lori L.

2016-01-01

When listeners encounter speech under adverse listening conditions, adaptive adjustments in perception can improve comprehension over time. In some cases, these adaptive changes require the presence of external information that disambiguates the distorted speech signals, whereas in other cases mere exposure is sufficient. Both external (e.g. written feedback) and internal (e.g., prior word knowledge) sources of information can be used to generate predictions about the correct mapping of a distorted speech signal. We hypothesize that these predictions provide a basis for determining the discrepancy between the expected and actual speech signal that can be used to guide adaptive changes in perception. This study provides the first empirical investigation that manipulates external and internal factors through 1) the availability of explicit external disambiguating information via the presence or absence of post-response orthographic information paired with a repetition of the degraded stimulus, and 2) the accuracy of internally-generated predictions; an acoustic distortion is introduced either abruptly or incrementally. The results demonstrate that the impact of external information on adaptive plasticity is contingent upon whether the intelligibility of the stimuli permits accurate internally-generated predictions during exposure. External information sources enhance adaptive plasticity only when input signals are severely degraded and cannot reliably access internal predictions. This is consistent with a computational framework for adaptive plasticity in which error-driven supervised learning relies on the ability to compute sensory prediction error signals from both internal and external sources of information. PMID:26854531

How Sensors Might Help Define the External Exposome.

PubMed

Loh, Miranda; Sarigiannis, Dimosthenis; Gotti, Alberto; Karakitsios, Spyros; Pronk, Anjoeka; Kuijpers, Eelco; Annesi-Maesano, Isabella; Baiz, Nour; Madureira, Joana; Oliveira Fernandes, Eduardo; Jerrett, Michael; Cherrie, John W

2017-04-18

The advent of the exposome concept, the advancement of mobile technology, sensors, and the "internet of things" bring exciting opportunities to exposure science. Smartphone apps, wireless devices, the downsizing of monitoring technologies, along with lower costs for such equipment makes it possible for various aspects of exposure to be measured more easily and frequently. We discuss possibilities and lay out several criteria for using smart technologies for external exposome studies. Smart technologies are evolving quickly, and while they provide great promise for advancing exposure science, many are still in developmental stages and their use in epidemiology and risk studies must be carefully considered. The most useable technologies for exposure studies at this time relate to gathering exposure-factor data, such as location and activities. Development of some environmental sensors (e.g., for some air pollutants, noise, UV) is moving towards making the use of these more reliable and accessible to research studies. The possibility of accessing such an unprecedented amount of personal data also comes with various limitations and challenges, which are discussed. The advantage of improving the collection of long term exposure factor data is that this can be combined with more "traditional" measurement data to model exposures to numerous environmental factors.

How Sensors Might Help Define the External Exposome

PubMed Central

Loh, Miranda; Sarigiannis, Dimosthenis; Gotti, Alberto; Karakitsios, Spyros; Pronk, Anjoeka; Kuijpers, Eelco; Annesi-Maesano, Isabella; Baiz, Nour; Madureira, Joana; Oliveira Fernandes, Eduardo; Jerrett, Michael; Cherrie, John W.

2017-01-01

The advent of the exposome concept, the advancement of mobile technology, sensors, and the “internet of things” bring exciting opportunities to exposure science. Smartphone apps, wireless devices, the downsizing of monitoring technologies, along with lower costs for such equipment makes it possible for various aspects of exposure to be measured more easily and frequently. We discuss possibilities and lay out several criteria for using smart technologies for external exposome studies. Smart technologies are evolving quickly, and while they provide great promise for advancing exposure science, many are still in developmental stages and their use in epidemiology and risk studies must be carefully considered. The most useable technologies for exposure studies at this time relate to gathering exposure-factor data, such as location and activities. Development of some environmental sensors (e.g., for some air pollutants, noise, UV) is moving towards making the use of these more reliable and accessible to research studies. The possibility of accessing such an unprecedented amount of personal data also comes with various limitations and challenges, which are discussed. The advantage of improving the collection of long term exposure factor data is that this can be combined with more “traditional” measurement data to model exposures to numerous environmental factors. PMID:28420222

3T magnetic resonance imaging testing of externally programmable shunt valves

PubMed Central

Zabramski, Joseph M.; Preul, Mark C.; Debbins, Josef; McCusker, Daniel J.

2012-01-01

Background: Exposure of externally programmable shunt-valves (EPS-valves) to magnetic resonance imaging (MRI) may lead to unexpected changes in shunt settings, or affect the ability to reprogram the valve. We undertook this study to examine the effect of exposure to a 3T MRI on a group of widely used EPS-valves. Methods: Evaluations were performed on first generation EPS-valves (those without a locking mechanism to prevent changes in shunt settings by external magnets other than the programmer) and second generation EPS-valves (those with a locking mechanisms). Fifteen new shunt-valves were divided into five groups of three identical valves each, and then exposed to a series of six simulated MRI scans. After each of the exposures, the valves were evaluated to determine if the valve settings had changed, and whether the valves could be reprogrammed. The study produced 18 evaluations for each line of shunt-valves. Results: Exposure of the first generation EPS-valves to a 3T magnetic field resulted in frequent changes in the valve settings; however, all valves retained their ability to be reprogrammed. Repeated exposure of the second generation EPS-valves has no effect on shunt valve settings, and all valves retained their ability to be interrogated and reprogrammed. Conclusions: Second generation EPS-valves with locking mechanisms can be safely exposed to repeated 3T MRI systems, without evidence that shunt settings will change. The exposure of the first generation EPS-valves to 3T MRI results in frequent changes in shunt settings that necessitate re-evaluation soon after MRI to avoid complications. PMID:22937481

Effects of gestational exposure to 1.95-GHz W-CDMA signals for IMT-2000 cellular phones: Lack of embryotoxicity and teratogenicity in rats.

PubMed

Ogawa, Kumiko; Nabae, Kyoko; Wang, Jianqing; Wake, Kanako; Watanabe, So-ichi; Kawabe, Mayumi; Fujiwara, Osamu; Takahashi, Satoru; Ichihara, Toshio; Tamano, Seiko; Shirai, Tomoyuki

2009-04-01

The present study was designed to evaluate whether gestational exposure to an EMF targeting the head region, similar to that from cellular phones, might affect embryogenesis in rats. A 1.95-GHz wide-band code division multiple access (W-CDMA) signal, which is one applied for the International Mobile Telecommunication 2000 (IMT-2000) system and used for the freedom of mobile multimedia access (FOMA), was employed for exposure to the heads of four groups of pregnant CD(SD) IGS rats (20 per group) for gestational days 7-17. The exposure was performed for 90 min/day in the morning. The spatial average specific absorption rate (SAR) for individual brains was designed to be 0.67 and 2.0 W/kg with peak brain SARs of 3.1 and 7.0 W/kg for low (group 3) and high (group 4) exposures, respectively, and a whole-body average SAR less than 0.4 W/kg so as not to cause thermal effects due to temperature elevation. Control and sham exposure groups were also included. At gestational day 20, all dams were killed and fetuses were taken out by cesarean section. There were no differences in maternal body weight gain. No adverse effects of EMF exposure were observed on any reproductive and embryotoxic parameters such as number of live (243-271 fetuses), dead or resorbed embryos, placental weights, sex ratios, weights or external, visceral or skeletal abnormalities of live fetuses. (c) 2008 Wiley-Liss, Inc.

Salivary cortisol reactivity in preschoolers is associated with hair cortisol and behavioral problems.

PubMed

Kao, Katie; Doan, Stacey N; St John, Ashley M; Meyer, Jerrold S; Tarullo, Amanda R

2018-01-01

The interplay between children's cortisol reactivity to challenge and cumulative cortisol exposure is not well understood. Examining the role of cortisol reactivity in early childhood may elucidate biological mechanisms that contribute to children's chronic physiological stress and behavioral dysregulation. In a sample of 65 preschool-aged children, we examined the relation between children's salivary cortisol reactivity to challenging tasks and their hair cortisol concentration (HCC). While both are biomarkers of the hypothalamic-pituitary-adrenal (HPA) axis, salivary cortisol reactivity reflects an acute cortisol response to a stressor and HCC reflects cumulative cortisol exposure. In addition, we examined the relations of these stress biomarkers with internalizing and externalizing problems. Salivary cortisol reactivity was associated with higher HCC and with increased externalizing behaviors. Child HCC also was positively correlated with parent HCC. Results highlight the contributions of salivary cortisol reactivity to children's cumulative cortisol exposure, which may add to their biological risk for health problems later. The observed association between externalizing problems and salivary cortisol reactivity indicates concordances between dysregulated behavioral reactions and dysregulated cortisol responses to challenges. The finding that salivary cortisol reactivity to challenge in early childhood plays a role in children's cumulative cortisol exposure and behavioral development suggests pathways through which cortisol reactivity may influence long-term physical and mental health.

Potential hazard due to induced radioactivity secondary to radiotherapy: the report of task group 136 of the American Association of Physicists in Medicine.

PubMed

Thomadsen, Bruce; Nath, Ravinder; Bateman, Fred B; Farr, Jonathan; Glisson, Cal; Islam, Mohammad K; LaFrance, Terry; Moore, Mary E; George Xu, X; Yudelev, Mark

2014-11-01

External-beam radiation therapy mostly uses high-energy photons (x-rays) produced by medical accelerators, but many facilities now use proton beams, and a few use fast-neutron beams. High-energy photons offer several advantages over lower-energy photons in terms of better dose distributions for deep-seated tumors, lower skin dose, less sensitivity to tissue heterogeneities, etc. However, for beams operating at or above 10 MV, some of the materials in the accelerator room and the radiotherapy patient become radioactive due primarily to photonuclear reactions and neutron capture, exposing therapy staff and patients to unwanted radiation dose. Some recent advances in radiotherapy technology require treatments using a higher number of monitor units and monitor-unit rates for the same delivered dose, and compared to the conventional treatment techniques and fractionation schemes, the activation dose to personnel can be substantially higher. Radiotherapy treatments with proton and neutron beams all result in activated materials in the treatment room. In this report, the authors review critically the published literature on radiation exposures from induced radioactivity in radiotherapy. They conclude that the additional exposure to the patient due to induced radioactivity is negligible compared to the overall radiation exposure as a part of the treatment. The additional exposure to the staff due to induced activity from photon beams is small at an estimated level of about 1 to 2 mSv y. This is well below the allowed occupational exposure limits. Therefore, the potential hazard to staff from induced radioactivity in the use of high-energy x-rays is considered to be low, and no specific actions are considered necessary or mandatory. However, in the spirit of the "As Low as Reasonably Achievable (ALARA)" program, some reasonable steps are recommended that can be taken to reduce this small exposure to an even lower level. The dose reduction strategies suggested should be followed only if these actions are considered reasonable and practical in the individual clinics. Therapists working with proton beam and neutron beam units handle treatment devices that do become radioactive, and they should wear extremity monitors and make handling apertures and boluses their last task upon entering the room following treatment. Personnel doses from neutron-beam units can approach regulatory limits depending on the number of patients and beams, and strategies to reduce doses should be followed.

[Trend in inequalities in mortality due to external causes among the municipalities of Antioquia (Colombia)].

PubMed

Caicedo-Velásquez, Beatriz; Álvarez-Castaño, Luz Stella; Marí-Dell'Olmo, Marc; Borrell, Carme

2016-01-01

To analyse the trend in inequalities in mortality due to external causes among municipalities in Antioquia, department of Colombia, from 2000 to 2010, and its association with socioeconomic conditions. External causes included violent deaths, such as homicides, suicides and traffic accidents, among others. Ecological design of mortality trends, with the 125 municipalities of Antioquia as the unit of analysis. The age-adjusted smoothed standardized mortality ratio (SMR) was estimated for each of the municipalities by using an empirical Bayesian model. Differences in the SMR between the poorest and least poor municipalities were estimated by using a two-level hierarchical model (level-1: year, level-2: municipality). Mortality due to external causes showed a downward trend in the department in the period under review, although the situation was not similar in all municipalities. The findings showed that the risk of death from external causes significantly increased in poor and underdeveloped municipalities. Intervention is required through policies that take into account local differences in mortality due to external causes. Copyright © 2016 SESPAS. Published by Elsevier Espana. All rights reserved.

Occupational external exposure to ionising radiation in France (2005-2011).

PubMed

Feuardent, J; Scanff, P; Crescini, D; Rannou, A

2013-12-01

The Institute for Radiological Protection and Nuclear Safety (IRSN) produces the French annual report on occupational exposure to ionising radiation, collecting all national data and aggregating the results according to a unique activity classification expected to be shared by all involved in personal dosimetric monitoring (employers, external dosimetry services and IRSN). Nearly 344,000 monitored workers were counted in France in 2011, with a collective dose of 64.24 man.Sv. The average annual dose (as calculated over the number of measurably exposed workers) differed among the main activity fields: 0.54 mSv in medical and veterinary activities, 1.18 mSv in the nuclear field, 1.60 mSv in non-nuclear industry and 0.47 mSv in research activities. Because of improved knowledge about worker activities, the results for year 2011 are detailed per activity sectors in each field. Lasting limitations prevent from having complete and reliable worker activity information. Solutions are considered to reduce the inaccuracy in the annually published statistics. The evolution of occupational external exposure to ionising radiation from 2005 to 2011 in France is then presented for the main activity fields.

Developmental Pathways from Prenatal Tobacco and Stress Exposure to Behavioral Disinhibition

PubMed Central

Clark, C.A.C.; Espy, K.A.; Wakschlag, L.

2016-01-01

Prenatal tobacco exposure (PTE) and prenatal stress exposure (PSE) each have been linked to externalizing behavior, although their effects generally have been considered in isolation. Here, we aimed to characterize the joint or interactive roles of PTE and PSE in early developmental pathways to behavioral disinhibition, a profile of cognitive and behavioral under-control that presages severe externalizing behavior. As part of a prospective, longitudinal study, 296 children were assessed at a mean age of 5 years. Exposures were assessed via repeated interviews across the prenatal period and bioassays of cotinine were obtained. Behavioral disinhibition was assessed using temperament measures in infancy, performance-based executive control tasks and measures of disruptive and inattentive behavior. PSE was associated with a higher probability of difficult temperament in infancy. Each exposure independently predicted poorer executive control at age 5 years. Difficult temperament and executive control difficulties in turn predicted elevated levels of disruptive behavior, although links from PTE and PSE to parent-reported attention problems were less robust. Children who experienced these prenatal exposures in conjunction with higher postnatal stress exposure showed the lowest executive control and highest levels of disruptive behavior. Findings highlight the compounding adverse impact of PTE and PSE on children’s behavioral trajectories. Given their high concordance, prenatal health campaigns should target these exposures in tandem. PMID:26628107

Measurement of the surface charge accumulation using anodic aluminum oxide(AAO) structure in an inductively coupled plasma

NASA Astrophysics Data System (ADS)

Park, Ji-Hwan; Oh, Seung-Ju; Lee, Hyo-Chang; Kim, Yu-Sin; Kim, Young-Cheol; Kim, June Young; Ha, Chang-Seoung; Kwon, Soon-Ho; Lee, Jung-Joong; Chung, Chin-Wook

2014-10-01

As the critical dimension of the nano-device shrinks, an undesired etch profile occurs during plasma etch process. One of the reasons is the local electric field due to the surface charge accumulation. To demonstrate the surface charge accumulation, an anodic aluminum oxide (AAO) membrane which has high aspect ratio is used. The potential difference between top electrode and bottom electrode in an anodic aluminum oxide contact structure is measured during inductively coupled plasma exposure. The voltage difference is changed with external discharge conditions, such as gas pressure, input power, and gas species and the result is analyzed with the measured plasma parameters.

The Effect of X-Irradiation on Goldfish: I. The Effect of X-Irradiation on Survival and Susceptibility of the Goldfish, Carassius auratus, to Infection by Aeromonas salmonicida and Gyrodactylus spp.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shechmeister, I. L.; Watson, L. J.; Cole, V. W.

1962-01-01

Graded doses (l00 to l0000 r) of whole-body x radiation were administered to goldfish, Carassius auratus. The x ray LD/sub 50(30)/ was found to be 2315 r. Survival time decreased with increase in x-ray dose. Exposure to 100 r resulted in 100% mortality in 363 days; all fish exposed to l0,000 r succumbed in 11 to 14 days. Gross pathologic effects resulting from x irradiation are discussed. The transient phenomenon of external pigmentation development due to ionizing radiation was noted. The swim bladder, a hydrostatic organ, was frequently observed to be in a deflated condition after exposure to doses greatermore » than 500 r, resulting in loss of buoyancy. The increase in the susceptibility of irradiated animals to an experimentally induced bacterial infection, Aeromonas salmonicida, and to a naturally acquired ectoparasitic trematode, Gyrodactylus spp., was also observed. (auth)« less

Exposure Factors Handbook (1996, External Review Draft)

EPA Science Inventory

This handbook provided a summary of the available statistical data on various factors used in assessing human exposure.

Volume I, General Factors, includes an introduction and discussion of uncertainty and provides data for drinking water consumption, soil ingestion, inha...

Similar causes of various reproductive disorders in early life.

PubMed

Svechnikov, Konstantin; Stukenborg, Jan-Bernd; Savchuck, Iuliia; Söder, Olle

2014-01-01

During the past few decades, scientific evidence has been accumulated concerning the possible adverse effects of the exposure to environmental chemicals on the well-being of wildlife and human populations. One large and growing group of such compounds of anthropogenic or natural origin is referred to as endocrine-disrupting chemicals (EDCs), due to their deleterious action on the endocrine system. This concern was first focused on the control of reproductive function particularly in males, but has later been expanded to include all possible endocrine functions. The present review describes the underlying physiology behind the cascade of developmental events that occur during sexual differentiation of males and the specific role of androgen in the masculinization process and proper organogenesis of the external male genitalia. The impact of the genetic background, environmental exposures and lifestyle factors in the etiology of hypospadias, cryptorchidism and testicular cancer are reviewed and the possible role of EDCs in the development of these reproductive disorders is discussed critically. Finally, the possible direct and programming effects of exposures in utero to widely use therapeutic compounds, environmental estrogens and other chemicals on the incidence of reproductive abnormalities and poor semen quality in humans are also highlighted.

Biological monitoring of iodine, a water disinfectant for long-term space missions

NASA Technical Reports Server (NTRS)

Zareba, G.; Cernichiari, E.; Goldsmith, L. A.; Clarkson, T. W.

1995-01-01

In order to establish guidelines for exposure of astronauts to iodine, used as a water disinfectant in space, we studied the usefulness of hair, saliva, and urine for biological monitoring in humans and in the human hair/nude mouse model. The monitoring of iodine in patients that received 150 mCi of Na131I (carrier-free) showed similar patterns of elimination for blood, saliva, and urine. The mean correlation coefficient (r) between iodine elimination for blood/saliva was 0.99, for blood/urine, 0.95, and for saliva/urine, 0.97. The absolute value of iodine concentrations in urine revealed marked variability, which was corrected by adjusting for creatinine levels. The autoradiographic studies of human hair demonstrated that iodine is rapidly incorporated into external layers of the hair root and can be removed easily during washing. These data were confirmed after iodine exposure using the human hair/nude mouse model. Hair does not provide satisfactory information about exposure due to unstable incorporation of iodine. The most useful medium for biological monitoring of astronauts exposed to high doses of iodine in drinking water is urine, when adjusted for creatinine, and saliva, if quantitative evaluation of flow rate is provided.

Early exposure to geriatric nursing through an externship program.

PubMed

Souder, Elaine; Beverly, Claudia J; Kitch, Stephanie; Lubin, Sandie A

2012-01-01

The Summer Geriatric Extern Program was developed in 2004 to provide nursing students between the junior and senior year an opportunity to learn more about careers in geriatric nursing.This full-time, eight-week commitment provides students with a stipend and a faculty mentor in their area of interest. Of the 24 externs since the inception of the program, seven have enrolled in graduate programs. The findings suggest that the summer geriatric externship program is effective in developing interest in a geriatric nursing career and providing exposure to nursing research and other aspects of the faculty role.

Exposure and inhalation risk assessment in an aluminium cast-house.

PubMed

Godderis, L; Vanderheyden, W; Van Geel, J; Moens, G; Masschelein, R; Veulemans, H

2005-12-01

To date the exposure, absorption and respiratory health effects of cast-house workers have not been described since most studies performed in the aluminium industry are focused on exposure and health effects of potroom personnel. In the present study, we assessed the external exposure and the absorbed dose of metals in personnel from the aluminium cast house. This was combined with an evaluation of respiratory complaints and the lung function of the personnel. 30 workers from an aluminium casting plant participated and 17 individuals of the packaging and distribution departments were selected as controls. The exposure was assessed by the quantification of total inhalable fume with metal fraction and by the determination of urinary aluminium, chromium, beryllium, manganese and lead concentration. Carbon monoxide (CO), carbon dioxide (CO2), aldehydes and polyaromatic hydrocarbons and man-made mineral fibres concentration were assessed as well. In order to evaluate their respiratory status each participant filled out a questionnaire and their lung function was tested by forced spirometry. Total inhalable fume exposure was maximum 4.37 mg m(-3). Exposure to the combustion gases, man-made mineral fibres and metal fume was well below the exposure limits. Beryllium could not be detected in the urine. The values of aluminium, manganese and lead in the urine were all under the respective reference value. One individual had a urinary chromium excretion above the ACGIH defined biological exposure index (BEI) of 30 microg g(-1) creatinine. There was no significant difference in any of the categories of the respiratory questionnaire and in the results of the spirometry between cast house personnel and referents (Chi-square, all p > 0.05). Exposure in cast houses seem to be acceptable under these conditions. However, peak exposure to fumes cannot be excluded and the potential risk of chromium and beryllium exposure due to the recycling of aluminium requires further attention.

Metabolically-Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates (External Review Draft)

EPA Science Inventory

EPA has released a draft report entitled, Metabolically-Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates, for independent external peer review and public comment. NCEA published the Exposure Factors Handbook in 1997. This comprehens...

10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

Code of Federal Regulations, 2014 CFR

2014-01-01

... internal occupational dose. 20.1502 Section 20.1502 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Surveys and Monitoring § 20.1502 Conditions requiring individual monitoring of external and internal occupational dose. Each licensee shall monitor exposures to radiation and radioactive...

10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

Code of Federal Regulations, 2012 CFR

2012-01-01

... internal occupational dose. 20.1502 Section 20.1502 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Surveys and Monitoring § 20.1502 Conditions requiring individual monitoring of external and internal occupational dose. Each licensee shall monitor exposures to radiation and radioactive...

10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

Code of Federal Regulations, 2011 CFR

2011-01-01

... internal occupational dose. 20.1502 Section 20.1502 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Surveys and Monitoring § 20.1502 Conditions requiring individual monitoring of external and internal occupational dose. Each licensee shall monitor exposures to radiation and radioactive...

10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

Code of Federal Regulations, 2013 CFR

2013-01-01

... internal occupational dose. 20.1502 Section 20.1502 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Surveys and Monitoring § 20.1502 Conditions requiring individual monitoring of external and internal occupational dose. Each licensee shall monitor exposures to radiation and radioactive...

10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

Code of Federal Regulations, 2010 CFR

2010-01-01

... internal occupational dose. 20.1502 Section 20.1502 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Surveys and Monitoring § 20.1502 Conditions requiring individual monitoring of external and internal occupational dose. Each licensee shall monitor exposures to radiation and radioactive...

[Principles of antisepsis, disinfection and sterilization].

PubMed

Hernández-Navarrete, María-Jesús; Celorrio-Pascual, José-Miguel; Lapresta Moros, Carlos; Solano Bernad, Victor-Manuel

2014-12-01

This article aims to provide a brief review of the main concepts on which the prevention and control of infection are based. Antisepsis comprises a set of techniques aimed at the total sterilization, or at most, disinfection, removing germs that contaminate an environment. Both procedures must be preceded by an environmental cleanup in the location in which they intend to be applied. The disinfection is carried out using biocides or germicides. Antimicrobial chemicals, that have mechanisms of action and resistances very similar to antibiotics, are generating concern due to the possibility of crossing genetic information that aggravates the problem of bacterial resistance. Most biocides can act as antiseptics, and applied to skin tissue, or disinfectants on inanimate materials. The spectrum of action of germicides depends on the product itself and external controllable factors: temperature, concentration, exposure time, etc. Sterilization techniques are primarily physical, by exposing the material to steam, or sterilizing gas, using autoclaves. Major advances are the use of low temperatures with shorter exposure times, in parallel with technological advances in instrumentation in order to avoid high temperatures and high use rotations due to workload. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Internalizing and externalizing symptoms among Palestinian adolescents from Israel as consequences of their exposure to community violence: Are they moderated by their self-efficacy and collective efficacy?

PubMed

Darawshy, Neveen Ali-Saleh; Haj-Yahia, Muhammad M

2018-05-01

This article presents the findings of a study that examined the rates and the consequences of exposure to community violence (ECV) as reflected in witnessing and experiencing such violence, among Palestinian adolescents from Israel. In particular, it examined the extent to which these adolescents exhibit high levels of internalizing and externalizing symptoms as consequences of such exposure, and the extent to which self-efficacy and collective efficacy moderate these consequences. A systematic random sample of 760 Palestinian adolescents in Israel (320 boys, and 440 girls) filled out a self-administered questionnaire. The results show that most of the adolescents had witnessed community violence during the last year and during lifetime, and more than one third had directly experienced such violence during their lifetime compared with 19.6% during the last year. Boys were exposed to community violence more often than girls. Moreover, participants' ECV predicted high levels of externalizing and internalizing symptoms. Hierarchical regression analysis revealed that collective efficacy moderated the correlation between experiencing community violence and internalizing symptoms, whereas self-efficacy moderated the correlation between witnessing community violence and externalizing symptoms. There is a need for providing support for youth from close adults as well as from formal and informal resources in the community before and after their ECV. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantitative comparisons of cancer induction in humans by internally deposited radionuclides and external radiation.

PubMed

Harrison, J D; Muirhead, C R

2003-01-01

To compare quantitative estimates of lifetime cancer risk in humans for exposures to internally deposited radionuclides and external radiation. To assess the possibility that risks from radionuclide exposures may be underestimated. Risk estimates following internal exposures can be made for a small number of alpha-particle-emitting nuclides. (1) Lung cancer in underground miners exposed by inhalation to radon-222 gas and its short-lived progeny. Studies of residential (222)Rn exposure are generally consistent with predictions from the miner studies. (2) Liver cancer and leukaemia in patients given intravascular injections of Thorotrast, a thorium-232 oxide preparation that concentrates in liver, spleen and bone marrow. (3) Bone cancer in patients given injections of radium-224, and in workers exposed occupationally to (226)Ra and (228)Ra, mainly by ingestion. (4) Lung cancer in Mayak workers exposed to plutonium-239, mainly by inhalation. Liver and bone cancers were also seen, but the dosimetry is not yet sufficiently good enough to provide quantitative estimates of risks. Comparisons can be made between risk estimates for radiation-induced cancer derived for radionuclide exposure and those derived for the A-bomb survivors, exposed mainly to low-LET (linear energy transfer) external radiation. Data from animal studies, using dogs and rodents, allow comparisons of cancer induction by a range of alpha- and beta-/gamma-emitting radionuclides. They provide information on relative biological effectiveness (RBE), dose-response relationships, dose-rate effects and the location of target cells for different malignancies. For lung and liver cancer, the estimated values of risk per Sv for internal exposure, assuming an RBE for alpha-particles of 20, are reasonably consistent with estimates for external exposure to low-LET radiation. This also applies to bone cancer when risk is calculated on the basis of average bone dose, but consideration of dose to target cells on bone surfaces suggests a low RBE for alpha-particles. Similarly, for leukaemia, the comparison of risks from alpha-irradiation ((232)Th and progeny) and external radiation suggest a low alpha RBE; this conclusion is supported by animal data. Risk estimates for internal exposure are dependent on the assumptions made in calculating dose. Account is taken of the distribution of radionuclides within tissues and the distribution of target cells for cancer induction. For the lungs and liver, the available human and animal data provide support for current assumptions. However, for bone cancer and leukaemia, it may be that changes are required. Bone cancer risk may be best assessed by calculating dose to a 50 micro m layer of marrow adjacent to endosteal (inner) bone surfaces rather than to a single 10 micro m cell layer as currently assumed. Target cells for leukaemia may be concentrated towards the centre of marrow cavities so that the risk of leukaemia from bone-seeking radionuclides, particularly alpha emitters, may be overestimated by the current assumption of uniform distribution of target cells throughout red bone marrow. The lifetime risk estimates considered here for exposure to internally deposited radionuclides and to external radiation are subject to uncertainties, arising from the dosimetric assumptions made, from the quality of cancer incidence and mortality data and from aspects of risk modelling; including variations in baseline rates between populations for some cancer types. Bearing in mind such uncertainties, comparisons of risk estimates for internal emitters and external radiation show good agreement for lung and liver cancers. For leukaemia, the available data suggest that the assumption of an alpha-particle RBE of 20 can result in overestimates of risk. For bone cancer, it also appears that current assumptions will overestimate risks from alpha-particle-emitting nuclides, particularly at low doses.

Roles of children and their parents in the reduction of radiation risk after the 2011 Fukushima Daiichi Nuclear Power Plant accident.

PubMed

Fujimura, Maya Sophia; Komasa, Yukako; Kimura, Shinzo; Shibanuma, Akira; Kitamura, Akiko; Jimba, Masamine

2017-01-01

On March 11, 2011, Japan experienced its largest recorded earthquake with a magnitude of 9.0. The resulting tsunami caused massive damage to the Fukushima Daiichi Nuclear Power Plant reactors, and the surrounding environment was contaminated with radioactive materials. During this period, some residents were exposed to high levels of radiation (up to 5 millisieverts [mSv]), but since then, many residents have been exposed to low levels of radiation (<1 mSv). This study was conducted to assess the effects of lifestyle and attitude factors on external radiation exposure among Fukushima residents. This community-based, cross-sectional study was conducted in Nihonmatsu City of the Fukushima Prefecture from May to July 2014. The population survey targeted 6,884 children between the ages of 0-15 years, and a personal radiation badge and questionnaire were administered to each of the residences. Multiple linear regression analysis was used to assess the impact of lifestyle and attitude factors on external radiation dose. The study participants (population size [n] = 4,571) had an additional mean radiation dose of 0.65 mSv/year, which is small as compared to the mean radiation dose 6 months after the disaster (1.5 mSv/year), in 2012 (1.5 mSv/year), and in 2013 (1.0 mSv/year). External radiation doses statistically varied by socio-demographic and lifestyle factors. Participants living in wooden residences (p-value<0.001) and within 100 meters of a forest (p = 0.001) had higher radiation exposure. Conversely, participants with a cautious attitude towards radiation had lower radiation exposure (beta [b] = -0.124, p = 0.003). Having a cautious attitude towards radiation and being aware of exposure risks proved to be significant in the reduction of external radiation dose. Therefore, in the event of future radiation disasters, attitudes towards and awareness of radiation should be considered in the reduction of exposure risk and implementation of radiation protection.

Unified method to integrate and blend several, potentially related, sources of information for genetic evaluation.

PubMed

Vandenplas, Jérémie; Colinet, Frederic G; Gengler, Nicolas

2014-09-30

A condition to predict unbiased estimated breeding values by best linear unbiased prediction is to use simultaneously all available data. However, this condition is not often fully met. For example, in dairy cattle, internal (i.e. local) populations lead to evaluations based only on internal records while widely used foreign sires have been selected using internally unavailable external records. In such cases, internal genetic evaluations may be less accurate and biased. Because external records are unavailable, methods were developed to combine external information that summarizes these records, i.e. external estimated breeding values and associated reliabilities, with internal records to improve accuracy of internal genetic evaluations. Two issues of these methods concern double-counting of contributions due to relationships and due to records. These issues could be worse if external information came from several evaluations, at least partially based on the same records, and combined into a single internal evaluation. Based on a Bayesian approach, the aim of this research was to develop a unified method to integrate and blend simultaneously several sources of information into an internal genetic evaluation by avoiding double-counting of contributions due to relationships and due to records. This research resulted in equations that integrate and blend simultaneously several sources of information and avoid double-counting of contributions due to relationships and due to records. The performance of the developed equations was evaluated using simulated and real datasets. The results showed that the developed equations integrated and blended several sources of information well into a genetic evaluation. The developed equations also avoided double-counting of contributions due to relationships and due to records. Furthermore, because all available external sources of information were correctly propagated, relatives of external animals benefited from the integrated information and, therefore, more reliable estimated breeding values were obtained. The proposed unified method integrated and blended several sources of information well into a genetic evaluation by avoiding double-counting of contributions due to relationships and due to records. The unified method can also be extended to other types of situations such as single-step genomic or multi-trait evaluations, combining information across different traits.

Strengthening the Case: Prenatal Alcohol Exposure is Associated with Increased Risk for Conduct Disorder

PubMed Central

Disney, Elizabeth R.; Iacono, William; McGue, Matthew; Tully, Erin; Legrand, Lisa

2008-01-01

Objective The purpose of this study was to examine the relationship between alcohol exposure in pregnancy and offspring conduct disorder (CD) symptoms in adolescence, and to examine how much this increasingly well-known association may be mediated by maternal and paternal externalizing diagnoses, including lifetime maternal and paternal alcohol and drug abuse/dependence diagnoses as well as antisocial disorders. Few other studies have examined the contribution of these diagnoses across both parents. Method A population sample of 1252 adolescents (53.8% female; drawn from the Minnesota Twin Family Study) as well as both their parents completed structured diagnostic interviews to generate lifetime psychiatric diagnoses; mothers were also retrospectively interviewed about alcohol and nicotine use during pregnancy. Linear regression models were used to test the effects of prenatal alcohol exposure on adolescents' CD symptoms. Results Prenatal exposure to alcohol was associated with higher levels of CD symptoms in offspring, even after statistically controlling for the effects of parental externalizing disorders (i.e., illicit substance use disorders, alcohol dependence, and antisocial/behavioral disorders), prenatal nicotine exposure, monozygosity, gestational age, and birth weight. Conclusions Prenatal alcohol exposure contributes to increased risk for CD in offspring. PMID:19047223

Interaction between pancreatic β cell and electromagnetic fields: A systematic study toward finding the natural frequency spectrum of β cell system.

PubMed

Farashi, Sajjad

2017-01-01

Interaction between biological systems and environmental electric or magnetic fields has gained attention during the past few decades. Although there are a lot of studies that have been conducted for investigating such interaction, the reported results are considerably inconsistent. Besides the complexity of biological systems, the important reason for such inconsistent results may arise due to different excitation protocols that have been applied in different experiments. In order to investigate carefully the way that external electric or magnetic fields interact with a biological system, the parameters of excitation, such as intensity or frequency, should be selected purposefully due to the influence of these parameters on the system response. In this study, pancreatic β cell, the main player of blood glucose regulating system, is considered and the study is focused on finding the natural frequency spectrum of the system using modeling approach. Natural frequencies of a system are important characteristics of the system when external excitation is applied. The result of this study can help researchers to select proper frequency parameter for electrical excitation of β cell system. The results show that there are two distinct frequency ranges for natural frequency of β cell system, which consist of extremely low (or near zero) and 100-750 kHz frequency ranges. There are experimental works on β cell exposure to electromagnetic fields that support such finding.

Mortality (1968-2008) in a French cohort of uranium enrichment workers potentially exposed to rapidly soluble uranium compounds.

PubMed

Zhivin, Sergey; Guseva Canu, Irina; Samson, Eric; Laurent, Olivier; Grellier, James; Collomb, Philippe; Zablotska, Lydia B; Laurier, Dominique

2016-03-01

Until recently, enrichment of uranium for civil and military purposes in France was carried out by gaseous diffusion using rapidly soluble uranium compounds. We analysed the relationship between exposure to soluble uranium compounds and exposure to external γ-radiation and mortality in a cohort of 4688 French uranium enrichment workers who were employed between 1964 and 2006. Data on individual annual exposure to radiological and non-radiological hazards were collected for workers of the AREVA NC, CEA and Eurodif uranium enrichment plants from job-exposure matrixes and external dosimetry records, differentiating between natural, enriched and depleted uranium. Cause-specific mortality was compared with the French general population via standardised mortality ratios (SMR), and was analysed via Poisson regression using log-linear and linear excess relative risk models. Over the period of follow-up, 131 161 person-years at risk were accrued and 21% of the subjects had died. A strong healthy worker effect was observed: all causes SMR=0.69, 95% CI 0.65 to 0.74. SMR for pleural cancer was significantly increased (2.3, 95% CI 1.06 to 4.4), but was only based on nine cases. Internal uranium and external γ-radiation exposures were not significantly associated with any cause of mortality. This is the first study of French uranium enrichment workers. Although limited in statistical power, further follow-up of this cohort, estimation of internal uranium doses and pooling with similar cohorts should elucidate potential risks associated with exposure to soluble uranium compounds. 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/

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure, antioxidant levels and behavioral development of children ages 6-9.

PubMed

Genkinger, Jeanine M; Stigter, Laura; Jedrychowski, Wieslaw; Huang, Tzu-Jung; Wang, Shuang; Roen, Emily L; Majewska, Renata; Kieltyka, Agnieszka; Mroz, Elzbieta; Perera, Frederica P

2015-07-01

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure has been shown to increase DNA adduct levels and to affect neurodevelopment. Micronutrients may modify the adverse effect of PAH on neurodevelopment. Thus, we examined if micronutrient concentrations modified the association between PAH exposure and neurodevelopmental outcomes. 151 children from a birth cohort who had micronutrient concentrations measured in cord blood and completed the Child Behavioral Checklist (CBCL), between the ages of 6 and 9 years, were evaluated. Prenatal airborne PAH exposure was measured by personal air monitoring. The betas and 95% CI for the associations of antioxidant concentrations and PAH exposure with each of the outcomes of CBCL raw score and dichotomized standardized T-score (based on clinical cutpoints) were estimated, respectively, by multivariable poisson and logistic models. Children below the median for alpha-tocopherol and gamma-tocopherol concentrations, compared to those above, were more likely to have thought problems, aggressive behavior and externalizing problems (p<0.05). Lower carotenoid concentration was associated with more thought problems (MVβ=0.60, p<0.001) and externalizing problems (MVβ=0.13, p<0.05) for the same contrast. No statistically significant associations were observed between retinol concentrations and neurodevelopmental symptoms. Overall, no consistent patterns were observed when we examined the interaction between antioxidants (e.g., alpha-tocopherol) and PAH in relation to CBCL symptoms (e.g., internalizing and externalizing problems, p<0.05). Lower alpha-tocopherol, gamma-tocopherol and carotenoid levels may adversely affect healthy neurodevelopment, even after accounting for PAH exposure. Future research to confirm these findings are warranted given the importance of identifying modifiable factors for reducing harmful PAH effects. Copyright © 2015 Elsevier Inc. All rights reserved.

Modeling of an industrial environment: external dose calculations based on Monte Carlo simulations of photon transport.

PubMed

Kis, Zoltán; Eged, Katalin; Voigt, Gabriele; Meckbach, Reinhard; Müller, Heinz

2004-02-01

External gamma exposures from radionuclides deposited on surfaces usually result in the major contribution to the total dose to the public living in urban-industrial environments. The aim of the paper is to give an example for a calculation of the collective and averted collective dose due to the contamination and decontamination of deposition surfaces in a complex environment based on the results of Monte Carlo simulations. The shielding effects of the structures in complex and realistic industrial environments (where productive and/or commercial activity is carried out) were computed by the use of Monte Carlo method. Several types of deposition areas (walls, roofs, windows, streets, lawn) were considered. Moreover, this paper gives a summary about the time dependence of the source strengths relative to a reference surface and a short overview about the mechanical and chemical intervention techniques which can be applied in this area. An exposure scenario was designed based on a survey of average German and Hungarian supermarkets. In the first part of the paper the air kermas per photon per unit area due to each specific deposition area contaminated by 137Cs were determined at several arbitrary locations in the whole environment relative to a reference value of 8.39 x 10(-4) pGy per gamma m(-2). The calculations provide the possibility to assess the whole contribution of a specific deposition area to the collective dose, separately. According to the current results, the roof and the paved area contribute the most part (approximately 92%) to the total dose in the first year taking into account the relative contamination of the deposition areas. When integrating over 10 or 50 y, these two surfaces remain the most important contributors as well but the ratio will increasingly be shifted in favor of the roof. The decontamination of the roof and the paved area results in about 80-90% of the total averted collective dose in each calculated time period (1, 10, 50 y).

Standing adult human phantoms based on 10th, 50th and 90th mass and height percentiles of male and female Caucasian populations

NASA Astrophysics Data System (ADS)

Cassola, V. F.; Milian, F. M.; Kramer, R.; de Oliveira Lira, C. A. B.; Khoury, H. J.

2011-07-01

Computational anthropomorphic human phantoms are useful tools developed for the calculation of absorbed or equivalent dose to radiosensitive organs and tissues of the human body. The problem is, however, that, strictly speaking, the results can be applied only to a person who has the same anatomy as the phantom, while for a person with different body mass and/or standing height the data could be wrong. In order to improve this situation for many areas in radiological protection, this study developed 18 anthropometric standing adult human phantoms, nine models per gender, as a function of the 10th, 50th and 90th mass and height percentiles of Caucasian populations. The anthropometric target parameters for body mass, standing height and other body measures were extracted from PeopleSize, a well-known software package used in the area of ergonomics. The phantoms were developed based on the assumption of a constant body-mass index for a given mass percentile and for different heights. For a given height, increase or decrease of body mass was considered to reflect mainly the change of subcutaneous adipose tissue mass, i.e. that organ masses were not changed. Organ mass scaling as a function of height was based on information extracted from autopsy data. The methods used here were compared with those used in other studies, anatomically as well as dosimetrically. For external exposure, the results show that equivalent dose decreases with increasing body mass for organs and tissues located below the subcutaneous adipose tissue layer, such as liver, colon, stomach, etc, while for organs located at the surface, such as breasts, testes and skin, the equivalent dose increases or remains constant with increasing body mass due to weak attenuation and more scatter radiation caused by the increasing adipose tissue mass. Changes of standing height have little influence on the equivalent dose to organs and tissues from external exposure. Specific absorbed fractions (SAFs) have also been calculated with the 18 anthropometric phantoms. The results show that SAFs decrease with increasing height and increase with increasing body mass. The calculated data suggest that changes of the body mass may have a significant effect on equivalent doses, primarily for external exposure to organs and tissue located below the adipose tissue layer, while for superficial organs, for changes of height and for internal exposures the effects on equivalent dose are small to moderate.

Plurality of Birth and Infant Mortality Due to External Causes in the United States, 2000-2010.

PubMed

Ahrens, Katherine A; Thoma, Marie E; Rossen, Lauren M; Warner, Margaret; Simon, Alan E

2017-03-01

Risk of death during the first year of life due to external causes, such as unintentional injury and homicide, may be higher among twins and higher-order multiples than among singletons in the United States. We used national birth cohort linked birth-infant death data (2000-2010) to evaluate the risk of infant mortality due to external causes in multiples versus singletons in the United States. Risk of death from external causes during the study period was 3.6 per 10,000 live births in singletons and 5.1 per 10,000 live births in multiples. Using log-binomial regression, the corresponding unadjusted risk ratio was 1.40 (95% confidence interval (CI): 1.30, 1.50). After adjustment for maternal age, marital status, race/ethnicity, and education, the risk ratio was 1.68 (95% CI: 1.56, 1.81). Infant deaths due to external causes were most likely to occur between 2 and 7 months of age. Applying inverse probability weighting and assuming a hypothetical intervention where no infants were low birth weight, the adjusted controlled direct effect of plurality on infant mortality due to external causes was 1.64 (95% CI: 1.39, 1.97). Twins and higher-order multiples were at greater risk of infant mortality due to external causes, particularly between 2 and 7 months of age, and this risk appeared to be mediated largely by factors other than low-birth-weight status. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

[Analysis of the trend and impact of mortality due to external causes: Mexico, 2000-2013].

PubMed

Dávila Cervantes, Claudio Alberto; Pardo Montaño, Ana Melisa

2016-01-01

The objective of this study was to analyze mortality due to the main external causes of death (traffic accidents, other accidents, homicides and suicides) in Mexico, calculating the years of life lost between 0 and 100 years of age and their contribution to the change in life expectancy between 2000 and 2013, at the national level, by sex and age group. Data came from mortality vital statistics of the Instituto Nacional de Estadística y Geografía (INEGI) [National Institute of Statistics and Geography]. The biggest impact in mortality due to external causes occurred in adolescent and adult males 15-49 years of age; mortality due to these causes remained constant in males and slightly decreased in females. Mortality due to traffic accidents and other accidents decreased, with a positive contribution to life expectancy, but this effect was canceled out by the increase in mortality due to homicides and suicides. Mortality due to external causes can be avoided through interventions, programs and prevention strategies as well as timely treatment. It is necessary to develop multidisciplinary studies on the dynamics of the factors associated with mortality due to these causes.

Monitoring of fetal radiation exposure during pregnancy.

PubMed

Chandra, Venita; Dorsey, Chelsea; Reed, Amy B; Shaw, Palma; Banghart, Dawn; Zhou, Wei

2013-09-01

One unique concern of vascular surgeons and trainees is radiation exposure associated with increased endovascular practice. The safety of childbearing is a particular worry for current and future women in vascular surgery. Little is known regarding actual fetal radiation exposure. This multi-institutional study aimed to evaluate the radiation dosages recorded on fetal dosimeter badges and compare them to external badges worn by the same cohort of women. All women who declared pregnancy with potential radiation exposure were required to wear two radiation monitors at each institution, one outside and the other inside the lead apron. Maternal (external) and fetal monitor dosimeter readings were analyzed. Maternal radiation exposures prior to, during, and postpregnancy were also assessed to determine any associated behavior modification. Eighty-one women declared pregnancy from 2008 to 2011 and 32 had regular radiation exposure during pregnancy. Maternal whole-body exposures ranged from 21-731 mrem. The average fetal dosimeter recordings for the cohort rounded to zero. Only two women had positive fetal dosimeter recordings; one had a single recording of 3 mrem and the other had a single recording of 7 mrem. There was no significant difference between maternal exposures prior to, during, and postpregnancy. Lack of knowledge of fetal radiation exposure has concerned many vascular surgeons, prompting them to wear double lead aprons during pregnancy, and perhaps prevented numerous other women from entering the field. Our study showed negligible radiation exposure on fetal monitoring suggesting that with the appropriate safety precautions, these concerns may be unwarranted. Published by Mosby, Inc.

Cardio-autonomic control and wellbeing due to oscillating color light exposure.

PubMed

Grote, Vincent; Kelz, Christina; Goswami, Nandu; Stossier, Harald; Tafeit, Erwin; Moser, Maximilian

2013-04-10

We investigated the cardio-autonomic and psychological effects of colored light cycling with the wavelength of ultradian rhythms. In two consecutive experiments, an explorative, longitudinal test followed by a randomized crossover design, 20 healthy subjects each were exposed to oscillating red, green and blue light. Heart rate, heart rate variability (HRV) and subjective wellbeing were measured. Significant effects of the oscillating color light exposure were observed for heart rate and cardio-autonomic control rhythms, derived from HRV (p≤.001). These effects on HRV were replicated in the second experiment in comparison to a similar white light exposure protocol (p≤.05). Vigilance showed improvement over the two weeks (p≤.001) in the longitudinal study. External color light cycling at the wavelength of blood pressure oscillations appears to amplify the endogenous autonomic oscillations. This leads to an optimization of cardio-autonomic control; an effect that was reflected shortly after the onset of the light exposure sessions by the increase of heart rate variability. From the results, we conclude that it takes repeated light exposure session to foster the positive effects on the psychological aspects, as we observed an increase of subjectively perceived mood only in the longitudinal study, not for the crossover design study. The results of our study imply some possible health effects of a color light exposure that is adjusted to 10 s and 1 min oscillations of humans' ultradian rhythms. These novel results show possible applications of oscillating visual inputs to the activation of processes connected to physiological regulation. Copyright © 2013 Elsevier Inc. All rights reserved.

Psychological, neuropsychological, and electrocortical effects of mixed mold exposure.

PubMed

Crago, B Robert; Gray, Michael R; Nelson, Lonnie A; Davis, Marilyn; Arnold, Linda; Thrasher, Jack D

2003-08-01

The authors assessed the psychological, neuropsychological, and electrocortical effects of human exposure to mixed colonies of toxigenic molds. Patients (N = 182) with confirmed mold-exposure history completed clinical interviews, a symptom checklist (SCL-90-R), limited neuropsychological testing, quantitative electroencephalogram (QEEG) with neurometric analysis, and measures of mold exposure. Patients reported high levels of physical, cognitive, and emotional symptoms. Ratings on the SCL-90-R were "moderate" to "severe," with a factor reflecting situational depression accounting for most of the variance. Most of the patients were found to suffer from acute stress, adjustment disorder, or post-traumatic stress. Differential diagnosis confirmed an etiology of a combination of external stressors, along with organic metabolically based dysregulation of emotions and decreased cognitive functioning as a result of toxic or metabolic encephalopathy. Measures of toxic mold exposure predicted QEEG measures and neuropsychological test performance. QEEG results included narrowed frequency bands and increased power in the alpha and theta bands in the frontal areas of the cortex. These findings indicated a hypoactivation of the frontal cortex, possibly due to brainstem involvement and insufficient excitatory input from the reticular activating system. Neuropsychological testing revealed impairments similar to mild traumatic brain injury. In comparison with premorbid estimates of intelligence, findings of impaired functioning on multiple cognitive tasks predominated. A dose-response relationship between measures of mold exposure and abnormal neuropsychological test results and QEEG measures suggested that toxic mold causes significant problems in exposed individuals. Study limitations included lack of a comparison group, patient selection bias, and incomplete data sets that did not allow for comparisons among variables.

Application of in Vitro Biotransformation Data and Pharmacokinetic Modeling to Risk Assessment

EPA Science Inventory

The adverse biological effects of toxic substances are dependent upon the exposure concentration and the duration of exposure. Pharmacokinetic models can quantitatively relate the external concentration of a toxicant in the environment to the internal dose of the toxicant in the ...

Child-Specific Exposure Factors Handbook (2006, External Review Draft)

EPA Science Inventory

Children are often more heavily exposed to environmental toxicants than adults. They consume more...

School-External Factors in Finnish Content and Language Integrated Learning (CLIL) Programs

ERIC Educational Resources Information Center

Aro, Sophie; Mikkilä-Erdmann, Mirjamaija

2015-01-01

This study investigated the relationship between the English language competence of Finnish bilingual pupils and school-external factors such as parental expectations, home involvement, and exposure to English outside the classroom. Data on the pupils' language competence was collected from n?=?122 6th graders in bilingual education, and compared…

Temperament Moderates Associations between Exposure to Stress and Children's Externalizing Problems

ERIC Educational Resources Information Center

Schermerhorn, Alice C.; Bates, John E.; Goodnight, Jackson A.; Lansford, Jennifer E.; Dodge, Kenneth A.; Pettit, Gregory S.

2013-01-01

The interaction between a temperament profile (four groups determined by high vs. low resistance to control [unmanageability] and unadaptability [novelty distress]) and family stress in predicting externalizing problems at school in children followed from kindergarten through eighth grade (ages 5-13) was investigated. The sample consisted of 556…

Exposure to Family Violence and Internalizing and Externalizing Problems Among Spanish Adolescents.

PubMed

Izaguirre, Ainhoa; Calvete, Esther

2018-04-01

Exposure to intimate partner violence (IPV) and child maltreatment may have devastating consequences on children's development. The aim of this research was to examine the predictive associations between exposure to violence at home (witnessing violence against the mother and/or direct victimization by the parents) and adolescent internalizing and externalizing problems. A total of 613 Spanish adolescents (13-18 years) took part in this study. Results indicate that psychological victimization by the parents predicted an increase in anxious/depressive symptoms, aggressive and rule-breaking behavior, and substance abuse at Time 2. In addition, rule-breaking behavior predicted an increase in adolescents' substance abuse at Time 2. Concerning gender, psychological victimization predicted an increase in anxiety/depression, aggressive behavior, rule-breaking behavior, and substance abuse in boys; whereas in girls, psychological victimization only predicted an increase in anxiety/depression.

A clinical assessment of the anterior eye in arc welders.

PubMed

Doughty, Michael J; Oblak, Emil

2005-11-01

Corneal irradiation with high doses of ultraviolet-B (UVB) has been shown to damage the corneal endothelium in animals. Human occupational exposure to ultraviolet radiation (UVR) in welding is considered a risk for endothelial damage but the evidence for such an effect is limited. External eye photographs and non-contact specular micrographs (Topcon SP2000-P) were obtained from 102 white males aged between 32 and 62 years, 51 being arc welders (with 24 +/- 7 years experience) and 51 office workers. Most welders reported repeated occupational exposure to UVR (that is, welder's 'flashes'). Welders reported a higher level of ocular symptoms and a higher prevalence of pingueculae (47 versus 12 per cent), but only one case with pterygium. The average endothelial cell areas were the same in welders and office workers (398 +/- 55 microm(2) versus 400 +/- 56 microm(2); p = 0.868) as were the endothelial cell density (ECD) values (2,555 +/- 342 cells/mm(2) versus 2,541 +/- 308 cells/mm(2); p = 0.825). ECD decreased with years of welding experience (p < 0.01) but not faster than the decrease in ECD due to age. Repeated occupational ultraviolet radiation exposure through welding is not associated with any obvious differences in the corneal endothelium. No differences were observed in either ECD or cell polymegethism. Despite the periodic welding flashes, the exposure levels are below those needed to cause damage to the corneal endothelium.

A national survey of natural radionuclides in soils and terrestrial radiation exposure in Iran.

PubMed

Kardan, M R; Fathabdi, N; Attarilar, A; Esmaeili-Gheshlaghi, M T; Karimi, M; Najafi, A; Hosseini, S S

2017-11-01

In the past, some efforts have been made for measuring natural radioactivity and evaluating public exposure to natural radiation in certain areas of Iran especially in well-known High Level Natural Radiation Areas (HLNRA) in Ramsar and Mahallat. However, the information on radionuclide concentrations, and, consequently, terrestrial radiation exposure for many other areas are not available. There was therefore a need for a systematic and nation-wide survey. For this purpose, 979 soil samples from 31 provinces were collected. The activity concentrations of 40 K, 226 Ra and 232 Th were measured by HPGe detector. The average activity concentrations for Iran were found to be 457.7 Bq/kg for 40 K, 24.3 Bq/kg for 226 Ra and 25.8 Bq/kg for 232 Th. Results were compared with previous regional or provincial surveys. The population-weighted average outdoor and indoor annual effective dose due to external exposure to terrestrial sources of radiation are 0.06 mSv and 0.33 mSv, respectively. It was shown that there is a significant correlation between the activity concentrations of 232 Th and 40 K in soil. In addition, the results of chi square tests show normal and lognormal distributions cannot be considered for the frequency distributions of activity concentration of 232 Th and 226 Ra while 40 K has a normal distribution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protective factors can mitigate behavior problems after prenatal cocaine and other drug exposures.

PubMed

Bada, Henrietta S; Bann, Carla M; Whitaker, Toni M; Bauer, Charles R; Shankaran, Seetha; Lagasse, Linda; Lester, Barry M; Hammond, Jane; Higgins, Rosemary

2012-12-01

We determined the role of risk and protective factors on the trajectories of behavior problems associated with high prenatal cocaine exposure (PCE)/polydrug exposure. The Maternal Lifestyle Study enrolled 1388 children with or without PCE, assessed through age 15 years. Because most women using cocaine during pregnancy also used other substances, we analyzed for the effects of 4 categories of prenatal drug exposure: high PCE/other drugs (OD), some PCE/OD, OD/no PCE, and no PCE/no OD. Risks and protective factors at individual, family, and community levels that may be associated with behavior outcomes were entered stepwise into latent growth curve models, then replaced by cumulative risk and protective indexes, and finally by a combination of levels of risk and protective indexes. Main outcome measures were the trajectories of externalizing, internalizing, total behavior, and attention problems scores from the Child Behavior Checklist (parent). A total of 1022 (73.6%) children had known outcomes. High PCE/OD significantly predicted externalizing, total, and attention problems when considering the balance between risk and protective indexes. Some PCE/OD predicted externalizing and attention problems. OD/no PCE also predicted behavior outcomes except for internalizing behavior. High level of protective factors was associated with declining trajectories of problem behavior scores over time, independent of drug exposure and risk index scores. High PCE/OD is a significant risk for behavior problems in adolescence; protective factors may attenuate its detrimental effects. Clinical practice and public health policies should consider enhancing protective factors while minimizing risks to improve outcomes of drug-exposed children.

Quantitative Metabolomic Analysis of Urinary Citrulline and Calcitroic Acid in Mice after Exposure to Various Types of Ionizing Radiation.

PubMed

Goudarzi, Maryam; Chauthe, Siddheshwar; Strawn, Steven J; Weber, Waylon M; Brenner, David J; Fornace, Albert J

2016-05-20

With the safety of existing nuclear power plants being brought into question after the Fukushima disaster and the increased level of concern over terrorism-sponsored use of improvised nuclear devices, it is more crucial to develop well-defined radiation injury markers in easily accessible biofluids to help emergency-responders with injury assessment during patient triage. Here, we focused on utilizing ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to identify and quantitate the unique changes in the urinary excretion of two metabolite markers, calcitroic acid and citrulline, in mice induced by different forms of irradiation; external γ irradiation at a low dose rate (LDR) of 3.0 mGy/min and a high dose rate (HDR) of 1.1 Gy/min, and internal exposure to Cesium-137 ((137)Cs) and Strontium-90 ((90)Sr). The multiple reaction monitoring analysis showed that, while exposure to (137)Cs and (90)Sr induced a statistically significant and persistent decrease, similar doses of external γ beam at the HDR had the opposite effect, and the LDR had no effect on the urinary levels of these two metabolites. This suggests that the source of exposure and the dose rate strongly modulate the in vivo metabolomic injury responses, which may have utility in clinical biodosimetry assays for the assessment of exposure in an affected population. This study complements our previous investigations into the metabolomic profile of urine from mice internally exposed to (90)Sr and (137)Cs and to external γ beam radiation.

10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

Code of Federal Regulations, 2012 CFR

2012-01-01

... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. C Appendix C to Part 835—Derived Air... Material a. The data presented in appendix C are to be used for controlling occupational exposures in...

10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

Code of Federal Regulations, 2011 CFR

2011-01-01

... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. C Appendix C to Part 835—Derived Air... Material a. The data presented in appendix C are to be used for controlling occupational exposures in...

Radium-226-contaminated drinking water: hypothesis on an exposure pathway in a population with elevated childhood leukemia.

PubMed

Hoffmann, W; Kranefeld, A; Schmitz-Feuerhake, I

1993-10-01

A recent epidemiological survey on childhood malignant disease in the region of Ellweiler, Rheinland-Pfalz, Germany, revealed a significantly increased incidence of childhood leukemia, but observed incidences of lymphoma and solid tumors were normal. Established risk factors such as individual exposure to chemicals as well as hereditary genetic disorders were ruled out in interviews with the patients or their families. The general population in the region, however, is subjected to considerable doses of ionizing radiation due to high levels of external gamma radiation and high activities of indoor radon. Radiation-specific chromosome aberrations were found in one of two healthy siblings and one father of leukemia patients as well as in any of three probands living in houses with high indoor radon activities. Radon and natural gamma radiation, however, cannot explain the geographical pattern of the cases. Four out of seven cases were observed in two particular villages near a uranium processing plant. The drinking water of these villages partly came from a small river that was contaminated with radium-226 washed out from the dumps of the uranium plant. Only sparse measurements of 226Ra are available, but derived red bone marrow doses for children in the two villages obtained from a simple radio-ecological model show the significance of the drinking water pathway. Prenatal 226Ra exposure of fetuses due to placental transfer and accumulation may have led to significant doses and may explain the excess cases of childhood leukemia in the region even in quantitative terms.

Computational Fluid Dynamics Modeling of Bacillus anthracis Spore Deposition in Rabbit and Human Respiratory Airways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kabilan, Senthil; Suffield, Sarah R.; Recknagle, Kurtis P.

Three-dimensional computational fluid dynamics and Lagrangian particle deposition models were developed to compare the deposition of aerosolized Bacillus anthracis spores in the respiratory airways of a human with that of the rabbit, a species commonly used in the study of anthrax disease. The respiratory airway geometries for each species were derived from computed tomography (CT) or µCT images. Both models encompassed airways that extended from the external nose to the lung with a total of 272 outlets in the human model and 2878 outlets in the rabbit model. All simulations of spore deposition were conducted under transient, inhalation-exhalation breathing conditionsmore » using average species-specific minute volumes. The highest exposure concentration was modeled in the rabbit based upon prior acute inhalation studies. For comparison, human simulation was also conducted at the same concentration. Results demonstrated that regional spore deposition patterns were sensitive to airway geometry and ventilation profiles. Due to the complex airway geometries in the rabbit nose, higher spore deposition efficiency was predicted in the upper conducting airways compared to the human at the same air concentration of anthrax spores. As a result, higher particle deposition was predicted in the conducting airways and deep lung of the human compared to the rabbit lung due to differences in airway branching pattern. This information can be used to refine published and ongoing biokinetic models of inhalation anthrax spore exposures, which currently estimate deposited spore concentrations based solely upon exposure concentrations and inhaled doses that do not factor in species-specific anatomy and physiology.« less

Internal pigment cells respond to external UV radiation in frogs.

PubMed

Franco-Belussi, Lilian; Nilsson Sköld, Helen; de Oliveira, Classius

2016-05-01

Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation. © 2016. Published by The Company of Biologists Ltd.

10 CFR 835.209 - Concentrations of radioactive material in air.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Section 835.209 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.209 Concentrations of radioactive material in air. (a) The derived air... exposures to airborne radioactive material. (b) The estimation of internal dose shall be based on bioassay...

Expanding Stress Generation Theory: Test of a Transdiagnostic Model

PubMed Central

Conway, Christopher C.; Hammen, Constance; Brennan, Patricia A.

2016-01-01

Originally formulated to understand the recurrence of depressive disorders, the stress generation hypothesis has recently been applied in research on anxiety and externalizing disorders. Results from these investigations, in combination with findings of extensive comorbidity between depression and other mental disorders, suggest the need for an expansion of stress generation models to include the stress generating effects of transdiagnostic pathology as well as those of specific syndromes. Employing latent variable modeling techniques to parse the general and specific elements of commonly co-occurring Axis I syndromes, the current study examined the associations of transdiagnostic internalizing and externalizing dimensions with stressful life events over time. Analyses revealed that, after adjusting for the covariation between the dimensions, internalizing was a significant predictor of interpersonal dependent stress, whereas externalizing was a significant predictor of noninterpersonal dependent stress. Neither latent dimension was associated with the occurrence of independent, or fateful, stressful life events. At the syndrome level, once variance due to the internalizing factor was partialled out, unipolar depression contributed incrementally to the generation of interpersonal dependent stress. In contrast, the presence of panic disorder produced a “stress inhibition” effect, predicting reduced exposure to interpersonal dependent stress. Additionally, dysthymia was associated with an excess of noninterpersonal dependent stress. The latent variable modeling framework used here is discussed in terms of its potential as an integrative model for stress generation research. PMID:22428789

Delayed effects of low level acute irradiation and chronic environmental radioactive contamination on DNA lymphocytes of people living in Dolon, a settlement located in the vicinity of the Semipalatinsk nuclear test site (Kazakhstan).

PubMed

Chenal, C; Legue, F; Nourgalieva, K

2006-10-01

During 42 years several hundred nuclear tests were performed by the former USSR at the Semipalatinsk Test Site (STS, Kazakhstan), of which more than 100 were done in the atmosphere. We report here the late genetic damage of external exposure to radiation and environmental radioactive contamination in people living in Dolon, a small settlement situated in the vicinity of the STS. The comet assay was applied on DNA lymphocytes of 20 exposed women and 32 non-exposed women living at 500 km from the STS. We observed a statistically significant difference between the exposed and control groups for mean tail moment (MTM) and DNA% in the tail. The mean values of all comet assay parameters (MTM, DNA% in the tail and score) were higher in the group of women born before 1949 as compared to those born after 1950, which could reflect an effect of external irradiation in 1949 due to the most contaminating explosion. These results suggest that people exposed 50 years ago to relatively small doses of external irradiation and/or still living in an environment contaminated by small amounts of long life radionuclides, still present DNA damage which is in agreement with other cytogenetical studies performed at the same site, on the same population.

Report on the Peer Review Workshop on Revisions to the Exposure Factors Handbook

EPA Science Inventory

This report highlights issues and conclusions from a workshop convened to gather information from expert reviewers on EPA's Exposure Factors Handbook (the Handbook) (External Review Draft, EPA/600/P-95/002A) published in June 1995. This information will be used by EPA in further ...

Framework for Assessing Health Risk of Environmental Exposure to Children (External Review Draft)

EPA Science Inventory

The draft document, Framework For Assessing Health Risks of Environmental Exposure to Children, can serve as a resource on children's health risk assessment and it addresses the need to provide a comprehensive and consistent framework for considering children in risk asses...

Technical basis for external dosimetry at the Waste Isolation Pilot Plant (WIPP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, E.W.; Wu, C.F.; Goff, T.E.

1993-12-31

The WIPP External Dosimetry Program, administered by Westinghouse Electric Corporation, Waste Isolation Division, for the US Department of Energy (DOE), provides external dosimetry support services for operations at the Waste Isolation Pilot Plant (WIPP) Site. These operations include the receipt, experimentation with, storage, and disposal of transuranic (TRU) wastes. This document describes the technical basis for the WIPP External Radiation Dosimetry Program. The purposes of this document are to: (1) provide assurance that the WIPP External Radiation Dosimetry Program is in compliance with all regulatory requirements, (2) provide assurance that the WIPP External Radiation Dosimetry Program is derived from amore » sound technical base, (3) serve as a technical reference for radiation protection personnel, and (4) aid in identifying and planning for future needs. The external radiation exposure fields are those that are documented in the WIPP Final Safety Analysis Report.« less

White matter microstructural alterations in children with prenatal methamphetamine/polydrug exposure

PubMed Central

Colby, John B.; Smith, Lynne; O’Connor, Mary J.; Bookheimer, Susan Y.; Van Horn, John D.; Sowell, Elizabeth R.

2013-01-01

Little is known about the effects of prenatal methamphetamine exposure on white matter microstructure, and the impact of concomitant alcohol exposure. Diffusion tensor imaging and neurocognitive testing were performed on 21 children with prenatal methamphetamine exposure (age 9.8±1.8 years; 17 also exposed to alcohol), 19 children with prenatal alcohol but not methamphetamine exposure (age 10.8±2.3 years), and 27 typically-developing children (age 10.3±3.3 years). Whole-brain maps of fractional anisotropy (FA) were evaluated using tract-based spatial statistics. Relative to unexposed controls, children with prenatal methamphetamine exposure demonstrated higher FA mainly in left-sided regions, including the left anterior corona radiata (LCR) and corticospinal tract (P<0.05, corrected). Post-hoc analyses of these FA differences showed they likely result more from lower radial diffusivity (RD) than higher axial diffusivity (AD). Relative to the methamphetamine-exposed group, children with prenatal alcohol exposure showed lower FA in frontotemporal regions – particularly the right external capsule (P<0.05, corrected). We failed to find any group-performance interaction (on tests of executive functioning and visuomotor integration) in predicting FA; however, FA in the right external capsule was significantly associated with performance on a test of visuomotor integration across groups (P<0.05). This report demonstrates unique diffusion abnormalities in children with prenatal methamphetamine/polydrug exposure that are distinct from those associated with alcohol exposure alone, and illustrates that these abnormalities in brain microstructure are persistent into childhood and adolescence – long after the polydrug exposure in utero. PMID:23149028

Maternal distress explains the relationship of young African American mothers' violence exposure with their preschoolers' behavior.

PubMed

Mitchell, Stephanie J; Lewin, Amy; Rasmussen, Andrew; Horn, Ivor B; Joseph, Jill G

2011-02-01

Adolescent mothers and their children are particularly susceptible to witnessing or directly experiencing violence. Such violence exposure predicts maternal distress, parenting, and child behavior problems. The current study examined how mothers' depressive symptoms, aggression, harsh disciplinary practices, and home environment independently explain the association between mothers' violence exposure and children's externalizing and internalizing behavior, controlling for their children's violence exposure. Data were collected from 230 African American mothers living in Washington, DC who gave birth as adolescents and whose children were 3 to 5 years old. Path analysis revealed that the effect of mothers' experienced violence on children's externalizing and internalizing behavior was mediated by mothers' depressive symptoms and aggression. However, neither harsh discipline nor stimulation in the home environment acted as significant mediators, and there were no direct or indirect effects of mothers' witnessed violence on child behavior. This study builds on previous work by identifying an association between maternal violence exposure and children's behavior, independent of children's own violence exposure that is explained by mothers' increased distress but not their parenting. These findings suggest that a potential means of preventing behavior problems in minority children born to adolescent mothers is to identify mothers who have been directly exposed to violence and treat their depressive symptoms and aggressive behaviors.

Effects of Continuous Gamma-Ray Exposure In Utero in B6C3F1 Mice on Gestation Day 18 and at 10 Weeks of Age.

PubMed

Gulay, K C M; Tanaka, I B; Komura, J; Tanaka, S

2018-04-01

Pregnant C57BL/6JJcl mice were exposed to γ rays at low dose rate (20 mGy/day, LDR) or medium dose rate (200 and 400 mGy/day, MDR) from gestation day (GD) 0-18 to total accumulated doses of 360, 3,600 and 7,200 mGy, respectively. An additional group of pregnant mice were acutely exposed to 2 Gy at high dose rate (HDR) of 0.77 Gy/min on GD 11. In experiment 1, fetuses collected via cesarean section on GD 18 were examined for external and skeletal abnormalities. While the results of LDR exposure (20 mGy/day) did not significantly differ from the nonirradiated controls in all parameters examined, MDR (200 and 400 mGy/day) and acute HDR (2 Gy) exposure caused growth retardation and significantly increased incidence of unossified bones. Increased incidence of external abnormalities was observed only in the acute HDR group. In experiment 2, the dams were allowed to give birth and the pups were clinically monitored and weighed periodically until 10 weeks of age when they were sacrificed and subjected to pathological examination. Pups exposed at MDRs of 200 and 400 mGy/dayand at acute HDR of 0.77 Gy/min had lower bodyweights from weaning (3 weeks) to 10 weeks of age except for females exposed to 400 mGy/day MDR. None of the pups exposed to an acute 2 Gy dose on GD 11 survived to 10 weeks of age. Histopathological changes were not significantly different between the nonirradiated control and the 20 mGy/day LDR groups. However, at both MDR exposures of 200 and 400 mGy/day. gonadal (testes and ovary) hypoplasia/atrophy was observed in all the 10-week-old pups. Our results show that in utero LDR exposure to 20 mGy/day for the entire gestation period did not cause any significant effect in pups when compared to the nonirradiated controls up to 10 weeks of age. However, pups exposed in utero to MDRs showed dose-related growth retardation with delayed ossifications (400 mGy/day) and gonadal hypoplasia/atrophy. These findings suggest that increased post-implantation loss in dams exposed at MDR is due to early embryonic deaths resulting in early resorption.

Exposure to Violence, Social Information Processing, and Problem Behavior in Preschool Children

PubMed Central

Ziv, Yair

2012-01-01

Understanding the mechanisms by which early risk factors for social maladjustment contribute to disruptive behaviors in social settings is vital to developmental research and practice. A major risk factor for social maladjustment is early exposure to violence which was examined in this short-term longitudinal study in relation to social information processing patterns and externalizing and internalizing behaviors in a sample of 256 preschool children. Data on exposure to violence were obtained via parent report, data on social information processing were obtained via child interview, and data on child problem behavior were obtained via teacher report. Findings supported the hypothesis that, compared to children not exposed to violence, children reported to witness and/or experience violence are more likely to attribute hostile intent to peers, generate aggressive responses, and evaluate socially unaccepted responses (aggressive and inept) as socially suitable. The former were also found to exhibit higher levels of externalizing and internalizing behaviors. Finally, social information processing mediated the link between exposure to violence and problem behavior thus supporting this study’s general approach which argues that the link between exposure to violence and children’s problem behaviors are better understood within the context of their perceptions about social relationships. PMID:23011955

Exposure to violence, social information processing, and problem behavior in preschool children.

PubMed

Ziv, Yair

2012-01-01

Understanding the mechanisms by which early risk factors for social maladjustment contribute to disruptive behaviors in social settings is vital to developmental research and practice. A major risk factor for social maladjustment is early exposure to violence, which was examined in this short-term longitudinal study in relation to social information processing (SIP) patterns and externalizing and internalizing behaviors in a sample of 256 preschool children. Data on exposure to violence were obtained via parent report, data on SIP were obtained via child interview, and data on child problem behavior were obtained via teacher report. Findings supported the hypothesis that, compared to children not exposed to violence, children reported to witness and/or experience violence are more likely to attribute hostile intent to peers, generate aggressive responses, and evaluate socially unaccepted responses (aggressive and inept) as socially suitable. The former were also found to exhibit higher levels of externalizing and internalizing behaviors. Finally, SIP mediated the link between exposure to violence and problem behavior thus supporting this study's general approach, which argues that the link between exposure to violence and children's problem behaviors are better understood within the context of their perceptions about social relationships. © 2012 Wiley Periodicals, Inc.

Assessment of the magnetic field exposure due to the battery current of digital mobile phones.

PubMed

Jokela, Kari; Puranen, Lauri; Sihvonen, Ari-Pekka

2004-01-01

Hand-held digital mobile phones generate pulsed magnetic fields associated with the battery current. The peak value and the waveform of the battery current were measured for seven different models of digital mobile phones, and the results were applied to compute approximately the magnetic flux density and induced currents in the phone-user's head. A simple circular loop model was used for the magnetic field source and a homogeneous sphere consisting of average brain tissue equivalent material simulated the head. The broadband magnetic flux density and the maximal induced current density were compared with the guidelines of ICNIRP using two various approaches. In the first approach the relative exposure was determined separately at each frequency and the exposure ratios were summed to obtain the total exposure (multiple-frequency rule). In the second approach the waveform was weighted in the time domain with a simple low-pass RC filter and the peak value was divided by a peak limit, both derived from the guidelines (weighted peak approach). With the maximum transmitting power (2 W) the measured peak current varied from 1 to 2.7 A. The ICNIRP exposure ratio based on the current density varied from 0.04 to 0.14 for the weighted peak approach and from 0.08 to 0.27 for the multiple-frequency rule. The latter values are considerably greater than the corresponding exposure ratios 0.005 (min) to 0.013 (max) obtained by applying the evaluation based on frequency components presented by the new IEEE standard. Hence, the exposure does not seem to exceed the guidelines. The computed peak magnetic flux density exceeded substantially the derived peak reference level of ICNIRP, but it should be noted that in a near-field exposure the external field strengths are not valid indicators of exposure. Currently, no biological data exist to give a reason for concern about the health effects of magnetic field pulses from mobile phones.

Crystalline silica exposure and lung cancer mortality in diatomaceous earth industry workers: a quantitative risk assessment.

PubMed

Rice, F L; Park, R; Stayner, L; Smith, R; Gilbert, S; Checkoway, H

2001-01-01

To use various exposure-response models to estimate the risk of mortality from lung cancer due to occupational exposure to respirable crystalline silica dust. Data from a cohort mortality study of 2342 white male California diatomaceous earth mining and processing workers exposed to crystalline silica dust (mainly cristobalite) were reanalyzed with Poisson regression and Cox's proportional hazards models. Internal and external adjustments were used to control for potential confounding from the effects of time since first observation, calendar time, age, and Hispanic ethnicity. Cubic smoothing spline models were used to assess the fit of the models. Exposures were lagged by 10 years. Evaluations of the fit of the models were performed by comparing their deviances. Lifetime risks of lung cancer were estimated up to age 85 with an actuarial approach that accounted for competing causes of death. Exposure to respirable crystalline silica dust was a significant predictor (p<0.05) in nearly all of the models evaluated and the linear relative rate model with a 10 year exposure lag seemed to give the best fit in the Poisson regression analysis. For those who died of lung cancer the linear relative rate model predicted rate ratios for mortality from lung cancer of about 1.6 for the mean cumulative exposure to respirable silica compared with no exposure. The excess lifetime risk (to age 85) of mortality from lung cancer for white men exposed for 45 years and with a 10 year lag period at the current Occupational Safety and Health Administration (OSHA) standard of about 0.05 mg/m(3) for respirable cristobalite dust is 19/1000 (95% confidence interval (95% CI) 5/1000 to 46/1000). There was a significant risk of mortality from lung cancer that increased with cumulative exposure to respirable crystalline silica dust. The predicted number of deaths from lung cancer suggests that current occupational health standards may not be adequately protecting workers from the risk of lung cancer.

External auditory canal stenosis due to the use of powdered boric acid.

PubMed

Dündar, Riza; Soy, Fatih Kemal; Kulduk, Erkan; Muluk, Nuray Bayar; Cingi, Cemal

2014-09-01

Acquired stenosis of the external auditory canal (EAC) may occur because of chronic external otitis, recurrent chronic catarrhal otitis media associated with tympanic membrane perforation, chronic dermatitis, tumors, and trauma. Stenosis occurs generally at the one-third bone part of the external auditory canal. In this article, we present 3 cases of acquired EAC stenosis due to the previous powdered boric acid application. Besides the presentation of surgical intervetions in these cases, we want to notify the physicians not to use or carefully use powdered boric acid because of the complication of EAC stenosis.

Genetic and environmental influences on externalizing behavior and alcohol problems in adolescence: A female twin study

PubMed Central

Knopik, Valerie S.; Heath, Andrew C.; Bucholz, Kathleen K.; Madden, Pamela A.F.; Waldron, Mary

2009-01-01

Genetic and environmental contributions to the observed correlations among DSM-IV ADHD problems [inattentive (INATT) and hyperactive/impulsive (HYP/IMP) behaviors], conduct problems (CDP) and alcohol problems (AlcProb) were examined by fitting multivariate structural equation models to data from the Missouri Adolescent Female Twin Study [N=2892 twins (831 monozygotic pairs, 615 dizygotic pairs)]. Based on results of preliminary regression models, we modified the structural model to jointly estimate (i) the regression of each phenotype on significant familial/prenatal predictors, and (ii) genetic and environmental contributions to the residual variance and covariance. Results suggested that (i) parental risk factors, such as parental alcohol dependence and regular smoking, increase risk for externalizing behavior; (ii) prenatal exposures predicted increased symptomatology for HYP/IMP (smoking during pregnancy), INATT and CDP (prenatal alcohol exposure); (iii) after adjusting for measured familial/prenatal risk factors, genetic influences were significant for HYP/IMP, INATT, and CDP; however, similar to earlier reports, genetic effects on alcohol dependence symptoms were negligible; and (iv) in adolescence, correlated liabilities for conduct and alcohol problems are found in environmental factors common to both phenotypes, while covariation among impulsivity, inattention, and conduct problems is primarily due to genetic influences common to these three behaviors. Thus, while a variety of adolescent problem behaviors are significantly correlated, the structure of that association may differ as a function of phenotype (e.g., comorbid HYP/IMP and CDP vs. comorbid CDP and AlcProb), a finding that could inform different approaches to treatment and prevention. PMID:19341765

External lead contamination of women's nails by surma in Pakistan: Is the biomarker reliable?

PubMed

Ikegami, Akihiko; Takagi, Mai; Fatmi, Zafar; Kobayashi, Yayoi; Ohtsu, Mayumi; Cui, Xiaoyi; Mise, Nathan; Mizuno, Atsuko; Sahito, Ambreen; Khoso, Aneeta; Kayama, Fujio

2016-11-01

Adverse health effects of heavy metals are a public health concern, especially lead may cause negative health impacts to human fetal and infantile development. The lead concentrations in Pakistani pregnant women's nails, used as a biomarker, were measured to estimate the lead exposure. Thirteen nail samples out of 84 nails analyzed contained lead higher than the concentration (13.6 μg/g) of the fatal lead poisoning case, raising the possibility of an external contamination. Eye cosmetics such as surma are recognized as one of the important sources of lead exposure in Pakistan. We collected in Pakistan 30 eye cosmetics made in Pakistan, Saudi Arabia and western countries. As the metal composition analysis by energy dispersive X-ray fluorescence spectrometry revealed that some surma samples contained lead more than 96%, the surma might contaminate the nail specimen. Scanning electron microscopy observations showed that lead-containing surma consists of fine particle of galena (ore of lead sulfide) in respirable dust range (less than 10 μm). In addition, relative in vitro bioavailability of lead in the surma was determined as 5.2%. Thus, lead-containing surma consists of inhalable and bioavailable particles, and it contributes an increased risk of lead exposure. Moreover, the relationship between the surma and the lead-contaminated nails by lead isotope ratios analysis indicated the potential of lead contamination in nails by surma. These results suggest that lead in the nails was derived both from body burden of lead and external contamination by lead-containing surma. Therefore, nail is not suited as a biomarker for lead exposure in the countries where surma used, because we may overestimate lead exposure by surface lead contamination in the nail by surma. Copyright © 2016 Elsevier Ltd. All rights reserved.

Robustness and Radiation Resistance of the Pale Grass Blue Butterfly from Radioactively Contaminated Areas: A Possible Case of Adaptive Evolution.

PubMed

Nohara, Chiyo; Hiyama, Atsuki; Taira, Wataru; Otaki, Joji M

2018-02-14

The pale grass blue butterfly, Zizeeria maha, has been used to evaluate biological impacts of the Fukushima nuclear accident in March 2011. Here, we examined the possibility that butterflies have adapted to be robust in the contaminated environment. Larvae (n = 2432) were obtained from adult butterflies (n = 20) collected from 7 localities with various contamination levels in May 2012, corresponding to the 7th generation after the accident. When the larvae were reared on non-contaminated host plant leaves from Okinawa, the normality rates of natural exposure without artificial irradiation (as an indication of robustness) were high not only in the least contaminated locality but also in the most contaminated localities. The normality rates were similarly obtained when the larvae were reared on non-contaminated leaves with external irradiation or on contaminated leaves from Fukushima to deliver internal irradiation. The normality rate of natural exposure and that of external or internal exposure were correlated, suggesting that radiation resistance (or susceptibility) likely reflects general state of health. The normality rate of external or internal exposure was divided by the relative normality rate of natural exposure, being defined as the resistance value. The resistance value was the highest in the populations of heavily contaminated localities and was inversely correlated with the distance from the Fukushima Dai-ichi nuclear power plant. These results suggest that the butterfly population might have adapted to the contaminated environment within approximately 1 year after the accident. The present study may partly explain the decrease in mortality and abnormality rates later observed in the contaminated areas. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Evaluation of seals and lubricants used on the Long Duration Exposure Facility

NASA Technical Reports Server (NTRS)

Dursch, H. W.; Keough, B. K.; Pippin, H. G.

1994-01-01

This report described results from testing and analysis of seals and lubricants subsequent to the 69-month low-earth-orbit (LEO) exposure on the Long Duration Exposure Facility (LDEF). Results show that if the materials were shielded from exposure to LDEF's external environment, the 69-month exposure to LEO resulted in minimal changes to material properties. However, if the materials were exposed to LDEF's exterior environments (atomic oxygen, solar radiation, meteoroids, and/or space debris), a variety of events occurred, ranging from no material change, to changes in properties, to significant erosion of the material.

Roles of children and their parents in the reduction of radiation risk after the 2011 Fukushima Daiichi Nuclear Power Plant accident

PubMed Central

Kitamura, Akiko

2017-01-01

Introduction On March 11, 2011, Japan experienced its largest recorded earthquake with a magnitude of 9.0. The resulting tsunami caused massive damage to the Fukushima Daiichi Nuclear Power Plant reactors, and the surrounding environment was contaminated with radioactive materials. During this period, some residents were exposed to high levels of radiation (up to 5 millisieverts [mSv]), but since then, many residents have been exposed to low levels of radiation (<1 mSv). This study was conducted to assess the effects of lifestyle and attitude factors on external radiation exposure among Fukushima residents. Methods This community-based, cross-sectional study was conducted in Nihonmatsu City of the Fukushima Prefecture from May to July 2014. The population survey targeted 6,884 children between the ages of 0–15 years, and a personal radiation badge and questionnaire were administered to each of the residences. Multiple linear regression analysis was used to assess the impact of lifestyle and attitude factors on external radiation dose. Results The study participants (population size [n] = 4,571) had an additional mean radiation dose of 0.65 mSv/year, which is small as compared to the mean radiation dose 6 months after the disaster (1.5 mSv/year), in 2012 (1.5 mSv/year), and in 2013 (1.0 mSv/year). External radiation doses statistically varied by socio-demographic and lifestyle factors. Participants living in wooden residences (p-value<0.001) and within 100 meters of a forest (p = 0.001) had higher radiation exposure. Conversely, participants with a cautious attitude towards radiation had lower radiation exposure (beta [b] = -0.124, p = 0.003). Conclusion Having a cautious attitude towards radiation and being aware of exposure risks proved to be significant in the reduction of external radiation dose. Therefore, in the event of future radiation disasters, attitudes towards and awareness of radiation should be considered in the reduction of exposure risk and implementation of radiation protection. PMID:29236725

Determining eyeball surface area directly exposed to the effects of external factors.

PubMed

Juliszewski, Tadeusz; Kadłuczka, Filip; Kiełbasa, Paweł

2016-01-01

This article discusses determining the surface area of eyeballs of men and women exposed to the direct effects of external factors in the working environment. For one eye, the mean surface is 172-182 mm(2). The determined surface area can be used in formulas for calculating the exposure of eyeballs to harmful chemical substances in workplace air.

Perceptions of Self-Determination by Special Education and Rehabilitation Practitioners Based on Viewing a Self-Directed IEP versus an External-Directed IEP Meeting

ERIC Educational Resources Information Center

Branding, Dave; Bates, Paul; Miner, Craig

2009-01-01

This study investigated perception of self-determination by special education and rehabilitation practitioners following their exposure to a videotaped simulation of a self-directed IEP meeting and an external-directed IEP meeting involving an adolescent with mild mental retardation. Groups of special education practitioners and rehabilitation…

Fetal cyclophosphamide exposure induces testicular cancer and reduced spermatogenesis and ovarian follicle numbers in mice.

PubMed

Comish, Paul B; Drumond, Ana Luiza; Kinnell, Hazel L; Anderson, Richard A; Matin, Angabin; Meistrich, Marvin L; Shetty, Gunapala

2014-01-01

Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT) and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP) is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1) mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2%) and to 80% in the male offspring of L1 (control value 33%). These increases are similar to those observed in both lines of mice by radiation. In utero exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼ 70% of control and induced atrophic seminiferous tubules in ∼ 30% of the testes. When the in utero CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i) DNA damage is a common mechanism leading to induction of testicular cancer, ii) increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii) children exposed to radiation or DNA damaging chemotherapeutic agents in utero may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan.

Fetal Cyclophosphamide Exposure Induces Testicular Cancer and Reduced Spermatogenesis and Ovarian Follicle Numbers in Mice

PubMed Central

Comish, Paul B.; Drumond, Ana Luiza; Kinnell, Hazel L.; Anderson, Richard A.; Matin, Angabin; Meistrich, Marvin L.; Shetty, Gunapala

2014-01-01

Exposure to radiation during fetal development induces testicular germ cell tumors (TGCT) and reduces spermatogenesis in mice. However, whether DNA damaging chemotherapeutic agents elicit these effects in mice remains unclear. Among such agents, cyclophosphamide (CP) is currently used to treat breast cancer in pregnant women, and the effects of fetal exposure to this drug manifested in the offspring must be better understood to offer such patients suitable counseling. The present study was designed to determine whether fetal exposure to CP induces testicular cancer and/or gonadal toxicity in 129 and in 129.MOLF congenic (L1) mice. Exposure to CP on embryonic days 10.5 and 11.5 dramatically increased TGCT incidence to 28% in offspring of 129 mice (control value, 2%) and to 80% in the male offspring of L1 (control value 33%). These increases are similar to those observed in both lines of mice by radiation. In utero exposure to CP also significantly reduced testis weights at 4 weeks of age to ∼70% of control and induced atrophic seminiferous tubules in ∼30% of the testes. When the in utero CP-exposed 129 mice reached adulthood, there were significant reductions in testicular and epididymal sperm counts to 62% and 70%, respectively, of controls. In female offspring, CP caused the loss of 77% of primordial follicles and increased follicle growth activation. The results indicate that i) DNA damage is a common mechanism leading to induction of testicular cancer, ii) increased induction of testis cancer by external agents is proportional to the spontaneous incidence due to inherent genetic susceptibility, and iii) children exposed to radiation or DNA damaging chemotherapeutic agents in utero may have increased risks of developing testis cancer and having reduced spermatogenic potential or diminished reproductive lifespan. PMID:24691397

COMMON ISSUES IN HUMAN AND ECOSYSTEM EXPOSURE ASSESSMENT: THE SIGNIFICANCE OF PARTITIONING, KINETICS, AND UPTAKE AT BIOLOGICAL EXCHANGE SURFACES

EPA Science Inventory

Exogenous chemicals enter organisms through critical surfaces in the lung, gills, gut, and skin. Transfer across these boundaries is the first step in characterizing the ratio of tissue dose to external exposure. Surface processes and fugacity are important elements of both human...

Treatment of Challenging Behavior Exhibited by Children with Prenatal Drug Exposure

ERIC Educational Resources Information Center

Kurtz, Patricia F.; Chin, Michelle D.; Rush, Karena S.; Dixon, Dennis R.

2008-01-01

A large body of literature exists describing the harmful effects of prenatal drug exposure on infant and child development. However, there is a paucity of research examining strategies to ameliorate sequelae such as externalizing behavior problems. In the present study, functional analysis procedures were used to assess challenging behavior…

Memoranda Associated with the Second External Review Draft of Health Risk and Exposure Assessments from the Current Review of Ozone NAAQS

EPA Pesticide Factsheets

EPA's Health and Environmental Impacts Division had to make corrections to some of the risk results included in earlier drafts of the Health Risk and Exposure Assessment from the current review of ozone national ambient air quality standards (NAAQS).

Dosimetric calculations for uranium miners for epidemiological studies.

PubMed

Marsh, J W; Blanchardon, E; Gregoratto, D; Hofmann, W; Karcher, K; Nosske, D; Tomásek, L

2012-05-01

Epidemiological studies on uranium miners are being carried out to quantify the risk of cancer based on organ dose calculations. Mathematical models have been applied to calculate the annual absorbed doses to regions of the lung, red bone marrow, liver, kidney and stomach for each individual miner arising from exposure to radon gas, radon progeny and long-lived radionuclides (LLR) present in the uranium ore dust and to external gamma radiation. The methodology and dosimetric models used to calculate these organ doses are described and the resulting doses for unit exposure to each source (radon gas, radon progeny and LLR) are presented. The results of dosimetric calculations for a typical German miner are also given. For this miner, the absorbed dose to the central regions of the lung is dominated by the dose arising from exposure to radon progeny, whereas the absorbed dose to the red bone marrow is dominated by the external gamma dose. The uncertainties in the absorbed dose to regions of the lung arising from unit exposure to radon progeny are also discussed. These dose estimates are being used in epidemiological studies of cancer in uranium miners.

Impacts of ocean acidification on sperm develop with exposure time for a polychaete with long lived sperm.

PubMed

Campbell, Anna L; Ellis, Robert P; Urbina, Mauricio A; Mourabit, Sulayman; Galloway, Tamara S; Lewis, Ceri

2017-08-01

The majority of marine invertebrate species release eggs and sperm into seawater for external fertilisation. Seawater conditions are currently changing at an unprecedented rate as a consequence of ocean acidification (OA). Sperm are thought to be particularly vulnerable to these changes and may be exposed to external environmental conditions for variable periods of time between spawning and fertilisation. Here, we undertook a mechanistic investigation of sperm swimming performance in the coastal polychaete Arenicola marina during an extended exposure to OA conditions (pH NBS 7.77, 1000 μatm pCO 2 ). We found that key fitness-related aspects of sperm functioning declined faster under OA conditions i.e. impacts became apparent with exposure time. Sperm swimming speed (VCL), the number of motile sperm and sperm path linearity all dropped significantly after 4 h under OA conditions whilst remaining constant under ambient conditions at this time point. Our results highlight the importance of sperm exposure duration in ocean acidification experiments and may help towards explaining species specific differences in response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Psychosocial Consequences of Caregiver Transitions for Maltreated Youth Entering Foster Care: The Moderating Impact of Community Violence Exposure

PubMed Central

Garrido, Edward F.; Culhane, Sara E.; Petrenko, Christie L. M.; Taussig, Heather N.

2011-01-01

Youth who experience a greater number of caregiver transitions during childhood are at risk for developing a host of psychosocial problems. Although researchers have examined individual-level factors that may moderate this association, no known studies have examined the impact of community-level factors. The current study investigated whether community violence exposure moderated the association between number of prior caregiver transitions and increases in levels of externalizing and internalizing problems for a sample of youth entering foster care. Participants included 156 youth (age 9 to 11 at first assessment) removed from their homes because of maltreatment. Youth provided reports of caregiver transitions and community violence exposure at baseline, and caregivers, teachers, and youth reported on externalizing and internalizing problems 18–22 months later. Results from hierarchical multiple regression analyses indicated that youth with a greater number of caregiver transitions and higher levels of community violence exposure evidenced significant increases in levels of psychosocial problems. The results of the study are discussed in terms of their implications for child welfare services. PMID:21729018

Analysis of radiation exposure for naval units of Operation Crossroads. Volume 3. (Appendix B) support ships. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weitz, R.; Thomas, C.; Klemm, J.

1982-03-03

External radiation doses are reconstructed for crews of support and target ships of Joint Task Force One at Operation CROSSROADS, 1946. Volume I describes the reconstruction methodology, which consists of modeling the radiation environment, to include the radioactivity of lagoon water, target ships, and support ship contamination; retracing ship paths through this environment; and calculating the doses to shipboard personnel. The USS RECLAIMER, a support ship, is selected as a representative ship to demonstrate this methodology. Doses for all other ships are summarized. Volume II (Appendix A) details the results for target ship personnel. Volume III (Appendix B) details themore » results for support ship personnel. Calculated doses for more than 36,000 personnel aboard support ships while at Bikini range from zero to 1.7 rem. Of those approximately 34,000 are less than 0.5 rem. From the models provided, doses due to target ship reboarding and doses accrued after departure from Bikini can be calculated, based on the individual circumstances of exposure.« less

Analysis of radiation exposure for naval units of Operation Crossroads. Volume 2. (Appendix A) target ships. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weitz, R.; Thomas, C.; Klemm, J.

1982-03-03

External radiation doses are reconstructed for crews of support and target ships of Joint Task Force One at Operation CROSSROADS, 1946. Volume I describes the reconstruction methodology, which consists of modeling the radiation environment, to include the radioactivity of lagoon water, target ships, and support ship contamination; retracing ship paths through this environment; and calculating the doses to shipboard personnel. The USS RECLAIMER, a support ship, is selected as a representative ship to demonstrate this methodology. Doses for all other ships are summarized. Volume II (Appendix A) details the results for target ship personnel. Volume III (Appendix B) details themore » results for support ship personnel. Calculated doses for more than 36,000 personnel aboard support ships while at Bikini range from zero to 1.7 rem. Of those, approximately 34,000 are less than 0.5 rem. From the models provided, doses due to target ship reboarding and doses accrued after departure from Bikini can be calculated, based on the individual circumstances of exposure.« less

High- to low-dose extrapolation: critical determinants involved in the dose response of carcinogenic substances.

PubMed

Swenberg, J A; Richardson, F C; Boucheron, J A; Deal, F H; Belinsky, S A; Charbonneau, M; Short, B G

1987-12-01

Recent investigations on mechanism of carcinogenesis have demonstrated important quantitative relationships between the induction of neoplasia, the molecular dose of promutagenic DNA adducts and their efficiency for causing base-pair mismatch, and the extent of cell proliferation in target organ. These factors are involved in the multistage process of carcinogenesis, including initiation, promotion, and progression. The molecular dose of DNA adducts can exhibit supralinear, linear, or sublinear relationships to external dose due to differences in absorption, biotransformation, and DNA repair at high versus low doses. In contrast, increased cell proliferation is a common phenomena that is associated with exposures to relatively high doses of toxic chemicals. As such, it enhances the carcinogenic response at high doses, but has little effect at low doses. Since data on cell proliferation can be obtained for any exposure scenario and molecular dosimetry studies are beginning to emerge on selected chemical carcinogens, methods are needed so that these critical factors can be utilized in extrapolation from high to low doses and across species. The use of such information may provide a scientific basis for quantitative risk assessment.

High- to low-dose extrapolation: critical determinants involved in the dose response of carcinogenic substances.

PubMed Central

Swenberg, J A; Richardson, F C; Boucheron, J A; Deal, F H; Belinsky, S A; Charbonneau, M; Short, B G

1987-01-01

Recent investigations on mechanism of carcinogenesis have demonstrated important quantitative relationships between the induction of neoplasia, the molecular dose of promutagenic DNA adducts and their efficiency for causing base-pair mismatch, and the extent of cell proliferation in target organ. These factors are involved in the multistage process of carcinogenesis, including initiation, promotion, and progression. The molecular dose of DNA adducts can exhibit supralinear, linear, or sublinear relationships to external dose due to differences in absorption, biotransformation, and DNA repair at high versus low doses. In contrast, increased cell proliferation is a common phenomena that is associated with exposures to relatively high doses of toxic chemicals. As such, it enhances the carcinogenic response at high doses, but has little effect at low doses. Since data on cell proliferation can be obtained for any exposure scenario and molecular dosimetry studies are beginning to emerge on selected chemical carcinogens, methods are needed so that these critical factors can be utilized in extrapolation from high to low doses and across species. The use of such information may provide a scientific basis for quantitative risk assessment. PMID:3447904

Comparing Virtual Reality Exposure Therapy to Prolonged Exposure in the Treatment of Soldiers with PTSD

DTIC Science & Technology

2014-06-01

Type I alpha should be discussed in relation to the findings for multiple primary hypothesis tests conducted . o The hypotheses indicated in the...memory during exposure. However, there is limited research on the effectiveness of either treatment with active duty military personnel and there are...VRE or were assigned to a minimal attention wait list. All assessments were conducted by a psychologist blind to treatment group. External

Blood-borne biomarkers and bioindicators for linking exposure to health effects in environmental health science.

PubMed

Wallace, M Ariel Geer; Kormos, Tzipporah M; Pleil, Joachim D

2016-01-01

Environmental health science aims to link environmental pollution sources to adverse health outcomes to develop effective exposure intervention strategies that reduce long-term disease risks. Over the past few decades, the public health community recognized that health risk is driven by interaction between the human genome and external environment. Now that the human genetic code has been sequenced, establishing this "G × E" (gene-environment) interaction requires a similar effort to decode the human exposome, which is the accumulation of an individual's environmental exposures and metabolic responses throughout the person's lifetime. The exposome is composed of endogenous and exogenous chemicals, many of which are measurable as biomarkers in blood, breath, and urine. Exposure to pollutants is assessed by analyzing biofluids for the pollutant itself or its metabolic products. New methods are being developed to use a subset of biomarkers, termed bioindicators, to demonstrate biological changes indicative of future adverse health effects. Typically, environmental biomarkers are assessed using noninvasive (excreted) media, such as breath and urine. Blood is often avoided for biomonitoring due to practical reasons such as medical personnel, infectious waste, or clinical setting, despite the fact that blood represents the central compartment that interacts with every living cell and is the most relevant biofluid for certain applications and analyses. The aims of this study were to (1) review the current use of blood samples in environmental health research, (2) briefly contrast blood with other biological media, and (3) propose additional applications for blood analysis in human exposure research.

Impact of the home environment on the relationship between prenatal exposure to environmental tobacco smoke and child behavior.

PubMed

Hopson, Madeleine B; Margolis, Amy; Rauh, Virginia; Herbstman, Julie

2016-01-01

The goal of this study was to ascertain whether the effect of prenatal ETS exposure on behavioral symptoms at age 7 years is modified by the quality of the home environment. In a cohort of 417 children enrolled in a longitudinal birth cohort in New York City, prenatal ETS exposure, child behavior and home environment were assessed. Prenatal ETS was measured by questionnaire and blood cotinine. Child Behavior Checklist (CBCL) and Early Childhood HOME Inventory Scale (HOME) were also used. We detected a significant interaction between prenatal ETS exposure and living in a "better" home environment on reported problems in the rule breaking and externalizing domains (p-value for interaction terms: 0.002 and 0.04, respectively), such that there was no significant adverse impact of ETS exposure on behavior among those who experienced a "better" environment. We also detected a significant interaction between prenatal ETS exposure and living in a "worse" home environment on reported problems in the aggressive and externalizing domains (p-value for interaction terms: 0.03 and 0.02, respectively), such that there was a significant adverse effect of ETS exposure on behavior among children who experienced a "worse" environment. Aspects of the HOME environment, both positive and negative, moderated the effects of prenatal ETS exposure on selected behaviors at 7 years of age. This finding suggests that some negative developmental behavioral effects associated with ETS exposure early in life may be modified by the provision of an enriched learning environment as measured by the HOME inventory.

Prenatal alcohol and other early childhood adverse exposures: Direct and indirect pathways to adolescent drinking

PubMed Central

Cornelius, Marie D.; De Genna, Natacha M.; Goldschmidt, Lidush; Larkby, Cynthia; Day, Nancy L.

2016-01-01

We examined direct and indirect pathways between adverse environmental exposures during gestation and childhood and drinking in mid-adolescence. Mothers and their offspring (n = 917 mother/child dyads) were followed prospectively from second trimester to a 16-year follow-up assessment. Interim assessments occurred at delivery, 6, 10, and 14 years. Adverse environmental factors included gestational exposures to alcohol, tobacco, and marijuana, exposures to childhood maltreatment and violence, maternal psychological symptoms, parenting practices, economic and home environments, and demographic characteristics of the mother and child. Indirect effects of early child behavioral characteristics including externalizing, internalizing activity, attention, and impulsivity were also examined. Polytomous logistic regression analyses were used to evaluate direct effects of adverse environmental exposures with level of adolescent drinking. Structural equation modeling (SEM) was applied to simultaneously estimate the relation between early adversity variables, childhood characteristics, and drinking level at age 16 while controlling for significant covariates. Level of drinking among the adolescent offspring was directly predicted by prenatal exposure to alcohol, less parental strictness, and exposures to maltreatment and violence during childhood. Whites and offspring with older mothers were more likely to drink at higher levels. There was a significant indirect effect between childhood exposure to violence and adolescent drinking via childhood externalizing behavior problems. All other hypothesized indirect pathways were not significant. Thus most of the early adversity measures directly predicted adolescent drinking and did not operate via childhood behavioral dysregulation characteristics. These results highlight the importance of adverse environmental exposures on pathways to adolescent drinking. PMID:26994529

[Evaluation of radiation exposure of personnel in an orthopaedic and trauma operation theatre using the new real-time dosimetry system "dose aware"].

PubMed

Müller, M C; Strauss, A; Pflugmacher, R; Nähle, C P; Pennekamp, P H; Burger, C; Wirtz, D C

2014-08-01

There is a positive correlation between operation time and staff exposure to radiation during intraoperative use of C-arm fluoroscopy. Due to harmful effects of exposure to long-term low-dose radiation for both the patient and the operating team it should be kept to a minimum. AIM of this study was to evaluate a novel dosimeter system called Dose Aware® (DA) enabling radiation exposure feedback of the personal in an orthopaedic and trauma operation theatre in real-time. Within a prospective study over a period of four month, DA was applied by the operation team during 104 orthopaedic and trauma operations in which the C-arm fluoroscope was used in 2D-mode. During ten operation techniques, radiation exposure of the surgeon, the first assistant, the theatre nurse and the anaesthesiologist was evaluated. Seventy-three operations were analysed. The surgeon achieved the highest radiation exposure during dorsolumbar spinal osteosynthesis, kyphoplasty and screw fixation of sacral fractures. The first assistant received a higher radiation exposure compared to the surgeon during plate osteosynthesis of distal radius fractures (157 %), intramedullary nailing of pertrochanteric fractures (143 %) and dorsolumbar spinal osteosynthesis (240 %). During external fixation of ankle fractures (68 %) and screw fixation of sacral fractures (66 %) radiation exposure of the theatre nurse exceeded 50 % of the surgeon's radiation exposure. During plate osteosynthesis of distal radius fractures (157 %) and intramedullary splinting of clavicular fractures (115 %), the anaesthesiologist received a higher radiation exposure than the surgeon. The novel dosimeter system DA provides real-time radiation exposure feedback of the personnel in an orthopaedic and trauma operation theatre for the first time. Data of this study demonstrate that radiation exposure of the personnel depends on the operation type. The first assistant, the theatre nurse and the anaesthesiologist might be exposed to higher radiation doses than the surgeon. DA might help to increase awareness concerning irradiation in an orthopaedic and trauma operation theatre and might enhance staff compliance in using radiation protection techniques. Georg Thieme Verlag KG Stuttgart · New York.

ISS External Contamination Environment for Space Science Utilization

NASA Technical Reports Server (NTRS)

Soares, Carlos; Mikatarian, Ron; Steagall, Courtney; Huang, Alvin; Koontz, Steven; Worthy, Erica

2014-01-01

(1) The International Space Station is the largest and most complex on-orbit platform for space science utilization in low Earth orbit, (2) Multiple sites for external payloads, with exposure to the associated natural and induced environments, are available to support a variety of space science utilization objectives, (3) Contamination is one of the induced environments that can impact performance, mission success and science utilization on the vehicle, and (4)The ISS has been designed, built and integrated with strict contamination requirements to provide low levels of induced contamination on external payload assets.

External Contamination Environment at ISS Included: Selected Results from Payloads Contamination Mapping Delivery 3 Package

NASA Technical Reports Server (NTRS)

Olsen, Randy; Huang, Alvin; Steagall, Courtney; Kohl, Nathaniel; Koontz, Steve; Worthy, Erica

2017-01-01

The International Space Station is the largest and most complex on-orbit platform for space science utilization in low Earth orbit. Multiple sites for external payloads, with exposure to the associated natural and induced environments, are available to support a variety of space science utilization objectives. Contamination is one of the induced environments that can impact performance, mission success and science utilization on the vehicle. The ISS has been designed, built and integrated with strict contamination requirements to provide low levels of induced contamination on external payload assets.

Strain engineering of graphene nanoribbons: pseudomagnetic versus external magnetic fields

NASA Astrophysics Data System (ADS)

Prabhakar, Sanjay; Melnik, Roderick; Bonilla, Luis

2017-05-01

Bandgap opening due to strain engineering is a key architect for making graphene's optoelectronic, straintronic, and spintronic devices. We study the bandgap opening due to strain induced ripple waves and investigate the interplay between pseudomagnetic fields and externally applied magnetic fields on the band structures and spin relaxation in graphene nanoribbons (GNRs). We show that electron-hole bands of GNRs are highly influenced (i.e. level crossing of the bands are possible) by coupling two combined effects: pseudomagnetic fields (PMF) originating from strain tensor and external magnetic fields. In particular, we show that the tuning of the spin-splitting band extends to large externally applied magnetic fields with increasing values of pseudomagnetic fields. Level crossings of the bands in strained GNRs can also be observed due to the interplay between pseudomagnetic fields and externally applied magnetic fields. We also investigate the influence of this interplay on the electromagnetic field mediated spin relaxation mechanism in GNRs. In particular, we show that the spin hot spot can be observed at approximately B = 65 T (the externally applied magnetic field) and B0 = 53 T (the magnitude of induced pseudomagnetic field due to ripple waves) which may not be considered as an ideal location for the design of straintronic devices. Our analysis might be used for tuning the bandgaps in strained GNRs and utilized to design the optoelectronic devices for straintronic applications.

Effects of externally rated job demand and control on depression diagnosis claims in an industrial cohort.

PubMed

DeSanto Iennaco, Joanne; Cullen, Mark R; Cantley, Linda; Slade, Martin D; Fiellin, Martha; Kasl, Stanislav V

2010-02-01

This study examined whether externally rated job demand and control were associated with depression diagnosis claims in a heavy industrial cohort. The retrospective cohort sample consisted of 7,566 hourly workers aged 18-64 years who were actively employed at 11 US plants between January 1, 1996, and December 31, 2003, and free of depression diagnosis claims during an initial 2-year run-in period. Logistic regression analysis was used to model the effect of tertiles of demand and control exposure on depression diagnosis claims. Demand had a significant positive association with depression diagnosis claims in bivariate models and models adjusted for demographic (age, gender, race, education, job grade, tenure) and lifestyle (smoking status, body mass index, cholesterol level) variables (high demand odds ratio = 1.39, 95% confidence interval: 1.04, 1.86). Control was associated with greater risk of depression diagnosis at moderate levels in unadjusted models only (odds ratio = 1.47, 95% confidence interval: 1.12, 1.93), while low control, contrary to expectation, was not associated with depression. The effects of the externally rated demand exposure were lost with adjustment for location. This may reflect differences in measurement or classification of exposure, differences in depression diagnosis by location, or other location-specific factors.

Effects of Externally Rated Job Demand and Control on Depression Diagnosis Claims in an Industrial Cohort

PubMed Central

DeSanto Iennaco, Joanne; Cullen, Mark R.; Cantley, Linda; Slade, Martin D.; Fiellin, Martha; Kasl, Stanislav V.

2010-01-01

This study examined whether externally rated job demand and control were associated with depression diagnosis claims in a heavy industrial cohort. The retrospective cohort sample consisted of 7,566 hourly workers aged 18–64 years who were actively employed at 11 US plants between January 1, 1996, and December 31, 2003, and free of depression diagnosis claims during an initial 2-year run-in period. Logistic regression analysis was used to model the effect of tertiles of demand and control exposure on depression diagnosis claims. Demand had a significant positive association with depression diagnosis claims in bivariate models and models adjusted for demographic (age, gender, race, education, job grade, tenure) and lifestyle (smoking status, body mass index, cholesterol level) variables (high demand odds ratio = 1.39, 95% confidence interval: 1.04, 1.86). Control was associated with greater risk of depression diagnosis at moderate levels in unadjusted models only (odds ratio = 1.47, 95% confidence interval: 1.12, 1.93), while low control, contrary to expectation, was not associated with depression. The effects of the externally rated demand exposure were lost with adjustment for location. This may reflect differences in measurement or classification of exposure, differences in depression diagnosis by location, or other location-specific factors. PMID:20035011

Children's Exposure to Violence: The Underlying Effect of Posttraumatic Stress Symptoms on Behavior Problems.

PubMed

Yoon, Susan; Steigerwald, Stacey; Holmes, Megan R; Perzynski, Adam T

2016-02-01

In this study we investigated whether witnessing violence and violence victimization were associated with children's internalizing and externalizing behavior problems and examined the mediating role of posttraumatic stress (PTS) symptoms in these relationships. Secondary data analysis was conducted using 3 waves of data from the National Survey of Child and Adolescent Well-Being. Path analyses were conducted to test direct and indirect effects of violence exposure on behavior problems, using 2,064 children (ages 8-15 years) reported to Child Protective Services for maltreatment. Being a victim of violence in the home was directly associated with more internalizing (β = .06, p = .007) and externalizing behavior problems (β = .07, p = .002), whereas witnessing violence was not directly related to either internalizing (β = .04, p = .056) or externalizing behavior problems (β = .03, p = .130). PTS symptoms mediated the effects of witnessing violence and violence victimization on internalizing behavior problems (β = .02, p = .002). Our findings suggest that PTS symptoms may be a mechanism underlying the association between violence exposure and internalizing behavior problems (R(2) = .23), underscoring the potential importance of assessing PTS symptoms and providing targeted trauma-focused interventions for children exposed to violence at home. Copyright © 2016 International Society for Traumatic Stress Studies.

External Exposure to Short- and Medium-Chain Chlorinated Paraffins for the General Population in Beijing, China.

PubMed

Gao, Wei; Cao, Dandan; Wang, Yingjun; Wu, Jing; Wang, Ying; Wang, Yawei; Jiang, Guibin

2018-01-02

Chlorinated paraffins (CPs) are a class of compounds that are currently produced and used in large amounts in commercial products worldwide. In this study, food, indoor air, indoor dust, and drinking water samples were collected to evaluate the external exposure levels of CPs and possible pathway for the general population in Beijing, China. Short chain CPs (SCCPs) and medium chain CPs (MCCPs) in 199 samples were analyzed using a gas chromatography tandem time-of-flight high-resolution mass spectrometry (GC-TOF-HR-MS) method. High levels of CPs were observed in the indoor environment from residential houses, offices, and student dormitories. The geometric mean concentrations (GM) of ∑SCCPs and ∑MCCPs in indoor dust were 92 μg g -1 and 82 μg g -1 , respectively, while in indoor air, the concentrations were 80 ng m -3 and 3.4 ng m -3 , respectively. The GM of ∑SCCPs and ∑MCCPs in the diet were 83 ng g -1 dry weight (dw) and 56 ng g -1 dw, respectively. The most important external exposure routes to CPs to the general populations in Beijing were food intake and indoor dust ingestion. Indoor dust and indoor air posed higher risks for toddlers and infants than for adults.

The Costs and Benefits of Active Coping for Adolescents Residing in Urban Poverty.

PubMed

Carothers, Kristin J; Arizaga, Jessica A; Carter, Jocelyn Smith; Taylor, Jeremy; Grant, Kathryn E

2016-07-01

The present study addresses the lack of specificity and diversity highlighted in recent stress literature reviews by examining active coping in relationships between exposure to violence and internalizing and externalizing symptoms in a sample of urban youth from predominantly low-income, African American and Latino backgrounds. Two hundred and forty-one youth (mean age at Time 1 = 13 years; 66 % female; 41 % African American, 28 % Latino, 14 % European American, 6 % Asian American, 7 % mixed/biracial, 1 % American Indian/native American, .5 % Hawaiian/Pacific Islander, 2 % other) and their parents participated in this three-wave study. Hierarchical regression analyses tested for moderation, and a cross lag panel path analysis tested for mediation. The results provide greater support for active coping as a variable that changes the relationship between exposure to community violence and externalizing symptoms, or moderation, rather than one that explains or mediates it. Further, specificity did not emerge for type of psychological outcome but did emerge for gender, such that active coping exacerbated the association between exposure to community violence and both internalizing and externalizing symptoms for girls, but not boys. These findings highlight the importance of contextual and demographic factors in influencing stress and coping processes during adolescence.

Estimated dose rates to members of the public from external exposure to patients with 131I thyroid treatment

DOE PAGES

Dewji, S.; Bellamy, M.; Hertel, N.; ...

2015-03-25

The purpose of this study is to estimate dose rates that may result from exposure to patients who had been administered iodine-131 ( 131I) as part of medical therapy were calculated. These effective dose rate estimates were compared with simplified assumptions under United States Nuclear Regulatory Commission Regulatory Guide 8.39, which does not consider body tissue attenuation nor time-dependent redistribution and excretion of the administered 131I. Methods: Dose rates were estimated for members of the public potentially exposed to external irradiation from patients recently treated with 131I. Tissue attenuation and iodine biokinetics were considered in the patient in a largermore » comprehensive effort to improve external dose rate estimates. The external dose rate estimates are based on Monte Carlo simulations using the Phantom with Movable Arms and Legs (PIMAL), previously developed by Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission. PIMAL was employed to model the relative positions of the 131I patient and members of the public in three exposure scenarios: (1) traveling on a bus in a total of six seated or standing permutations, (2) two nursing home cases where a caregiver is seated at 30 cm from the patient’s bedside and a nursing home resident seated 250 cm away from the patient in an adjacent bed, and (3) two hotel cases where the patient and a guest are in adjacent rooms with beds on opposite sides of the common wall, with the patient and guest both in bed and either seated back-to-back or lying head to head. The biokinetic model predictions of the retention and distribution of 131I in the patient assumed a single voiding of urinary bladder contents that occurred during the trip at 2, 4, or 8 h after 131I administration for the public transportation cases, continuous first-order voiding for the nursing home cases, and regular periodic voiding at 4, 8, or 12 h after administration for the hotel room cases. Organ specific activities of 131I in the thyroid, bladder, and combined remaining tissues were calculated as a function of time after administration. Exposures to members of the public were considered for 131I patients with normal thyroid uptake (peak thyroid uptake of ~27% of administered 131I), differentiated thyroid cancer (DTC, 5% uptake), and hyperthyroidism (80% uptake). Results: The scenario with the patient seated behind the member of the public yielded the highest dose rate estimate of seated public transportation exposure cases. The dose rate to the adjacent room guest was highest for the exposure scenario in which the hotel guest and patient are seated by a factor of ~4 for the normal and differentiated thyroid cancer uptake cases and by a factor of ~3 for the hyperthyroid case. Conclusions: It was determined that for all modeled cases, the DTC case yielded the lowest external dose rates, whereas the hyperthyroid case yielded the highest dose rates. In estimating external dose to members of the public from patients with 131I therapy, consideration must be given to (patient- and case-specific) administered 131I activities and duration of exposure for a more complete estimate. The method implemented here included a detailed calculation model, which provides a means to determine dose rate estimates for a range of scenarios. Finally, the method was demonstrated for variations of three scenarios, showing how dose rates are expected to vary with uptake, voiding pattern, and patient location.« less

Estimated dose rates to members of the public from external exposure to patients with 131I thyroid treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dewji, S.; Bellamy, M.; Hertel, N.

The purpose of this study is to estimate dose rates that may result from exposure to patients who had been administered iodine-131 ( 131I) as part of medical therapy were calculated. These effective dose rate estimates were compared with simplified assumptions under United States Nuclear Regulatory Commission Regulatory Guide 8.39, which does not consider body tissue attenuation nor time-dependent redistribution and excretion of the administered 131I. Methods: Dose rates were estimated for members of the public potentially exposed to external irradiation from patients recently treated with 131I. Tissue attenuation and iodine biokinetics were considered in the patient in a largermore » comprehensive effort to improve external dose rate estimates. The external dose rate estimates are based on Monte Carlo simulations using the Phantom with Movable Arms and Legs (PIMAL), previously developed by Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission. PIMAL was employed to model the relative positions of the 131I patient and members of the public in three exposure scenarios: (1) traveling on a bus in a total of six seated or standing permutations, (2) two nursing home cases where a caregiver is seated at 30 cm from the patient’s bedside and a nursing home resident seated 250 cm away from the patient in an adjacent bed, and (3) two hotel cases where the patient and a guest are in adjacent rooms with beds on opposite sides of the common wall, with the patient and guest both in bed and either seated back-to-back or lying head to head. The biokinetic model predictions of the retention and distribution of 131I in the patient assumed a single voiding of urinary bladder contents that occurred during the trip at 2, 4, or 8 h after 131I administration for the public transportation cases, continuous first-order voiding for the nursing home cases, and regular periodic voiding at 4, 8, or 12 h after administration for the hotel room cases. Organ specific activities of 131I in the thyroid, bladder, and combined remaining tissues were calculated as a function of time after administration. Exposures to members of the public were considered for 131I patients with normal thyroid uptake (peak thyroid uptake of ~27% of administered 131I), differentiated thyroid cancer (DTC, 5% uptake), and hyperthyroidism (80% uptake). Results: The scenario with the patient seated behind the member of the public yielded the highest dose rate estimate of seated public transportation exposure cases. The dose rate to the adjacent room guest was highest for the exposure scenario in which the hotel guest and patient are seated by a factor of ~4 for the normal and differentiated thyroid cancer uptake cases and by a factor of ~3 for the hyperthyroid case. Conclusions: It was determined that for all modeled cases, the DTC case yielded the lowest external dose rates, whereas the hyperthyroid case yielded the highest dose rates. In estimating external dose to members of the public from patients with 131I therapy, consideration must be given to (patient- and case-specific) administered 131I activities and duration of exposure for a more complete estimate. The method implemented here included a detailed calculation model, which provides a means to determine dose rate estimates for a range of scenarios. Finally, the method was demonstrated for variations of three scenarios, showing how dose rates are expected to vary with uptake, voiding pattern, and patient location.« less

Changes in post-traumatic symptom pattern during and after exposure to extreme war stress: an uncontrolled, preliminary study supporting the dose-response model.

PubMed

Ben-Ezra, Menachem; Palgi, Yuval; Shrira, Amit; Sternberg, Dina; Essar, Nir

2010-01-01

Exposure to prolonged war stress is understudied. While there is debate regarding the empirical data of the dose-response model for posttraumatic stress disorder (PTSD), little is known about how weekly changes in external stress influences the level of PTSD symptoms. The purpose of this study was to measure the relation between objective external stress and PTSD symptoms across time, and thus, gain a deeper understating of the dose-response model. The study hypothesis postulates that the more severe the external stressor, the more severe the exhibition of traumatic symptoms. Thirteen special army administrative staff (SAAS) members from the Rambam Medical Center in Haifa attended seven intervention meetings during the war. These personnel answered a battery of questionnaires regarding demographics and PTSD symptoms during each session. A non-parametric test was used in order to measure the changes in PTSD symptoms between sessions. Pearson correlations were used in order to study the relationship between the magnitude of external stressors and the severity of PTSD symptoms. The results suggested that there was a significant relationship between the magnitude of external stressors and the severity of PTSD symptoms. These results are in line with the dose-response model. The results suggest that a pattern of decline in PTSD symptoms confirm the dose-response model for PTSD.

Doses from external irradiation to Marshall Islanders from Bikini and Enewetak nuclear weapons tests.

PubMed

Bouville, André; Beck, Harold L; Simon, Steven L

2010-08-01

Annual doses from external irradiation resulting from exposure to fallout from the 65 atmospheric nuclear weapons tests conducted in the Marshall Islands at Bikini and Enewetak between 1946 and 1958 have been estimated for the first time for Marshallese living on all inhabited atolls. All tests that deposited fallout on any of the 23 inhabited atolls or separate reef islands have been considered. The methodology used to estimate the radiation doses at the inhabited atolls is based on test- and location-specific radiation survey data, deposition density estimates of 137Cs, and fallout times-of-arrival provided in a companion paper (Beck et al.), combined with information on the radionuclide composition of the fallout at various times after each test. These estimates of doses from external irradiation have been combined with corresponding estimates of doses from internal irradiation, given in a companion paper (Simon et al.), to assess the cancer risks among the Marshallese population (Land et al.) resulting from exposure to radiation from the nuclear weapons tests.

Temperament Moderates Associations Between Exposure to Stress and Children’s Externalizing Problems

PubMed Central

Schermerhorn, Alice C.; Bates, John E.; Goodnight, Jackson A.; Lansford, Jennifer E.; Dodge, Kenneth A.; Pettit, Gregory S.

2013-01-01

The interaction between a temperament profile (four groups determined by high vs. low resistance to control [unmanageability] and unadaptability [novelty distress]) and family stress in predicting externalizing problems at school in children followed from kindergarten through 8th grade (ages 5 – 13) was investigated. The sample consisted of 556 families (290 boys). At Time 1 just prior to kindergarten, mothers retrospectively reported on their child’s temperament during infancy. Each year, mothers reported stress and teachers reported children’s externalizing problems. Temperament profile was tested as a moderator of the stress-externalizing association for various time periods. Results indicated that the combination of high resistance to control and high unadaptability strengthens the stress-externalizing association. Findings are discussed in terms of possible underlying mechanisms. PMID:23438634

Comorbidity in illness-induced posttraumatic stress disorder versus posttraumatic stress disorder due to external events in a nationally representative study.

PubMed

Sommer, Jordana L; Mota, Natalie; Edmondson, Donald; El-Gabalawy, Renée

2018-05-10

The current study compared physical and mental health characteristics and quality of life of illness-induced posttraumatic stress disorder (PTSD) versus those with PTSD due to external traumatic events in a population-based sample. PTSD was assessed with the Alcohol Use Disorder and Associated Disabilities Interview Schedule (AUDADIS-5) using DSM-5 criteria in the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions. Participants with past-year PTSD (n = 1779) were categorized into two groups: illness-induced (6.5%) and other trauma-induced PTSD (92.9%) based on index trauma. Group differences in physical health, mental health, and quality of life were estimated using multiple logistic and linear regressions with adjustment for demographics and medical morbidity. Compared to PTSD due to external events, illness-induced PTSD had higher rates of life-threatening illness in the past year. Illness-induced PTSD compared to PTSD due to external events was associated with reduced odds of depressive/bipolar disorders and antisocial personality disorder, but increased odds of cannabis use disorder. The groups did not differ on quality of life after accounting for medical morbidity. Illness-induced PTSD is common among American adults and has a similar impact on quality of life as PTSD due to external events, but may have distinct mental health correlates. Copyright © 2018 Elsevier Inc. All rights reserved.

The leading role of mitochondrial depolarization in the mechanism of glutamate-induced disruptions in Ca2+ homeostasis.

PubMed

Khodorov, B I; Storozhevykh, T P; Surin, A M; Yuryavichyus, A I; Sorokina, E G; Borodin, A V; Vinskaya, N P; Khaspekov, L G; Pinelis, V G

2002-01-01

Data obtained in studies of the nature of the correlation which we have previously observed [10,17] between mitochondrial depolarization and the level of disruption of Ca2+ homeostasis in cultivated brain neuronsare summarized. Experiments were performed on cultured cerebellar granule cells loaded with Fura-2-AM or rhodamine 123 to measure changes in cytoplasmic Ca2+ and mitochondrial potential during pathogenic treatments of the cells. Prolonged exposure to 100 microM glutamate induced a reversible increase in [Ca2+]i, which was accompanied by only a small degree of mitochondrial depolarization. A sharp increase in this mitochondrial depolarization, induced by addition of 3 mM NaCN or 300 microM dinitrophenol (DNP) to the glutamate-containing solution, resulted in further increase in [Ca2+]i, due to blockade of electrophoretic mitochondrial Ca2+ uptake. Prolonged exposure to CN- or DNP in the post-glutamate period maintained [Ca2+]i at a high level until the metabolic inhibitors were removed. In most cells, this plateau was characterized by low sensitivity to removal of external Ca2+, demonstrating that the mechanisms of Ca2+ release from neurons were disrupted. Addition of oligomycin, a blocker of mitochondrial ATP synthase/ATPase, to the solution containing glutamate and CN- or DNP eliminated the post-glutamate plateau. Parallel experiments with direct measurements of intracellular ATP levels ([ATP]) showed that profound mitochondrial depolarization induced by CN- or DNP sharply enhanced the drop in ATP due to glutamate, while oligomycin significantly weakened this effect of the metabolic inhibitors. Analysis of these data led to the conclusion that blockade of mitochondrial Ca2+ uptake and inhibition of ATP synthesis resulted from mitochondrial depolarization and plays a key role in the mechanism disrupting [Ca2+]i homeostasis after toxic exposure to glutamate.

Induced Mitogenic Activity in AML-12 Mouse Hepatocytes Exposed to Low-dose Ultra-Wideband Electromagnetic Radiation

PubMed Central

Dorsey, W. C.; Ford, B. D.; Roane, L.; Haynie, D. T.; Tchounwou, P. B.

2005-01-01

Ultra–wideband (UWB) technology has increased with the use of various civilian and military applications. In the present study, we hypothesized that low-dose UWB electromagnetic radiation (UWBR) could elicit a mitogenic effect in AML-12 mouse hepatocytes, in vitro. To test this hypothesis, we exposed AML-12 mouse hepatocytes, to UWBR in a specially constructed gigahertz transverse electromagnetic mode (GTEM) cell. Cells were exposed to UWBR for 2 h at a temperature of 23°C, a pulse width of 10 ns, a repetition rate of 1 kHz, and field strength of 5–20 kV/m. UWB pulses were triggered by an external pulse generator for UWBR exposure but were not triggered for the sham exposure. We performed an MTT Assay to assess cell viability for UWBR-treated and sham-exposed hepatocytes. Data from viability studies indicated a time-related increase in hepatocytes at time intervals from 8–24 h post exposure. UWBR exerted a statistically significant (p < 0.05) dose-dependent response in cell viability in both serum-treated and serum free medium (SFM) -treated hepatocytes. Western blot analysis of hepatocyte lysates demonstrated that cyclin A protein was induced in hepatocytes, suggesting that increased MTT activity after UWBR exposure was due to cell proliferation. This study indicates that UWBR has a mitogenic effect on AML-12 mouse hepatocytes and implicates a possible role for UWBR in hepatocarcinoma. PMID:16705798

Oxidative stress due to aluminum exposure induces eryptosis which is prevented by erythropoietin.

PubMed

Vota, Daiana M; Crisp, Renée L; Nesse, Alcira B; Vittori, Daniela C

2012-05-01

The widespread use of aluminum (Al) provides easy exposure of humans to the metal and its accumulation remains a potential problem. In vivo and in vitro assays have associated Al overload with anemia. To better understand the mechanisms by which Al affects human erythrocytes, morphological and biochemical changes were analyzed after long-term treatment using an in vitro model. The appearance of erythrocytes with abnormal shapes suggested metal interaction with cell surface, supported by the fact that high amounts of Al attached to cell membrane. Long-term incubation of human erythrocytes with Al induced signs of premature erythrocyte death (eryptosis), such as phosphatidylserine externalization, increased intracellular calcium, and band 3 degradation. Signs of oxidative stress, such as significant increase in reactive oxygen species in parallel with decrease in the amount of reduced glutathione, were also observed. These oxidative effects were completely prevented by the antioxidant N-acetylcysteine. Interestingly, erythrocytes were also protected from the prooxidative action of Al by the presence of erythropoietin (EPO). In conclusion, results provide evidence that chronic Al exposure may lead to biochemical and morphological alterations similar to those shown in eryptosis induced by oxidant compounds in human erythrocytes. The antieryptotic effect of EPO may contribute to enhance the knowledge of its physiological role on erythroid cells. Irrespective of the antioxidant mechanism, this property of EPO, shown in this model of Al exposure, let us suggest potential benefits by EPO treatment of patients with anemia associated to altered redox environment. Copyright © 2011 Wiley Periodicals, Inc.

Recent GPS Results at SLAC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behrend, Dirk; Imfeld, Hans L.; /SLAC

2005-08-17

The Alignment Engineering Group (AEG) makes use of GPS technology for fulfilling part of its above ground surveying tasks at SLAC since early 2002. A base station (SLAC M40) has been set up at a central location of the SLAC campus serving both as master station for real-time kinematic (RTK) operations and as datum point for local GPS campaigns. The Leica RS500 system is running continuously and the GPS data are collected both externally (logging PC) and internally (receiver flashcard). The external logging is facilitated by a serial to Ethernet converter and an Ethernet connection at the station. Internal loggingmore » (ring buffer) is done for data security purposes. The weatherproof boxes for the instrumentation are excellent shelters against rain and wind, but do heat up considerably in sun light. Whereas the GPS receiver showed no problems, the Pacific Crest PDL 35 radio shut down several times due to overheating disrupting the RTK operations. In order to prevent heat-induced shutdowns, a protection against direct sun exposure (shading) and a constant air circulation system (ventilation) were installed. As no further shutdowns have occurred so far, it appears that the two measures successfully mended the heat problem.« less

Refining and validating a two-stage and web-based cancer risk assessment tool for village doctors in China.

PubMed

Shen, Xing-Rong; Chai, Jing; Feng, Rui; Liu, Tong-Zhu; Tong, Gui-Xian; Cheng, Jing; Li, Kai-Chun; Xie, Shao-Yu; Shi, Yong; Wang, De-Bin

2014-01-01

The big gap between efficacy of population level prevention and expectations due to heterogeneity and complexity of cancer etiologic factors calls for selective yet personalized interventions based on effective risk assessment. This paper documents our research protocol aimed at refining and validating a two-stage and web- based cancer risk assessment tool, from a tentative one in use by an ongoing project, capable of identifying individuals at elevated risk for one or more types of the 80% leading cancers in rural China with adequate sensitivity and specificity and featuring low cost, easy application and cultural and technical sensitivity for farmers and village doctors. The protocol adopted a modified population-based case control design using 72, 000 non-patients as controls, 2, 200 cancer patients as cases, and another 600 patients as cases for external validation. Factors taken into account comprised 8 domains including diet and nutrition, risk behaviors, family history, precancerous diseases, related medical procedures, exposure to environment hazards, mood and feelings, physical activities and anthropologic and biologic factors. Modeling stresses explored various methodologies like empirical analysis, logistic regression, neuro-network analysis, decision theory and both internal and external validation using concordance statistics, predictive values, etc..

Electrically induced formation of uncapped, hollow polymeric microstructures

NASA Astrophysics Data System (ADS)

Lee, Sung Hun; Kim, Pilnam; Jeong, Hoon Eui; Suh, Kahp Y.

2006-11-01

Uncapped, hollow polymeric microstructures were fabricated on a silicon substrate using electric field induced stretching and detachment. Initially, square or cylinder microposts were generated using a solvent-assisted capillary molding technique, and a featureless electrode mask was positioned on the top of the microstructure with spacers maintaining an air gap (~20 µm). Upon exposure to an external electric field (1.0-3.0 V µm-1), the hollow microstructures were destabilized and stretched by the well-known electrohydrodynamic instability, resulting in contact of the top polymer surface with the mask. Subsequently, detachment of the capping layer occurred upon removal of the mask due to larger adhesion forces at the polymer/mask interface than cohesion forces of the polymer. These hollow microstructures were tested to capture the budding yeast, Saccharomyces cerevisiae, for shear protection.

Magnetomechanical effect in silicon (Cz-Si) surface layers

NASA Astrophysics Data System (ADS)

Koplak, O. V.; Dmitriev, A. I.; Morgunov, R. B.

2012-07-01

The mechanical properties of near-surface layers of Czochralski-grown silicon crystals Cz- n-Si(111) have been found to undergo changes in response to an external constant magnetic field ( B ˜ 0.1 T). A magnetically induced variation in the microhardness, Young's modulus, and coefficient of plasticity of silicon crystals correlates with the change in the lattice parameter and internal stresses of the sample. The growth of an oxide film under exposure to a magnetic field plays the principal role in the magnetomechanical effect due to a decrease in the concentration of oxygen complexes in the near-surface layers of the sample. In microstructured silicon, where the surface is considerably more developed, the magnetic field induces more profound changes in the internal stresses as compared to single crystals.

The Philosophy, Theoretical Bases, and Implementation of the AHAAH Model for Evaluation of Hazard from Exposure to Intense Sounds

DTIC Science & Technology

2018-04-01

empirical, external energy-damage correlation methods for evaluating hearing damage risk associated with impulsive noise exposure. AHAAH applies the...is validated against the measured results of human exposures to impulsive sounds, and unlike wholly empirical correlation approaches, AHAAH’s...a measured level (LAEQ8 of 85 dB). The approach in MIL-STD-1474E is very different. Previous standards tried to find a correlation between some

Thyroid Cancer after Childhood Exposure to External Radiation: An Updated Pooled Analysis of 12 Studies.

PubMed

Veiga, Lene H S; Holmberg, Erik; Anderson, Harald; Pottern, Linda; Sadetzki, Siegal; Adams, M Jacob; Sakata, Ritsu; Schneider, Arthur B; Inskip, Peter; Bhatti, Parveen; Johansson, Robert; Neta, Gila; Shore, Roy; de Vathaire, Florent; Damber, Lena; Kleinerman, Ruth; Hawkins, Michael M; Tucker, Margaret; Lundell, Marie; Lubin, Jay H

2016-05-01

Studies have causally linked external thyroid radiation exposure in childhood with thyroid cancer. In 1995, investigators conducted relative risk analyses of pooled data from seven epidemiologic studies. Doses were mostly <10 Gy, although childhood cancer therapies can result in thyroid doses >50 Gy. We pooled data from 12 studies of thyroid cancer patients who were exposed to radiation in childhood (ages <20 years), more than doubling the data, including 1,070 (927 exposed) thyroid cancers and 5.3 million (3.4 million exposed) person-years. Relative risks increased supralinearly through 2-4 Gy, leveled off between 10-30 Gy and declined thereafter, remaining significantly elevated above 50 Gy. There was a significant relative risk trend for doses <0.10 Gy (P < 0.01), with no departure from linearity (P = 0.36). We observed radiogenic effects for both papillary and nonpapillary tumors. Estimates of excess relative risk per Gy (ERR/Gy) were homogeneous by sex (P = 0.35) and number of radiation treatments (P = 0.84) and increased with decreasing age at the time of exposure. The ERR/Gy estimate was significant within ten years of radiation exposure, 2.76 (95% CI, 0.94-4.98), based on 42 exposed cases, and remained elevated 50 years and more after exposure. Finally, exposure to chemotherapy was significantly associated with thyroid cancer, with results supporting a nonsynergistic (additive) association with radiation.

[Cardiovascular risk, occupation and exposure to occupational carcinogens in a group of workers in Salamanca].

PubMed

González-Sánchez, Jesús

2015-01-01

Identify the cardiovascular risk factors in a group of workers in the province of Salamanca, protected by external prevention services, as regards exposure to occupational carcinogens, by sector of activity and gender. An observational descriptive epidemiological study was conducted. The sample selection was by stratified random sampling in each entity. The variables collected by questionnaire were, sociodemographic characteristics, exposure to occupational carcinogens, and cardiovascular risk factors (smoking, hypertension, dyslipidemia, and diabetes), using the clinical-work histories as a source of information. Statistically significant differences were observed in cardiovascular risk according to the exposure to occupational carcinogens (p <0.001), primarily among workers in the industry sector. A total of 32% of the workers in the province of Salamanca was exposed to some occupational carcinogen. Women were more exposed in the service sector and men in the agriculture and livestock sector. Nearly one third of the workers belonging to the external prevention services of the province of Salamanca, were exposed to some kind of occupational carcinogens. The most frequent being biological risks, solvent products, and silica, which were above the national mean of exposure. It is important to consider the exposure to occupational carcinogens in the implementation of interventions in the prevention of cardiovascular risk in the work place. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Analysis of EPR and FISH studies of radiation doses in persons who lived in the upper reaches of the Techa River.

PubMed

Degteva, M O; Shagina, N B; Shishkina, E A; Vozilova, A V; Volchkova, A Y; Vorobiova, M I; Wieser, A; Fattibene, P; Della Monaca, S; Ainsbury, E; Moquet, J; Anspaugh, L R; Napier, B A

2015-11-01

Waterborne radioactive releases into the Techa River from the Mayak Production Association in Russia during 1949-1956 resulted in significant doses to about 30,000 persons who lived in downstream settlements. The residents were exposed to internal and external radiation. Two methods for reconstruction of the external dose are considered in this paper, electron paramagnetic resonance (EPR) measurements of teeth, and fluorescence in situ hybridization (FISH) measurements of chromosome translocations in circulating lymphocytes. The main issue in the application of the EPR and FISH methods for reconstruction of the external dose for the Techa Riverside residents was strontium radioisotopes incorporated in teeth and bones that act as a source of confounding local exposures. In order to estimate and subtract doses from incorporated (89,90)Sr, the EPR and FISH assays were supported by measurements of (90)Sr-body burdens and estimates of (90)Sr concentrations in dental tissues by the luminescence method. The resulting dose estimates derived from EPR to FISH measurements for residents of the upper Techa River were found to be consistent: The mean values vary from 510 to 550 mGy for the villages located close to the site of radioactive release to 130-160 mGy for the more distant villages. The upper bound of individual estimates for both methods is equal to 2.2-2.3 Gy. The EPR- and FISH-based dose estimates were compared with the doses calculated for the donors using the most recent Techa River Dosimetry System (TRDS). The TRDS external dose assessments are based on the data on contamination of the Techa River floodplain, simulation of air kerma above the contaminated soil, age-dependent lifestyles and individual residence histories. For correct comparison, TRDS-based doses were calculated from two sources: external exposure from the contaminated environment and internal exposure from (137)Cs incorporated in donors' soft tissues. It is shown here that the TRDS-based absorbed doses in tooth enamel and muscle are in agreement with EPR- and FISH-based estimates within uncertainty bounds. Basically, this agreement between the estimates has confirmed the validity of external doses calculated with the TRDS.

High-resolution modelling of health impacts and related external cost from air pollution over 36 years using the integrated model system EVA

NASA Astrophysics Data System (ADS)

Brandt, Jørgen; Andersen, Mikael S.; Bønløkke, Jakob; Christensen, Jesper H.; Geels, Camilla; Hansen, Kaj M.; Hertel, Ole; Im, Ulas; Jensen, Steen S.; Ketzel, Matthias; Nielsen, Ole-Kenneth; Plejdrup, Marlene S.; Sigsgaard, Torben

2016-04-01

A high-resolution assessment of health impacts from air pollution and related external cost has been conducted for Denmark using the integrated EVA model system. The EVA system is based on the impact-pathway methodology, where the site-specific emissions will result, via atmospheric transport and chemistry, in a concentration distribution, which together with detailed population data, is used to estimate the population-level exposure. Using exposure-response functions and economic valuations, the exposure is transformed into impacts on human health and related external costs. In this study we have used a coupling of two chemistry transport models to calculate the air pollution concentration at different domain and scales; the Danish Eulerian Hemispheric Model (DEHM) to calculate the air pollution levels in the Northern Hemisphere with a resolution down to 5.6 km x 5.6 km and the Urban Background Model (UBM) to further calculate the air pollution in Denmark at 1 km x 1 km resolution using results from DEHM as boundary conditions. Both the emission data as well as the population density has been represented in the model system with the same high resolution. Previous health impact assessments related to air pollution have been made on a lower resolution. In this study, the integrated model system, EVA, has been used to estimate the health impacts and related external cost for Denmark at a 1 km x 1 km resolution. New developments of the integrated model system will be presented as well as the development of health impacts and related external costs in Europe and Denmark over a period of 36 years (1979-2014). Acknowledgements This work was funded by: DCE - National Centre for Environment and Energy. Project: "Health impacts and external costs from air pollution in Denmark over 25 years" and NordForsk under the Nordic Programme on Health and Welfare. Project: "Understanding the link between air pollution and distribution of related health impacts and welfare in the Nordic countries (NordicWelfAir)".

Elevated manganese exposure and school-aged children's behavior: a gender-stratified analysis.

PubMed

Menezes-Filho, José A; de Carvalho-Vivas, Chrissie F; Viana, Gustavo F S; Ferreira, Junia R D; Nunes, Lorena S; Mergler, Donna; Abreu, Neander

2014-12-01

High levels of waterborne manganese have been associated with problematic behavior in school-aged children, however to date this has not been reported for children exposed to airborne manganese. The objective of the present study was to examine behavioral traits among children with exposure to airborne manganese from a ferro-manganese alloy plant, located in the metropolitan region of Salvador, Brazil. The study included 34 boys and 36 girls, aged 7-12 years, living in two communities within a 3-km radius from the plant. For each child, hair manganese levels (MnH) and blood lead (PbB) levels were analyzed by graphite furnace atomic absorption spectrometry. The Children's Behavior Check List (CBCL) (Portuguese version validated in Brazil) was administered to parents or caregivers, providing scale scores of internalizing (withdrawn, somatic complaints, and anxious/depressed scales), externalizing (disruptive and aggressive) behaviors and a separate scale for attention problems. Median and range for MnH and PbB were 11.48 μg/g (range: 0.52-55.74); 1.1 μg/dL (range: 0.5-6.1), respectively. Spearman correlation analyses showed that several behavioral indices were significantly correlated with MnH levels for girls, but not for boys: total externalizing behavior (rho=0.484 vs rho=0.041) and attention problem scores (rho=0.542 vs rho=0.003) coefficients were significantly at p<0.001 level, respectively for girls and boys. No significant correlation was observed with any of the internalizing sub-scales. A linear regression model was fitted with the total externalizing behavior, inattention and total CBCL scores as dependent variables, with log transformed MnH stratified by sex, adjusting for age and maternal IQ. Total externalizing behaviors and attention problem scores were significantly associated with girls' MnH levels but not with boys'. Adjusting for maternal IQ, the β-coefficients for LogMnH associations with total externalizing and attention problems are 8.85 (95%CI 2.44-15.24) and 4.03 (95%CI 1.50-6.56) for girls. For boys, after adjusting for age, the β-coefficients are 0.08 (95%CI 11.51-11.66) and -0.05 (95%CI 4.34-4.25), respectively. The findings of this study suggest a positive association between elevated Mn exposure and externalizing behavioral problems and inattention, with girls presenting more pronounced effects. Future studies on Mn exposure in children should attempt to further elucidate sex and/or gender differences in Mn exposed populations. Copyright © 2013 Elsevier Inc. All rights reserved.

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

PubMed

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

2017-10-01

Although human biological indicators have been widely utilized for biomonitoring environmental pollutants in health exposure assessment, the relationship between internal and external exposure has not yet been adequately established. In this study, we collected and analyzed 61 rice, 56 pepper, and 58 soil samples, together with 107 hair, 107 blood, and 107 urine samples from residents living in selected intensive mining areas in China. Concentrations of most of the four elements considered (Pb, Cd, Hg, and Se) exceeded national standards, implying high exposure risk in the study areas. Regression analysis also revealed a correlation (0.33, P < 0.001) between the concentration of Pb in soil and that in human hair (as well as in human blood); to some extent, Pb content in hair and blood could therefore be used to characterize external Pb exposure. The correlation between Hg in rice and in human hair (up to 0.5, P < 0.001) further confirmed a significant indicative effect of human hair for Hg exposure. A significant correlation was also noted between concentrations of some elements in different human samples, for example, between Hg in hair and blood (0.641, P < 0.01) and between Cd in urine and blood (0.339, P < 0.01). To some extent, there could thus be mutual reflectance of the same heavy metal in different samples, with the possibility for complementary use in assessing heavy metal exposure.

Protective Factors for Youth Exposed to Violence in Their Communities: A Review of Family, School, and Community Moderators.

PubMed

Ozer, Emily J; Lavi, Iris; Douglas, Laura; Wolf, Jennifer Price

2017-01-01

This review provides a comprehensive investigation of the pattern and strength of findings in the literature regarding the environmental moderators of the relationship between exposure to community violence and mental health among children and adolescents. Twenty-nine studies met criteria for inclusion in our analysis of family, school, and community variables as moderators. Dependent variables included internalizing (e.g., anxiety, depression, posttraumatic stress disorder) and externalizing symptoms (e.g., aggression, substance use). Effect sizes for the interactions of exposure to violence and potential moderators were summarized by their patterns of protective processes. The majority of studies in the literature examined family characteristics as moderators of the exposure to violence-symptom relationship, rather than school- or community-level factors. Our results indicated more consistent patterns for (a) close family relationships and social support for internalizing symptoms and (b) close family relationships for externalizing symptoms. Overall, the most common type of protective pattern was protective-stabilizing, in which youth with higher levels of the environmental attribute demonstrate relative stability in mental health despite exposure to violence. We found no consistent evidence that parental monitoring-a dimension inversely associated with exposure to violence in prior studies-moderated the relationship between exposure to violence and symptoms. The study emphasizes the importance of strengthening family support for young people's exposure to community violence; more research is needed to provide a solid evidence base for the role of school and community-level protective factors for youth exposed to violence.

Work-In-Progress Peer Consult on EPA's Multimedia Exposure Analysis to Inform a Public Health-Based Value for Lead in Drinking Water

EPA Science Inventory

This document is a compilation of responses from four external peer reviewers on EPA's "Multimedia Exposure Analysis to Inform a Public Health-Based Value for Lead in Drinking Water." It was delivered by Versar, Inc. under contract number EP-C-12-045 Task Order 91.

Controlling for Selection Effects in the Relationship between Child Behavior Problems and Exposure to Intimate Partner Violence

ERIC Educational Resources Information Center

Emery, Clifton R.

2011-01-01

This article used the Project on Human Development in Chicago Neighborhoods (PHDCN) data to examine the relationship between exposure to intimate partner violence (IPV) and child behavior problems (externalizing and internalizing), truancy, grade repetition, smoking, drinking, and use of marijuana. Longitudinal data analysis was conducted on 1,816…

Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) and Related Compounds: Science Advisory Board (External Review Draft) (2000)

EPA Science Inventory

Dioxin Reassessment, SAB Review Draft

The U.S. Environmental Protection Agency's (EPA) is progressing toward completion of its comprehensive reassessment of dioxin science entitled, "Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibe...