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Sample records for estimating cardiac exposure

  1. Estimating Cardiac Exposure From Breast Cancer Radiotherapy in Clinical Practice

    International Nuclear Information System (INIS)

    Taylor, C.W.; McGale, P.; Povall, J.M.; Thomas, E.; Kumar, S.; Dodwell, D.; Darby, S.C.

    2009-01-01

    Purpose: To assess the value of maximum heart distance (MHD) in predicting the dose and biologically effective dose (BED) to the heart and the left anterior descending (LAD) coronary artery for left-tangential breast or chest wall irradiation. Methods and Materials: A total of 50 consecutive breast cancer patients given adjuvant left-tangential irradiation at a large U.K. radiotherapy center during 2006 were selected. For each patient, the following were derived using three-dimensional computed tomography (CT) planning: (1) mean dose and BED to the heart, (2) mean dose and BED to the LAD coronary artery, (3) MHD, (4) position of the CT slice showing the maximum area of the irradiated heart relative to the mid-plane slice, and (5) sternal and contralateral breast thickness (measures of body fat). Results: A strong linear correlation was found between the MHD and the mean heart dose. For every 1-cm increase in MHD, the mean heart dose increased by 2.9% on average (95% confidence interval 2.5-3.3). A strong linear-quadratic relationship was seen between the MHD and the mean heart BED. The mean LAD coronary artery dose and BED were also correlated with the MHD but the associations were weaker. These relationships were not affected by body fat. The mid-plane CT slice did not give a reliable assessment of cardiac irradiation. Conclusion: The MHD is a reliable predictor of the mean heart dose and BED and gives an approximate estimate of the mean LAD coronary artery dose and BED. Doses predicted by the MHD could help assess the risk of radiation-induced cardiac toxicity where individual CT-based cardiac dosimetry is not possible

  2. Radiation exposure of children during cardiac catheterisation

    International Nuclear Information System (INIS)

    Popp, W.

    1979-01-01

    It is well known that in adults, cardiac catheterisation involves the highest possible radiation exposure for a single examination. The paper now investigates the radiation exposure in paediatric cardiac cathetrisations. Dosimeters attached to the children during the examination were used as well as phantom measurements under the conditions of cardiac catheterisation. With the aid of the phantom, also the total energy absorption during an examination procedure was determined. This value was estimated to be 80 mJ. In spite of the high individual exposure, the contribution to the population exposure is low due to the small number of cardiac catheterisations. (orig.) 891 AJ/orig. 892 MKO [de

  3. Immediate changes in estimated cardiac output and vascular resistance after 60Co exposure in monkeys: implication for performance decrement

    International Nuclear Information System (INIS)

    Bruner, A.

    1977-01-01

    Aortic blood flow velocity, blood pressure, and heart rate were recorded in 12 unanesthetized, nonperforming monkeys during exposure to 1000 rad 60 Co at 129--164 rad/min. The first postradiation changes were seen within 3--4 min of the exposure's start and included tachycardia, a transient hypotension secondary to a loss in peripheral resistance, and a brief increase followed by a decrease to subnormal levels in cardiac output. The lowest cardiac output occurred between 10 and 20 min postexposure while blood pressure and peripheral resistance were recovering. It was proposed that the concurrent combination of low cardiac output, low blood pressure, and supranormal peripheral resistance might sufficiently attenuate cerebral perfusion temporarily to account for the transient behavioral decrements often seen during this time. Histamine release was postulated as responsible for this vascular shock syndrome

  4. Evaluation of the individual tube current setting in electrocardiogram-gated cardiac computed tomography estimated from plain chest computed tomography using computed tomography automatic exposure control

    International Nuclear Information System (INIS)

    Kishimoto, Junichi; Sakou, Toshio; Ohta, Yasutoshi

    2013-01-01

    The aim of this study was to estimate the tube current on a cardiac computed tomography (CT) from a plain chest CT using CT-automatic exposure control (CT-AEC), to obtain consistent image noise, and to optimize the scan tube current by individualizing the tube current. Sixty-five patients (Group A) underwent cardiac CT at fixed tube current. The mAs value for plain chest CT using CT-AEC (AEC value) and cardiac CT image noise were measured. The tube current needed to obtain the intended level of image noise in the cardiac CT was determined from their correlation. Another 65 patients (Group B) underwent cardiac CT with tube currents individually determined from the AEC value. Image noise was compared among Group A and B. Image noise of cardiac CT in Group B was 24.4±3.1 Hounsfield unit (HU) and was more uniform than in Group A (21.2±6.1 HU). The error with the desired image noise of 25 HU was lower in Group B (2.4%) than in Group A (15.2%). Individualized tube current selection based on AEC value thus provided consistent image noise and a scan tube current optimized for cardiac CT. (author)

  5. Radiation exposure during cardiac catheterization procedures

    International Nuclear Information System (INIS)

    Kicken, P.J.H.; Huyskens, C.J.; Michels, H.R.

    1988-01-01

    For some time there has been an increased interest in more information about radiation exposure during cardiac catheterization because of: relatively high doses to workers and patient; rapid increase of numbers of examinations; introduction of new procedure-types (e.g. Percutaneous Transluminal Coronary Angiography, PTCA) and introduction of new techniques (e.g. Digital Subtraction Angiography, DSA). This paper reports about a study on the exposure to medical personnel and patient in two major hospitals in the Netherlands. The Total number of cardiac catheterization procedures in both hospitals amounts to circa 3000 per year (approximately 10% of all cardiac procedures c.q. 20% of all PTCA procedures in the Netherlands). This study is related to 1300 cardiac examinations

  6. Conditional shape models for cardiac motion estimation

    DEFF Research Database (Denmark)

    Metz, Coert; Baka, Nora; Kirisli, Hortense

    2010-01-01

    We propose a conditional statistical shape model to predict patient specific cardiac motion from the 3D end-diastolic CTA scan. The model is built from 4D CTA sequences by combining atlas based segmentation and 4D registration. Cardiac motion estimation is, for example, relevant in the dynamic...

  7. Patient radiation exposure during pediatric cardiac catheterization

    International Nuclear Information System (INIS)

    Fellows, K.E.; Leibovic, S.J.

    1983-01-01

    Exposure air product (EAP) and center field entrance exposure (free-in-air) were measured in seventeen pediatric patients undergoing cardiac catheterization. Exposures were recorded separately for biplane fluoroscopy and cine angiocardiography using flat-plate ionization chambers. In the posterior-anterior (PA) projections, median EAP was 425 Roentgen-square centimeter (R-cm 2 ), with a range of 90.5-3,882 R-cm 2 ; 29-35% of this exposure occurred during cine filming. In the lateral projection, median EAP was 276 R-cm 2 (range 117-1,173); 52-59% of this exposure was due to cine filming. Median center field entrance exposure in the PA view was 7.86 Roentgens (R) with a range 2.16-73.9 of and in the lateral projection 7.39 R (range 2.64-24.6). As much as 25% of the exposure from the entire examination was contributed by manual ''test'' exposures to set cine radiographic kVp. We recommend use of testing circuits, which determine cine radiographic factors automatically and thus should lower levels of exposure

  8. Patient radiation exposure during pediatric cardiac catheterization

    International Nuclear Information System (INIS)

    Fellows, K.E.; Leibovic, S.J.

    1983-01-01

    Exposure are product (EAP) and center field entrance exposure (free-in-air) were measured in seventeen pediatric patients undergoing cardiac catheterization. Exposures were recorded separately for biplane fluoroscopy and cine angiocardiography using flat-plate ionization chambers. In the posterior-anterior (PA) projections, median EAP was 425 Roentgen-square centimeter (R-cm 2 ), with a range of 90.5-3,882 R-cm 2 ; 29-35% of this exposure occurred during cine filming. In the lateral projection, median EAP was 276 R-cm 2 (range 117-1,173); 52-59% of this exposure was due to cine filming. Median center field entrance exposure in the PA view was 7.86 Roentgens (R) with a range 2.16-73.9 of and in the lateral projection 7.39 R (range 2.64-24.6). As much as 25% of the exposure from the entire examination was contributed by manual ''test'' exposures to set cine radiographic kVp. We recommend use of testing circuits, which determine cine radiographic factors automatically and thus should lower levels of exposure. (orig.)

  9. Intramyocardial strain estimation from cardiac cine MRI.

    Science.gov (United States)

    Elnakib, Ahmed; Beache, Garth M; Gimel'farb, Georgy; El-Baz, Ayman

    2015-08-01

    Functional strain is one of the important clinical indicators for the quantification of heart performance and the early detection of cardiovascular diseases, and functional strain parameters are used to aid therapeutic decisions and follow-up evaluations after cardiac surgery. A comprehensive framework for deriving functional strain parameters at the endocardium, epicardium, and mid-wall of the left ventricle (LV) from conventional cine MRI data was developed and tested. Cine data were collected using short TR-/TE-balanced steady-state free precession acquisitions on a 1.5T Siemens Espree scanner. The LV wall borders are segmented using a level set-based deformable model guided by a stochastic force derived from a second-order Markov-Gibbs random field model that accounts for the object shape and appearance features. Then, the mid-wall of the segmented LV is determined based on estimating the centerline between the endocardium and epicardium of the LV. Finally, a geometrical Laplace-based method is proposed to track corresponding points on successive myocardial contours throughout the cardiac cycle in order to characterize the strain evolutions. The method was tested using simulated phantom images with predefined point locations of the LV wall throughout the cardiac cycle. The method was tested on 30 in vivo datasets to evaluate the feasibility of the proposed framework to index functional strain parameters. The cine MRI-based model agreed with the ground truth for functional metrics to within 0.30 % for indexing the peak systolic strain change and 0.29 % (per unit time) for indexing systolic and diastolic strain rates. The method was feasible for in vivo extraction of functional strain parameters. Strain indexes of the endocardium, mid-wall, and epicardium can be derived from routine cine images using automated techniques, thereby improving the utility of cine MRI data for characterization of myocardial function. Unlike traditional texture-based tracking, the

  10. Radiation Dose Estimation for Pediatric Patients Undergoing Cardiac Catheterization

    Science.gov (United States)

    Wang, Chu

    Patients undergoing cardiac catheterization are potentially at risk of radiation-induced health effects from the interventional fluoroscopic X-ray imaging used throughout the clinical procedure. The amount of radiation exposure is highly dependent on the complexity of the procedure and the level of optimization in imaging parameters applied by the clinician. For cardiac catheterization, patient radiation dosimetry, for key organs as well as whole-body effective, is challenging due to the lack of fixed imaging protocols, unlike other common X-ray based imaging modalities. Pediatric patients are at a greater risk compared to adults due to their greater cellular radio-sensitivities as well as longer remaining life-expectancy following the radiation exposure. In terms of radiation dosimetry, they are often more challenging due to greater variation in body size, which often triggers a wider range of imaging parameters in modern imaging systems with automatic dose rate modulation. The overall objective of this dissertation was to develop a comprehensive method of radiation dose estimation for pediatric patients undergoing cardiac catheterization. In this dissertation, the research is divided into two main parts: the Physics Component and the Clinical Component. A proof-of-principle study focused on two patient age groups (Newborn and Five-year-old), one popular biplane imaging system, and the clinical practice of two pediatric cardiologists at one large academic medical center. The Physics Component includes experiments relevant to the physical measurement of patient organ dose using high-sensitivity MOSFET dosimeters placed in anthropomorphic pediatric phantoms. First, the three-dimensional angular dependence of MOSFET detectors in scatter medium under fluoroscopic irradiation was characterized. A custom-made spherical scatter phantom was used to measure response variations in three-dimensional angular orientations. The results were to be used as angular dependence

  11. SYSTEMIC IMBALANCE OF ESSENTIAL METALS AND CARDIAC GENE EXPRESSION IN RATS FOLLOWING ACUTE PULMONARY ZINC EXPOSURE

    Science.gov (United States)

    We have recently demonstrated that PM containing water-soluble zinc may cause cardiac injury following pulmonary exposure. To investigate if pulmonary zinc exposure causes systemic metal imbalance and direct cardiac effects, we intratracheally (IT) instilled male Wistar Kyoto (WK...

  12. Pentoxifylline Attenuates Cardiac Remodeling Induced by Tobacco Smoke Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Minicucci, Marcos; Oliveira, Fernando; Santos, Priscila; Polegato, Bertha; Roscani, Meliza; Fernandes, Ana Angelica; Lustosa, Beatriz; Paiva, Sergio; Zornoff, Leonardo; Azevedo, Paula, E-mail: paulasa@fmb.unesp.br [Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, São Paulo, SP (Brazil)

    2016-05-15

    Tobacco smoke exposure is an important risk factor for cardiac remodeling. Under this condition, inflammation, oxidative stress, energy metabolism abnormalities, apoptosis, and hypertrophy are present. Pentoxifylline has anti‑inflammatory, anti-apoptotic, anti-thrombotic and anti-proliferative properties. The present study tested the hypothesis that pentoxifylline would attenuate cardiac remodeling induced by smoking. Wistar rats were distributed in four groups: Control (C), Pentoxifylline (PX), Tobacco Smoke (TS), and PX-TS. After two months, echocardiography, invasive blood pressure measurement, biochemical, and histological studies were performed. The groups were compared by two-way ANOVA with a significance level of 5%. TS increased left atrium diameter and area, which was attenuated by PX. In the isolated heart study, TS lowered the positive derivate (+dp/dt), and this was attenuated by PX. The antioxidants enzyme superoxide dismutase and glutathione peroxidase were decreased in the TS group; PX recovered these activities. TS increased lactate dehydrogenase (LDH) and decreased 3-hydroxyacyl Coenzyme A dehydrogenases (OH-DHA) and citrate synthase (CS). PX attenuated LDH, 3-OH-DHA and CS alterations in TS-PX group. TS increased IL-10, ICAM-1, and caspase-3. PX did not influence these variables. TS induced cardiac remodeling, associated with increased inflammation, oxidative stress, apoptosis, and changed energy metabolism. PX attenuated cardiac remodeling by reducing oxidative stress and improving cardiac bioenergetics, but did not act upon cardiac cytokines and apoptosis.

  13. Caffeine exposure alters cardiac gene expression in embryonic cardiomyocytes

    Science.gov (United States)

    Fang, Xiefan; Mei, Wenbin; Barbazuk, William B.; Rivkees, Scott A.

    2014-01-01

    Previous studies demonstrated that in utero caffeine treatment at embryonic day (E) 8.5 alters DNA methylation patterns, gene expression, and cardiac function in adult mice. To provide insight into the mechanisms, we examined cardiac gene and microRNA (miRNA) expression in cardiomyocytes shortly after exposure to physiologically relevant doses of caffeine. In HL-1 and primary embryonic cardiomyocytes, caffeine treatment for 48 h significantly altered the expression of cardiac structural genes (Myh6, Myh7, Myh7b, Tnni3), hormonal genes (Anp and BnP), cardiac transcription factors (Gata4, Mef2c, Mef2d, Nfatc1), and microRNAs (miRNAs; miR208a, miR208b, miR499). In addition, expressions of these genes were significantly altered in embryonic hearts exposed to in utero caffeine. For in utero experiments, pregnant CD-1 dams were treated with 20–60 mg/kg of caffeine, which resulted in maternal circulation levels of 37.3–65.3 μM 2 h after treatment. RNA sequencing was performed on embryonic ventricles treated with vehicle or 20 mg/kg of caffeine daily from E6.5-9.5. Differential expression (DE) analysis revealed that 124 genes and 849 transcripts were significantly altered, and differential exon usage (DEU) analysis identified 597 exons that were changed in response to prenatal caffeine exposure. Among the DE genes identified by RNA sequencing were several cardiac structural genes and genes that control DNA methylation and histone modification. Pathway analysis revealed that pathways related to cardiovascular development and diseases were significantly affected by caffeine. In addition, global cardiac DNA methylation was reduced in caffeine-treated cardiomyocytes. Collectively, these data demonstrate that caffeine exposure alters gene expression and DNA methylation in embryonic cardiomyocytes. PMID:25354728

  14. Non-sedating antihistamine drugs and cardiac arrhythmias -- biased risk estimates from spontaneous reporting systems?

    DEFF Research Database (Denmark)

    De Bruin, M L; van Puijenbroek, E P; Egberts, A C G

    2002-01-01

    AIMS: This study used spontaneous reports of adverse events to estimate the risk for developing cardiac arrhythmias due to the systemic use of non-sedating antihistamine drugs and compared the risk estimate before and after the regulatory action to recall the over-the-counter status of some...... of these drugs. METHODS: All suspected adverse drug reactions (ADRs) reported until July 1999 to the Netherlands Pharmacovigilance Foundation Lareb were used to calculate the ADR reporting odds ratio, defined as the ratio of exposure odds among reported arrhythmia cases, to the exposure odds of other ADRs (non......-sedating antihistamines. In general non-sedating antihistamines are associated with cardiac arrhythmia to a higher extent in comparison with other drugs (ADR reporting odds ratio 2.05 [95% CI: 1.45, 2.89]). The association between arrhythmias and non-sedating antihistamine drugs calculated before 1998...

  15. Inhibition of cardiac sodium currents by toluene exposure

    Science.gov (United States)

    Cruz, Silvia L; Orta-Salazar, Gerardo; Gauthereau, Marcia Y; Millan-Perez Peña, Lourdes; Salinas-Stefanón, Eduardo M

    2003-01-01

    Toluene is an industrial solvent widely used as a drug of abuse, which can produce sudden sniffing death due to cardiac arrhythmias. In this paper, we tested the hypothesis that toluene inhibits cardiac sodium channels in Xenopus laevis oocytes transfected with Nav1.5 cDNA and in isolated rat ventricular myocytes. In oocytes, toluene inhibited sodium currents (INa+) in a concentration-dependent manner, with an IC50 of 274 μM (confidence limits: 141–407μM). The inhibition was complete, voltage-independent, and slowly reversible. Toluene had no effect on: (i) the shape of the I–V curves; (ii) the reversal potential of Na+; and (iii) the steady-state inactivation. The slow recovery time constant from inactivation of INa+ decreased with toluene exposure, while the fast recovery time constant remained unchanged. Block of INa+ by toluene was use- and frequency-dependent. In rat cardiac myocytes, 300 μM toluene inhibited the sodium current (INa+) by 62%; this inhibition was voltage independent. These results suggest that toluene binds to cardiac Na+ channels in the open state and unbinds either when channels move between inactivated states or from an inactivated to a closed state. The use- and frequency-dependent block of INa+ by toluene might be responsible, at least in part, for its arrhythmogenic effect. PMID:14534149

  16. Estimating exposure of terrestrial wildlife to contaminants

    International Nuclear Information System (INIS)

    Sample, B.E.; Suter, G.W. II.

    1994-09-01

    This report describes generalized models for the estimation of contaminant exposure experienced by wildlife on the Oak Ridge Reservation. The primary exposure pathway considered is oral ingestion, e.g. the consumption of contaminated food, water, or soil. Exposure through dermal absorption and inhalation are special cases and are not considered hereIN. Because wildlife mobile and generally consume diverse diets and because environmental contamination is not spatial homogeneous, factors to account for variation in diet, movement, and contaminant distribution have been incorporated into the models. To facilitate the use and application of the models, life history parameters necessary to estimate exposure are summarized for 15 common wildlife species. Finally, to display the application of the models, exposure estimates were calculated for four species using data from a source operable unit on the Oak Ridge Reservation

  17. Estimating exposure of terrestrial wildlife to contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Sample, B.E.; Suter, G.W. II

    1994-09-01

    This report describes generalized models for the estimation of contaminant exposure experienced by wildlife on the Oak Ridge Reservation. The primary exposure pathway considered is oral ingestion, e.g. the consumption of contaminated food, water, or soil. Exposure through dermal absorption and inhalation are special cases and are not considered hereIN. Because wildlife mobile and generally consume diverse diets and because environmental contamination is not spatial homogeneous, factors to account for variation in diet, movement, and contaminant distribution have been incorporated into the models. To facilitate the use and application of the models, life history parameters necessary to estimate exposure are summarized for 15 common wildlife species. Finally, to display the application of the models, exposure estimates were calculated for four species using data from a source operable unit on the Oak Ridge Reservation.

  18. Radiation exposure to the child during cardiac catheterization.

    Science.gov (United States)

    Waldman, J D; Rummerfield, P S; Gilpin, E A; Kirkpatrick, S E

    1981-07-01

    Few data are available regarding radiation exposure to children during cardiac catheterization. Using lithium fluoride thermoluminescent dosimeters, radiation exposure was measured during precatheterization chest roentgenography, fluoroscopy (hemodynamic assessment phase of catheterization) and cineangiography in 30 infants and children, ages 3 days to 21 years. Dosimeters were placed over the eyes, thyroid, anterior chest, posterior chest, anterior abdomen, posterior abdomen and gonads. Average absorbed chest doses were 24.5 mR during chest roentgenography, 5810 mR during catheterization fluoroscopy and 1592 mR during cineangiography. During the complete catheterization, average doses were 26 mR to the eyes, 431 mR to the thyroid area, 150 mR to the abdomen and 11 mR to the gonads. Radiation exposure during pediatric cardiac catheterization is low to the eyes and gonads but high to the chest and thyroid area. To decrease radiation dosage we suggest (1) low pulse-rate fluoroscopy; (2) substitution of contrast echocardiography for cineangiography; (3) large-plate abdominal/gonadal shielding; (4) a selective shield for thyroid area; (5) a very small field during catheter manipulation. Minimum radiation consistent with accurate diagnosis is optimal; however, erroneous or incomplete diagnosis is more dangerous than radiation-related hazards.

  19. Radiation exposure to the child during cardiac catheterization

    International Nuclear Information System (INIS)

    Waldman, J.D.; Rummerfield, P.S.; Gilpin, E.A.; Kirkpatrick, S.E.

    1981-01-01

    Few data are available regarding radiation exposure to children during cardiac catheterization. Using lithium fluoride thermoluminescent dosimeters, radiation exposure was measured during precatheterization chest roentgenography, fluoroscopy (hemodynamic assessment phase of catheterization) and cineangiography in 30 infants and children, ages 3 days to 21 years. Dosimeters were placed over the eyes, thyroid, anterior chest, posterior chest, anterior abdomen, posterior abdomen and gonads. Average absorbed chest doses were 24.5 mR during chest roentgenography, 5810 mR during catheterization fluoroscopy and 1592 mR during cineangiography. During the complete catheterization, average doses were 26 mR to the eyes, 431 mR to the thyroid area, 150 mR to the abdomen and 11 mR to the gonads. Radiation exposure during pediatric cardiac catheterization is low to the eyes and gonads but high to the chest and thyroid area. To decrease radiation dosage we suggest (1) low pulse-rate fluoroscopy; (2) substitution of contrast echocardiography for cineangiography; (3) large-plate abdominal/gonadal shielding; (4) a selective shield for thyroid area; (5) a very small field during catheter manipulation. Minimum radiation consistent with accurate diagnosis is optimal; however, erroneous or incomplete diagnosis is more dangerous than radiation-related hazards

  20. Radiation exposure to the child during cardiac catheterization

    International Nuclear Information System (INIS)

    Waldman, J.D.; Rummerfield, P.S.; Gilpin, E.A.; Kirkpatrick, S.E.

    1981-01-01

    Few data are available regarding radiation exposure to children during cardiac catheterization. Using lithium fluoride thermoluminescent dosimeters, radiation exposure was measured during precatheterization chest roentgenography, fluoroscopy hemodynamic assessment phase of catheterization and cineangiography in 30 infants and children, ages 3 days to 21 years. Dosimeters were placed over the eyes, thyroid, anterior chest, posterior chest, anterior abdomen, posterior abdomen and gonads. Average absorbed chest doses were 24.5 mR during chest roentgenography, 5810 mR during catheterization fluoroscopy and 1592 mR during cineangiography. During the complete catheterization, average doses were 26 mR to the eyes, 431 mR to the thyroid area, 150 mR to the abdomen and 11 mR to the gonads. Radiation exposure during pediatric cardiac catheterization is low to the eyes and gonads but high to the chest and thyroid area. To decrease radiation dosage we suggest: (1) low pulse-rate fluoroscopy; (2) substitution of contrast echocardiography for cineangiography; (3) large-plate abdominal/gonadal shielding; (4) a selective shield for thyroid area; (5) a very small field during catheter manipulation. Minimum radiation consistent with accurate diagnosis is optimal; however, erroneous or incomplete diagnosis is more dangerous than radiation-related hazards

  1. Estimating Exposure of Terrestrial Wildlife to Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Sample, B.E.

    1994-01-01

    This report presents a general model for exposure of terrestrial wildlife to contaminants (Sect. 2), methods for estimating parameters of the model (Sect. 3), species specific parameters for endpoint species on the Oak Ridge Reservation (ORR) (Sect. 4), and a sample application (Sect. 5). Exposure can be defined as the coincidence in both space and time of a receptor and a stressor, such that the receptor and stressor come into contact and interact (Risk Assessment Forum 1992). In the context of ecological risk assessment, receptors include all endpoint species or communities identified for a site [see Suter (1989) and Suter et al. (1994) for discussions of ecological endpoints for waste sites]. In the context of waste site assessments, stressors are chemical contaminations, and the contact and interaction are uptake of the contaminant by the receptor. Without sufficient exposure of the receptor to the contaminants, there is no ecological risk. Unlike some other endpoint assemblages, terrestrial wildlife are significantly exposed to contaminants in multiple media. They may drink or swim in contaminated water, ingest contaminated food and soil, and breath contaminated air. In addition, because most wildlife are mobile, moving among and within habitats, exposure is not restricted to a single location. They may integrate contamination from several spatially discrete sources. Therefore, exposure models for terrestrial wildlife must include multiple media. This document provides models and parameters for estimating exposure of birds and mammals. Reptiles and amphibians are not considered because few data exist with which to assess exposure to these organisms. In addition, because toxicological data are scarce for both classes, evaluation of the significance of exposure estimates is problematic. However, the general exposure estimation procedure developed herein for birds and mammals is applicable to reptiles and amphibians. Exposure models must be appropriate to the

  2. Evaluating low pass filters on SPECT reconstructed cardiac orientation estimation

    Science.gov (United States)

    Dwivedi, Shekhar

    2009-02-01

    Low pass filters can affect the quality of clinical SPECT images by smoothing. Appropriate filter and parameter selection leads to optimum smoothing that leads to a better quantification followed by correct diagnosis and accurate interpretation by the physician. This study aims at evaluating the low pass filters on SPECT reconstruction algorithms. Criteria for evaluating the filters are estimating the SPECT reconstructed cardiac azimuth and elevation angle. Low pass filters studied are butterworth, gaussian, hamming, hanning and parzen. Experiments are conducted using three reconstruction algorithms, FBP (filtered back projection), MLEM (maximum likelihood expectation maximization) and OSEM (ordered subsets expectation maximization), on four gated cardiac patient projections (two patients with stress and rest projections). Each filter is applied with varying cutoff and order for each reconstruction algorithm (only butterworth used for MLEM and OSEM). The azimuth and elevation angles are calculated from the reconstructed volume and the variation observed in the angles with varying filter parameters is reported. Our results demonstrate that behavior of hamming, hanning and parzen filter (used with FBP) with varying cutoff is similar for all the datasets. Butterworth filter (cutoff > 0.4) behaves in a similar fashion for all the datasets using all the algorithms whereas with OSEM for a cutoff < 0.4, it fails to generate cardiac orientation due to oversmoothing, and gives an unstable response with FBP and MLEM. This study on evaluating effect of low pass filter cutoff and order on cardiac orientation using three different reconstruction algorithms provides an interesting insight into optimal selection of filter parameters.

  3. Joint Estimation of Cardiac Toxicity and Recurrence Risks After Comprehensive Nodal Photon Versus Proton Therapy for Breast Cancer

    DEFF Research Database (Denmark)

    Stick, Line B; Yu, Jen; Maraldo, Maja V

    2017-01-01

    PURPOSE: The study aims to perform joint estimation of the risk of recurrence caused by inadequate radiation dose coverage of lymph node targets and the risk of cardiac toxicity caused by radiation exposure to the heart. Delivered photon plans are compared with realistic proton plans, thereby pro...

  4. Estimating retrospective exposure of household humidifier disinfectants.

    Science.gov (United States)

    Park, D U; Friesen, M C; Roh, H S; Choi, Y Y; Ahn, J J; Lim, H K; Kim, S K; Koh, D H; Jung, H J; Lee, J H; Cheong, H K; Lim, S Y; Leem, J H; Kim, Y H; Paek, D M

    2015-12-01

    We conducted a comprehensive humidifier disinfectant exposure characterization for 374 subjects with lung disease who presumed their disease was related to humidifier disinfectant use (patient group) and for 303 of their family members (family group) for an ongoing epidemiological study. We visited the homes of the registered patients to investigate disinfectant use characteristics. Probability of exposure to disinfectants was determined from the questionnaire and supporting evidence from photographs demonstrating the use of humidifier disinfectant, disinfectant purchase receipts, any residual disinfectant, and the consistency of their statements. Exposure duration was estimated as cumulative disinfectant use hours from the questionnaire. Airborne disinfectant exposure intensity (μg/m(3)) was estimated based on the disinfectant volume (ml) and frequency added to the humidifier per day, disinfectant bulk level (μg/ml), the volume of the room (m(3)) with humidifier disinfectant, and the degree of ventilation. Overall, the distribution patterns of the intensity, duration, and cumulative exposure to humidifier disinfectants for the patient group were higher than those of the family group, especially for pregnant women and patients ≤6 years old. Further study is underway to evaluate the association between the disinfectant exposures estimated here with clinically diagnosed lung disease. Retrospective exposure to household humidifier disinfectant as estimated here can be used to evaluate associations with clinically diagnosed lung disease due to the use of humidifier disinfectant in Korea. The framework, with modifications to account for dispersion and use patterns, can also be potentially adapted to assessment of other household chemical exposures. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. External beam radiotherapy (EBRT) techniques used in breast cancer treatment to reduce cardiac exposure

    International Nuclear Information System (INIS)

    Fung, Esther; Hendry, Julie

    2013-01-01

    Radiotherapy in breast cancer treatment has been shown to reduce local recurrence and improve survival rates. However, there is a concern that breast radiotherapy can cause an increase in cardiac mortality, particularly in patients being treated for left-sided breast cancer. This review aims to investigate how cardiac exposure is minimised in breast radiotherapy and determine an optimal method for reducing cardiac dose, using literature from ScienceDirect, Medline and CINAHL. IMRT and breathing-adapted radiotherapy both reduce cardiac exposure but IMRT also increases the irradiated volume at low dose. Several issues were reported with regards to the clinical implementation of these techniques. It is suggested that inspiration breath-hold radiotherapy, is the preferred solution to minimising cardiac exposure but more research is warranted to confirm this. Long-term follow-up is required to determine dose–response relationships. Research needs to focus on breast cancer treatment as a whole in order to effectively reduce cardiac mortality.

  6. Cardiac output estimation using pulmonary mechanics in mechanically ventilated patients

    Directory of Open Access Journals (Sweden)

    Hann Christopher E

    2010-11-01

    Full Text Available Abstract The application of positive end expiratory pressure (PEEP in mechanically ventilated (MV patients with acute respiratory distress syndrome (ARDS decreases cardiac output (CO. Accurate measurement of CO is highly invasive and is not ideal for all MV critically ill patients. However, the link between the PEEP used in MV, and CO provides an opportunity to assess CO via MV therapy and other existing measurements, creating a CO measure without further invasiveness. This paper examines combining models of diffusion resistance and lung mechanics, to help predict CO changes due to PEEP. The CO estimator uses an initial measurement of pulmonary shunt, and estimations of shunt changes due to PEEP to predict CO at different levels of PEEP. Inputs to the cardiac model are the PV loops from the ventilator, as well as the oxygen saturation values using known respiratory inspired oxygen content. The outputs are estimates of pulmonary shunt and CO changes due to changes in applied PEEP. Data from two published studies are used to assess and initially validate this model. The model shows the effect on oxygenation due to decreased CO and decreased shunt, resulting from increased PEEP. It concludes that there is a trade off on oxygenation parameters. More clinically importantly, the model also examines how the rate of CO drop with increased PEEP can be used as a method to determine optimal PEEP, which may be used to optimise MV therapy with respect to the gas exchange achieved, as well as accounting for the impact on the cardiovascular system and its management.

  7. Risk estimates for exposure to alpha emitters

    International Nuclear Information System (INIS)

    1982-07-01

    The primary scope of this report is to evaluate the risk of lung cancer from occupational exposure to short-lived daughters of radon and thoron. The Subcommittee on Risk Estimates considers that inhalation of radon and thoron daughters is the major radiation hazard from alpha radiation in uranium mining. The secondary scope of this report is the consideration of the applicability of the risk estimates derived from miners to the general public. The risk to members of the public from radium-226 in drinking water is also considered. Some research requirments are suggested

  8. Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate

    OpenAIRE

    Kerr, Zachary Y.; Littleton, Ashley C.; Cox, Leah M.; DeFreese, J.D.; Varangis, Eleanna; Lynall, Robert C.; Schmidt, Julianne D.; Marshall, Stephen W.; Guskiewicz, Kevin M.

    2015-01-01

    Over the past decade, there has been significant debate regarding the effect of cumulative subconcussive head impacts on short and long-term neurological impairment. This debate remains unresolved, because valid epidemiological estimates of athletes' total contact exposure are lacking. We present a measure to estimate the total hours of contact exposure in football over the majority of an athlete's lifespan. Through a structured oral interview, former football players provided information rel...

  9. Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate.

    Science.gov (United States)

    Kerr, Zachary Y; Littleton, Ashley C; Cox, Leah M; DeFreese, J D; Varangis, Eleanna; Lynall, Robert C; Schmidt, Julianne D; Marshall, Stephen W; Guskiewicz, Kevin M

    2015-07-15

    Over the past decade, there has been significant debate regarding the effect of cumulative subconcussive head impacts on short and long-term neurological impairment. This debate remains unresolved, because valid epidemiological estimates of athletes' total contact exposure are lacking. We present a measure to estimate the total hours of contact exposure in football over the majority of an athlete's lifespan. Through a structured oral interview, former football players provided information related to primary position played and participation in games and practice contacts during the pre-season, regular season, and post-season of each year of their high school, college, and professional football careers. Spring football for college was also included. We calculated contact exposure estimates for 64 former football players (n = 32 college football only, n = 32 professional and college football). The head impact exposure estimate (HIEE) discriminated between individuals who stopped after college football, and individuals who played professional football (p < 0.001). The HIEE measure was independent of concussion history (p = 0.82). Estimating total hours of contact exposure may allow for the detection of differences between individuals with variation in subconcussive impacts, regardless of concussion history. This measure is valuable for the surveillance of subconcussive impacts and their associated potential negative effects.

  10. Effects of exposure estimation errors on estimated exposure-response relations for PM2.5.

    Science.gov (United States)

    Cox, Louis Anthony Tony

    2018-07-01

    Associations between fine particulate matter (PM2.5) exposure concentrations and a wide variety of undesirable outcomes, from autism and auto theft to elderly mortality, suicide, and violent crime, have been widely reported. Influential articles have argued that reducing National Ambient Air Quality Standards for PM2.5 is desirable to reduce these outcomes. Yet, other studies have found that reducing black smoke and other particulate matter by as much as 70% and dozens of micrograms per cubic meter has not detectably affected all-cause mortality rates even after decades, despite strong, statistically significant positive exposure concentration-response (C-R) associations between them. This paper examines whether this disconnect between association and causation might be explained in part by ignored estimation errors in estimated exposure concentrations. We use EPA air quality monitor data from the Los Angeles area of California to examine the shapes of estimated C-R functions for PM2.5 when the true C-R functions are assumed to be step functions with well-defined response thresholds. The estimated C-R functions mistakenly show risk as smoothly increasing with concentrations even well below the response thresholds, thus incorrectly predicting substantial risk reductions from reductions in concentrations that do not affect health risks. We conclude that ignored estimation errors obscure the shapes of true C-R functions, including possible thresholds, possibly leading to unrealistic predictions of the changes in risk caused by changing exposures. Instead of estimating improvements in public health per unit reduction (e.g., per 10 µg/m 3 decrease) in average PM2.5 concentrations, it may be essential to consider how interventions change the distributions of exposure concentrations. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Joint Estimation of Cardiac Toxicity and Recurrence Risks After Comprehensive Nodal Photon Versus Proton Therapy for Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Stick, Line B., E-mail: line.bjerregaard.stick@regionh.dk [Department of Clinical Oncology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Niels Bohr Institute, Faculty of Science, University of Copenhagen, Copenhagen (Denmark); Yu, Jen [Maryland Proton Treatment Center, University of Maryland School of Medicine, Baltimore, Maryland (United States); Maraldo, Maja V. [Department of Clinical Oncology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Aznar, Marianne C. [Department of Clinical Oncology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Nuffield Department of Population Health, University of Oxford, Oxford (United Kingdom); Pedersen, Anders N. [Department of Clinical Oncology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Bentzen, Søren M. [Department of Clinical Oncology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Maryland Proton Treatment Center, University of Maryland School of Medicine, Baltimore, Maryland (United States); Greenebaum Comprehensive Cancer Center and Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland (United States); Vogelius, Ivan R. [Department of Clinical Oncology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark)

    2017-03-15

    Purpose: The study aims to perform joint estimation of the risk of recurrence caused by inadequate radiation dose coverage of lymph node targets and the risk of cardiac toxicity caused by radiation exposure to the heart. Delivered photon plans are compared with realistic proton plans, thereby providing evidence-based estimates of the heterogeneity of treatment effects in consecutive cases for the 2 radiation treatment modalities. Methods and Materials: Forty-one patients referred for postlumpectomy comprehensive nodal photon irradiation for left-sided breast cancer were included. Comparative proton plans were optimized by a spot scanning technique with single-field optimization from 2 en face beams. Cardiotoxicity risk was estimated with the model of Darby et al, and risk of recurrence following a compromise of lymph node coverage was estimated by a linear dose-response model fitted to the recurrence data from the recently published EORTC (European Organisation for Research and Treatment of Cancer) 22922/10925 and NCIC-CTG (National Cancer Institute of Canada Clinical Trials Group) MA.20 randomized controlled trials. Results: Excess absolute risk of cardiac morbidity was small with photon therapy at an attained age of 80 years, with median values of 1.0% (range, 0.2%-2.9%) and 0.5% (range, 0.03%-1.0%) with and without cardiac risk factors, respectively, but even lower with proton therapy (0.13% [range, 0.02%-0.5%] and 0.06% [range, 0.004%-0.3%], respectively). The median estimated excess absolute risk of breast cancer recurrence after 10 years was 0.10% (range, 0.0%-0.9%) with photons and 0.02% (range, 0.0%-0.07%) with protons. The association between age of the patient and benefit from proton therapy was weak, almost non-existing (Spearman rank correlations of −0.15 and −0.30 with and without cardiac risk factors, respectively). Conclusions: Modern photon therapy yields limited risk of cardiac toxicity in most patients, but proton therapy can reduce the

  12. DNA damage in lymphocytes induced by cardiac CT and comparison with physical exposure parameters

    Energy Technology Data Exchange (ETDEWEB)

    Fukumoto, Wataru; Tatsugami, Fuminari; Awai, Kazuo [Department of Diagnostic Radiology, Institute of Biomedical Health Sciences, Hiroshima University, Hiroshima (Japan); Ishida, Mari; Sakai, Chiemi [Institute of Biomedical and Health Sciences, Department of Cardiovascular Physiology and Medicine, Hiroshima University, Hiroshima (Japan); Tashiro, Satoshi [Hiroshima University, Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima (Japan); Ishida, Takafumi [Institute of Clinical Research West Medical Center, Hiroshima (Japan); Nakano, Yukiko [Hiroshima University Hospital, Department of Cardiovascular Medicine, Hiroshima (Japan)

    2017-04-15

    To investigate whether physical exposure parameters such as the dose index (CTDI), dose length product (DLP), and size-specific dose estimate (SSDE) are predictive of DNA damage. In vitro, we scanned a phantom containing blood samples from five volunteers at CTDI 50, 100, and 150 mGy. One sample was not scanned. We also scanned samples in three different-size phantoms at CTDI 100 mGy. In vivo, we enrolled 45 patients and obtained blood samples before and after cardiac CT. The γ-H2AX foci were counted. In vitro, in the control and at CTDI 50, 100, and 150 mGy, the number of γ-H2AX was 0.94 ± 0.24 (standard error, SE), 1.28 ± 0.30, 1.91 ± 0.47, and 2.16 ± 0.20. At SSDE 180, 156, and 135 mGy, it was 2.41 ± 0.20, 1.91 ± 0.47, and 1.42 ± 0.20 foci/cell. The γ-H2AX foci were positively correlated with the radiation dose and negatively correlated with the body size. In vivo, the γ-H2AX foci were significantly increased after CT (from 1.21 ± 0.19 to 1.92 ± 0.22 foci/cell) and correlated with CTDI, DLP, and SSDE. DNA damage was induced by cardiac CT. There was a correlation between the physical exposure parameters and γ-H2AX. (orig.)

  13. Estimation of health risks from radiation exposures

    Energy Technology Data Exchange (ETDEWEB)

    Randolph, M.L.

    1983-08-01

    An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks.

  14. Estimation of health risks from radiation exposures

    International Nuclear Information System (INIS)

    Randolph, M.L.

    1983-08-01

    An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks

  15. Motion estimation of tagged cardiac magnetic resonance images using variational techniques

    Czech Academy of Sciences Publication Activity Database

    Carranza-Herrezuelo, N.; Bajo, A.; Šroubek, Filip; Santamarta, C.; Cristóbal, G.; Santos, A.; Ledesma-Carbayo, M.J.

    2010-01-01

    Roč. 34, č. 6 (2010), s. 514-522 ISSN 0895-6111 Institutional research plan: CEZ:AV0Z10750506 Keywords : medical imaging processing * motion estimation * variational techniques * tagged cardiac magnetic resonance images * optical flow Subject RIV: JD - Computer Applications, Robotics Impact factor: 1.110, year: 2010 http://library.utia.cas.cz/separaty/2010/ZOI/sroubek- motion estimation of tagged cardiac magnetic resonance images using variational techniques.pdf

  16. Cardiac and Metabolic Effects of Dietary Selenomethionine Exposure in Adult Zebrafish.

    Science.gov (United States)

    Pettem, Connor M; Weber, Lynn P; Janz, David M

    2017-10-01

    Selenium (Se) is an essential micronutrient involved in important metabolic functions for all vertebrate species. As Se is reported to have a narrow margin between essentiality and toxicity, there is growing concern surrounding the adverse effects of elevated Se exposure caused by anthropogenic activities. Recent studies have reported that elevated dietary exposure of fish to selenomethionine (Se-Met) can alter aerobic metabolic capacity, energetics and swimming performance. This study aims to further investigate mechanisms of sublethal Se-Met toxicity, particularly potential underlying cardiovascular implications of chronic exposure to environmentally relevant concentrations of dietary Se-Met in adult zebrafish (Danio rerio). Adult zebrafish were fed either control food (1.1 μg Se/g dry mass [d.m.]) or Se-Met spiked food (10.3 or 28.8 μg Se/g d.m.) for 90 d at 5% body weight per day. Following exposure, ultrahigh resolution B-mode and Doppler ultrasound was used to characterize cardiac function. Chronic dietary exposure to elevated Se-Met significantly reduced ventricular contractile rate, stroke volume, and cardiac output. Exposure to Se-Met significantly decreased mRNA expression of methionine adenosyltransferase 1 alpha and glutathione-S-transferase pi class in liver, and a key cardiac remodelling enzyme, matrix metalloproteinase 2, in adult zebrafish heart. Se-Met significantly increased echodensity at the junction between atrium and ventricle, and these results combined with increased matrix metalloproteinase 2 expression are consistent with cardiac remodelling and fibrosis. The results of this study suggest that chronic exposure to dietary Se-Met can negatively impact cardiac function, and such physiological consequences could reduce the aerobic capacity and survivability of fish. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. A single exposure to photochemical smog causes airway irritation and cardiac dysrhythmia in mice

    Science.gov (United States)

    The data presented here shows that a single exposure to photochemical smog causes airway irritation and cardiac dysrhythmia in mice. Smog, which is a complex mixture of particulate matter and gaseous irritants (ozone, sulfur dioxide, reactive aldehydes), as well as components whi...

  18. Primary carnitine deficiency and pivalic acid exposure causing encephalopathy and fatal cardiac events

    DEFF Research Database (Denmark)

    Rasmussen, Jan; Nielsen, Olav W; Lund, Allan M

    2013-01-01

    Several episodes of sudden death among young Faroese individuals have been associated with primary carnitine deficiency (PCD). Patients suffering from PCD have low carnitine levels and can present with metabolic and/or cardiac complications. Pivalic acid exposure decreases carnitine levels...

  19. Carbon monoxide exposure enhances arrhythmia after cardiac stress: involvement of oxidative stress.

    Science.gov (United States)

    André, Lucas; Gouzi, Fares; Thireau, Jérôme; Meyer, Gregory; Boissiere, Julien; Delage, Martine; Abdellaoui, Aldja; Feillet-Coudray, Christine; Fouret, Gilles; Cristol, Jean-Paul; Lacampagne, Alain; Obert, Philippe; Reboul, Cyril; Fauconnier, Jérémy; Hayot, Maurice; Richard, Sylvain; Cazorla, Olivier

    2011-11-01

    Arrhythmias following cardiac stress are a key predictor of death in healthy population. Carbon monoxide (CO) is a ubiquitous pollutant promoting oxidative stress and associated with hospitalization for cardiovascular disease and cardiac mortality. We investigated the effect of chronic CO exposure on the occurrence of arrhythmic events after a cardiac stress test and the possible involvement of related oxidative stress. Wistar rats exposed chronically (4 weeks) to sustained urban CO pollution presented more arrhythmic events than controls during recovery after cardiac challenge with isoprenaline in vivo. Sudden death occurred in 22% of CO-exposed rats versus 0% for controls. Malondialdehyde (MDA), an end-product of lipid peroxidation, was increased in left ventricular tissue of CO-exposed rats. Cardiomyocytes isolated from CO-exposed rats showed higher reactive oxygen species (ROS) production (measured with MitoSox Red dye), higher diastolic Ca(2+) resulting from SR calcium leak and an higher occurrence of irregular Ca(2+) transients (measured with Indo-1) in comparison to control cells after a high pacing sequence. Acute treatment with a ROS scavenger (N-acetylcysteine, 20 mmol/L, 1 h) prevented this sequence of alterations and decreased the number of arrhythmic cells following high pacing. Chronic CO exposure promotes oxidative stress that alters Ca(2+) homeostasis (through RYR2 and SERCA defects) and thereby mediates the triggering of ventricular arrhythmia after cardiac stress that can lead to sudden death.

  20. Deinhibition of cardiac Na+-K+-ATPase after exposure to exogenous phospholipase A2

    International Nuclear Information System (INIS)

    Colvin, R.A.

    1987-01-01

    After 2 h of exogenous phospholipase A 2 (PLA 2 ) exposure, membrane phospholipid decreased from 3.22 +/- 0.31 to 1.06 +/- 0.13 μmol/mg (33% of control). All classes of phospholipid, except sphingomyelin, were hydrolyzed, whereas total cholesterol content was unaffected. Increases in nonesterified fatty acids (NEFA) were reflected primarily in oleic (18:1), linoleic (18:2), and arachidonic (20:4). Na + -K + -adenosinetriphosphatase (ATPase) activity was inhibited to 29% of control by 2 h of PLA 2 treatment, and this inhibition was reversed (albeit, not completely after 5 min of PLA 2 treatment) by removal of the hydrolysis products with 0.1% bovine serum albumin (BSA). In contrast, the apparent binding capacity for [ 3 H]ouabain was not affected by PLA 2 treatment. Unmasking of latent [ 3 H]ouabain binding by alamethicin was utilized to estimate changes in the proportion of sealed vesicles present before and after PLA 2 treatment. PLA 2 treatment resulted in a time-dependent loss of sealed vesicles that paralleled the time course of phospholipid hydrolysis and was not reversed by washing with BSA. These studies demonstrate that cardiac Na + -K + -ATPase activity is inhibited by accumulation of endogenously produced lysophospholipids and NEFA. In contrast, loss of vesicle integrity may result from both accumulation of endogenously produced hydrolysis products and membrane phospholipid depletion

  1. Rationale and design of the worldwide prospective multicenter registry on radiation dose estimates of cardiac CT angiography in daily practice in 2017 (PROTECTION VI)

    DEFF Research Database (Denmark)

    Stocker, Thomas J; Deseive, Simon; Chen, Marcus

    2018-01-01

    -randomized and randomized studies have been performed to reduce the associated radiation exposure. Currently, it is unclear if the advances in technology and knowledge about radiation reduction translated into reduced levels of cardiac CTA radiation dose in daily clinical practice as well as a wide utilization of dose......-saving strategies. METHODS: The PROTECTION VI study is a multicenter, prospective, worldwide registry designed to evaluate radiation dose exposure, utilization of dose-saving strategies and diagnostic image quality during cardiac CTA in current daily practice. Assessment of image quality will be addressed...... median radiation dose levels, image quality, frequency of use and efficacy of algorithms for dose reduction, and patient and study-related predictors associated with radiation dose. CONCLUSIONS: The PROTECTION VI study is designed to provide a reliable estimate of current radiation dose for cardiac CTA...

  2. Value of electron beam tomography (EBT). II. non-cardiac applications and radiation exposure

    International Nuclear Information System (INIS)

    Enzweiler, C.N.H.; Lembcke, A.; Rogalla, P.; Taupitz, M.; Wiese, T.H.; Hamm, B.; Becker, C.R.; Bruening, R.; Reiser, M.F.; Schoepf, U.J.; Felix, R.; Knollmann, F.D.; Georgi, M.; Weisser, G.; Lehmann, K.J.

    2004-01-01

    Electron beam tomography (EBT) has been scientifically evaluated to a much lesser degree for non-cardiac indications than for cardiac purposes. Therefore, four groups of investigators in Berlin (2), Mannheim and Muenchen, which were supported by the Deutsche Forschungsgemeinschaft (DFG), included applications outside the heart in their evaluation of EBT technology. EBT has proven useful to look for pulmonary embolism and to assess other vessels (aorta, aortic branches, and intracranial arteries). Imaging of the lung parenchyma benefits from its intrinsic high contrast and from the fast data acquisition of EBT. Limited photon efficiency, higher radiation exposure, increased noise levels and other artifacts, however markedly reduce the value of EBT for imaging of low contrast objects compared to conventional spiral CT and multislice CT (MSCT), compromising, in particular, the morphologic depiction of parenchymal abdominal organs and the brain. Consequently, scientific studies to further evaluate EBT for scanning of the brain and parenchymal abdominal organs were not pursued. Radiation exposure for non-cardiac EBT studies is up to three times higher than that for respective spiral CT studies, and in children EBT can only be advocated in select cases. Radiation exposure for the various prospectively triggered cardiac examination protocols of EBT is lower than that for conventional coronary angiography. Radiation exposure in cardiac multislice CT exceeds severalfold that of EBT, but the dose efficiency of EBT and MSCT are similar due to higher spatial resolution and less image noise of MSCT. In addition, modifications of MSCT (ECG pulsing) can further reduce radiation exposure to the level of EBT. Technical improvements of the EBT successor scanner 'e-Speed' enable faster data acquisiton at higher spatial resolution. Within comparative studies, the 'e-Speed' will have to prove its value and competitiveness, particularly in comparison with multislice CT. After profound

  3. Optimal algorithm switching for the estimation of systole period from cardiac microacceleration signals (SonR).

    Science.gov (United States)

    Giorgis, L; Frogerais, P; Amblard, A; Donal, E; Mabo, P; Senhadji, L; Hernández, A I

    2012-11-01

    Previous studies have shown that cardiac microacceleration signals, recorded either cutaneously, or embedded into the tip of an endocardial pacing lead, provide meaningful information to characterize the cardiac mechanical function. This information may be useful to personalize and optimize the cardiac resynchronization therapy, delivered by a biventricular pacemaker, for patients suffering from chronic heart failure (HF). This paper focuses on the improvement of a previously proposed method for the estimation of the systole period from a signal acquired with a cardiac microaccelerometer (SonR sensor, Sorin CRM SAS, France). We propose an optimal algorithm switching approach, to dynamically select the best configuration of the estimation method, as a function of different control variables, such as the signal-to-noise ratio or heart rate. This method was evaluated on a database containing recordings from 31 patients suffering from chronic HF and implanted with a biventricular pacemaker, for which various cardiac pacing configurations were tested. Ultrasound measurements of the systole period were used as a reference and the improved method was compared with the original estimator. A reduction of 11% on the absolute estimation error was obtained for the systole period with the proposed algorithm switching approach.

  4. Assessment of cardiac exposure in left-tangential breast irradiation

    International Nuclear Information System (INIS)

    Vees, H.; Bigler, R.; Gruber, G.; Bieri, S.

    2011-01-01

    Purpose. - To assess the value of treatment-planning related parameters namely, the breast volume; the distance of the inferior field border to diaphragm; and the cardio-thoracic ratio for left-tangential breast irradiation. Patients and methods. - Treatment plans of 27 consecutively left-sided breast cancer patients after breast conserving surgery were evaluated for several parameters concerning heart-irradiation. We measured the heart distance respective to the cardio-thoracic ratio and the distance of the inferior field border to diaphragm, as well as the breast volume in correlation with the irradiated heart volume. Results. - The mean heart and left breast volumes were 504 cm 3 and 672.8 cm 3 , respectively. The mean heart diameter was 13.4 cm; the mean cardio-thoracic ratio 0.51 and the mean distance of the inferior field border to diaphragm was 1.4 cm. Cardio-thoracic ratio (p = 0.01), breast volume (p = 0.0002), distance of the inferior field border to diaphragm (p = 0.02) and central lung distance (p = 0.02) were significantly correlated with the measured heart distance. A significant correlation was also found between cardio-thoracic ratio, breast volume and distance of the inferior field border to diaphragm with the irradiated heart volume measured by V10, V20 and V40. Conclusion. - The verification of parameters like cardio-thoracic ratio, distance of the inferior field border to diaphragm and breast volume in left-sided breast cancer patients may help in determining which patients could benefit from more complex planning techniques such as intensity-modulated radiotherapy to reduced risk of late cardiac injury. (authors)

  5. Reducing operator radiation exposure during cardiac resynchronization therapy.

    Science.gov (United States)

    Brambilla, Marco; Occhetta, Eraldo; Ronconi, Martina; Plebani, Laura; Carriero, Alessandro; Marino, Paolo

    2010-12-01

    To quantify the reduction in equivalent dose at operator's hand that can be achieved by placement of a radiation-absorbing drape (RADPAD) during long-lasting cardiac resynchronization therapy (CRT) procedures. This is a prospective observational study that included 22 consecutive patients with drug-refractory heart failure who underwent implantation of a CRT device. The cases were randomly assigned to Group A (11 cases), performed without RADPAD, and to Group B (11 cases), performed using RADPAD. Dose equivalent at the examiner's hand was measured as H(p)(0.07) and as a time-adjusted H(p)(0.07) rate (mGy/min) with a direct reading dosimeter. The mean fluoroscopy time was 20.8 ± 7.7 min and the mean dose area product (DAP) was 118.6 ± 45.3 Gy cm(2). No significant differences were found between body mass index, fluoroscopy time, and DAP between patients examined with or without RADPAD. The correlation between the fluoroscopy time and the DAP was high (R(2) = 0.94, P RADPAD at the finger and hand were H(p)(0.07) = 1.27 ± 0.47 mGy per procedure and H(p)(0.07) rate = 0.057 ± 0.011 mGy/min, respectively. The dosage was reduced with the RADPAD to H(p)(0.07) = 0.48 ± 0.20 (P RADPAD. The use of the RADPAD in CRT devices implantation will make unlikely the necessity of limiting the yearly number of implants for high volume operators.

  6. Estimators for longitudinal latent exposure models: examining measurement model assumptions.

    Science.gov (United States)

    Sánchez, Brisa N; Kim, Sehee; Sammel, Mary D

    2017-06-15

    Latent variable (LV) models are increasingly being used in environmental epidemiology as a way to summarize multiple environmental exposures and thus minimize statistical concerns that arise in multiple regression. LV models may be especially useful when multivariate exposures are collected repeatedly over time. LV models can accommodate a variety of assumptions but, at the same time, present the user with many choices for model specification particularly in the case of exposure data collected repeatedly over time. For instance, the user could assume conditional independence of observed exposure biomarkers given the latent exposure and, in the case of longitudinal latent exposure variables, time invariance of the measurement model. Choosing which assumptions to relax is not always straightforward. We were motivated by a study of prenatal lead exposure and mental development, where assumptions of the measurement model for the time-changing longitudinal exposure have appreciable impact on (maximum-likelihood) inferences about the health effects of lead exposure. Although we were not particularly interested in characterizing the change of the LV itself, imposing a longitudinal LV structure on the repeated multivariate exposure measures could result in high efficiency gains for the exposure-disease association. We examine the biases of maximum likelihood estimators when assumptions about the measurement model for the longitudinal latent exposure variable are violated. We adapt existing instrumental variable estimators to the case of longitudinal exposures and propose them as an alternative to estimate the health effects of a time-changing latent predictor. We show that instrumental variable estimators remain unbiased for a wide range of data generating models and have advantages in terms of mean squared error. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  7. Model-based estimation for dynamic cardiac studies using ECT

    International Nuclear Information System (INIS)

    Chiao, P.C.; Rogers, W.L.; Clinthorne, N.H.; Fessler, J.A.; Hero, A.O.

    1994-01-01

    In this paper, the authors develop a strategy for joint estimation of physiological parameters and myocardial boundaries using ECT (Emission Computed Tomography). The authors construct an observation model to relate parameters of interest to the projection data and to account for limited ECT system resolution and measurement noise. The authors then use a maximum likelihood (ML) estimator to jointly estimate all the parameters directly from the projection data without reconstruction of intermediate images. The authors also simulate myocardial perfusion studies based on a simplified heart model to evaluate the performance of the model-based joint ML estimator and compare this performance to the Cramer-Rao lower bound. Finally, model assumptions and potential uses of the joint estimation strategy are discussed

  8. Model-based estimation for dynamic cardiac studies using ECT.

    Science.gov (United States)

    Chiao, P C; Rogers, W L; Clinthorne, N H; Fessler, J A; Hero, A O

    1994-01-01

    The authors develop a strategy for joint estimation of physiological parameters and myocardial boundaries using ECT (emission computed tomography). They construct an observation model to relate parameters of interest to the projection data and to account for limited ECT system resolution and measurement noise. The authors then use a maximum likelihood (ML) estimator to jointly estimate all the parameters directly from the projection data without reconstruction of intermediate images. They also simulate myocardial perfusion studies based on a simplified heart model to evaluate the performance of the model-based joint ML estimator and compare this performance to the Cramer-Rao lower bound. Finally, the authors discuss model assumptions and potential uses of the joint estimation strategy.

  9. Estimation of dose and exposure at sentinel node study

    International Nuclear Information System (INIS)

    Skopljak, A.; Kucukalic-Selimovic, E.; Beslic, N.; Begic, A.; Begovic-Hadzimuratovic, S.; Drazeta, Z.; Beganovic, A.

    2005-01-01

    The purpose of this study was to estimate the dose end exposure in staff involved in sentinel node procedure for breast cancer patients. The Institute of Nuclear Medicine in Sarajevo uses a protocol for lymphoscintigraphy of the sentinel node whereby 13 MBq of 9 9mT c nanocoll are used. In this study, we measured radiation doses and exposure of a nuclear medicine physician and a technologist, as well as a surgeon performing sentinel node lymphoscintigraphy and biopsy. Dose and exposure were calculated using the equation in which we have gamma constant for 9 9mT c. Calculations were made for different times of exposure and distance. In Table 1. we estimated the dose and exposure during sentinel node study. Radiation levels were very low and the most exposed hospital staff performing sentinel node study were nuclear medicine physicians. The doses on the hands of surgeons were negligible 8 hours after exposure.(author)

  10. Cytogenetic biological dosimetry. Dose estimative in accidental exposure

    International Nuclear Information System (INIS)

    Santos, O.R. dos; Campos, I.M.A. de.

    1988-01-01

    The methodology of cytogenetic biological dosimetry is studied. The application in estimation of dose in five cases of accidental exposure is reported. An hematological study and culture of lymphocytes is presented. (M.A.C.) [pt

  11. Population Exposure Estimates in Proximity to Nuclear Power Plants, Locations

    Data.gov (United States)

    National Aeronautics and Space Administration — The Population Exposure Estimates in Proximity to Nuclear Power Plants, Locations data set combines information from a global data set developed by Declan Butler of...

  12. Dual respiratory and cardiac motion estimation in PET imaging: Methods design and quantitative evaluation.

    Science.gov (United States)

    Feng, Tao; Wang, Jizhe; Tsui, Benjamin M W

    2018-04-01

    The goal of this study was to develop and evaluate four post-reconstruction respiratory and cardiac (R&C) motion vector field (MVF) estimation methods for cardiac 4D PET data. In Method 1, the dual R&C motions were estimated directly from the dual R&C gated images. In Method 2, respiratory motion (RM) and cardiac motion (CM) were separately estimated from the respiratory gated only and cardiac gated only images. The effects of RM on CM estimation were modeled in Method 3 by applying an image-based RM correction on the cardiac gated images before CM estimation, the effects of CM on RM estimation were neglected. Method 4 iteratively models the mutual effects of RM and CM during dual R&C motion estimations. Realistic simulation data were generated for quantitative evaluation of four methods. Almost noise-free PET projection data were generated from the 4D XCAT phantom with realistic R&C MVF using Monte Carlo simulation. Poisson noise was added to the scaled projection data to generate additional datasets of two more different noise levels. All the projection data were reconstructed using a 4D image reconstruction method to obtain dual R&C gated images. The four dual R&C MVF estimation methods were applied to the dual R&C gated images and the accuracy of motion estimation was quantitatively evaluated using the root mean square error (RMSE) of the estimated MVFs. Results show that among the four estimation methods, Methods 2 performed the worst for noise-free case while Method 1 performed the worst for noisy cases in terms of quantitative accuracy of the estimated MVF. Methods 4 and 3 showed comparable results and achieved RMSE lower by up to 35% than that in Method 1 for noisy cases. In conclusion, we have developed and evaluated 4 different post-reconstruction R&C MVF estimation methods for use in 4D PET imaging. Comparison of the performance of four methods on simulated data indicates separate R&C estimation with modeling of RM before CM estimation (Method 3) to be

  13. Exposure to occupational air pollution and cardiac function in workers of the Esfahan Steel Industry, Iran.

    Science.gov (United States)

    Golshahi, Jafar; Sadeghi, Masoumeh; Saqira, Mohammad; Zavar, Reihaneh; Sadeghifar, Mostafa; Roohafza, Hamidreza

    2016-06-01

    Air pollution is recognized as an important risk factor for cardiovascular disease. We investigated association of exposure to occupational air pollution and cardiac function in the workers of the steel industry. Fifty male workers of the agglomeration and coke-making parts of the Esfahan Steel Company were randomly selected (n = 50). Workers in the administrative parts were studied as controls (n = 50). Those with known history of hypertension, dyslipidemia, or diabetes, and active smokers were not included. Data of age, body mass index, employment duration, blood pressure, fasting blood sugar, and lipid profile were gathered. Echocardiography was performed to evaluate cardiac function. Left ventricular ejection fraction was lower in workers of the agglomeration/coke-making parts than in controls (mean difference = 5 to 5.5 %, P steel industry is associated with left heart systolic dysfunction. Possible right heart insults due to air pollution exposure warrant further investigations.

  14. Estimating pediatric general anesthesia exposure: Quantifying duration and risk.

    Science.gov (United States)

    Bartels, Devan Darby; McCann, Mary Ellen; Davidson, Andrew J; Polaner, David M; Whitlock, Elizabeth L; Bateman, Brian T

    2018-05-02

    Understanding the duration of pediatric general anesthesia exposure in contemporary practice is important for identifying groups at risk for long general anesthesia exposures and designing trials examining associations between general anesthesia exposure and neurodevelopmental outcomes. We performed a retrospective cohort analysis to estimate pediatric general anesthesia exposure duration during 2010-2015 using the National Anesthesia Clinical Outcomes Registry. A total of 1 548 021 pediatric general anesthetics were included. Median general anesthesia duration was 57 minutes (IQR: 28-86) with 90th percentile 145 minutes. Children aged 3 hours. High ASA physical status and care at a university hospital were associated with longer exposure times. While the vast majority (94%) of children undergoing general anesthesia are exposed for risk for longer exposures. These findings may help guide the design of future trials aimed at understanding neurodevelopmental impact of prolonged exposure in these high-risk groups. © 2018 John Wiley & Sons Ltd.

  15. Fetal motion estimation from noninvasive cardiac signal recordings.

    Science.gov (United States)

    Biglari, Hadis; Sameni, Reza

    2016-11-01

    Fetal motility is a widely accepted indicator of the well-being of a fetus. In previous research, it has be shown that fetal motion (FM) is coherent with fetal heart rate accelerations and an indicator for active/rest cycles of the fetus. The most common approach for FM and fetal heart rate (FHR) assessment is by Doppler ultrasound (DUS). While DUS is the most common approach for studying the mechanical activities of the heart, noninvasive fetal electrocardiogram (ECG) and magnetocardiogram (MCG) recording and processing techniques have been considered as a possible competitor (or complement) for the DUS. In this study, a fully automatic and robust framework is proposed for the extraction, ranking and alignment of fetal QRS-complexes from noninvasive fetal ECG/MCG. Using notions from subspace tracking, two measures, namely the actogram and rotatogram, are defined for fetal motion tracking. The method is applied to four fetal ECG/MCG databases, including twin MCG recordings. By defining a novel measure of causality, it is shown that there is significant coherency and causal relationship between the actogram/rotatogram and FHR accelerations/decelerations. Using this measure, it is shown that in many cases, the actogram and rotatogram precede the FHR variations, which supports the idea of motion-induced FHR accelerations/decelerations for these cases and raises attention for the non-motion-induced FHR variations, which can be associated to the fetal central nervous system developments. The results of this study can lead to novel perspectives of the fetal sympathetic and parasympathetic brain systems and future requirements of fetal cardiac monitoring.

  16. Estimation of the patient exposure in tomography

    International Nuclear Information System (INIS)

    Maekoshi, Hisashi; Orito, Takeo; Nishizawa, Kunihide; Koga, Sukehiko.

    1975-01-01

    The author evaluated the estimation method of radiation dose according to surface and intracorporeal dose distribution in chest-tomography. In the study with phantom it was found that the maximum dose area of the skin surface became small and variation of dose in the surrounding area was sharp in proportion to the depth of the cross section. Therefore the author considers that the skin surface dose in tomography should be represented by the highest skin surface dose. In the intracorporeal distribution, the circular tomography undertaken at 10 cm deep from the surface indicated a larger equivalent dose area and higher yielding rate than those in curvilinear tomography. When the phantom filled with water and the one filled with lung equivalent material, cork, were compared; the radiation dose around the radiation field in the phantom with cork was 2-2.5 times the other in circular tomography. However, if the distance from the radiation field became as far as 40 cm, the cork of phantom made little difference. If the radiation dose on the cross section is estimated as 100% in drawing the intracorporeal dose distribution, the results change depending on lung equivalent material. Therefore the author considers that the highest skin dose will be more universal to be taken as the standard. (Kanao, N.)

  17. Biomass fuel smoke exposure was associated with adverse cardiac remodeling and left ventricular dysfunction in Peru.

    Science.gov (United States)

    Burroughs Peña, M S; Velazquez, E J; Rivera, J D; Alenezi, F; Wong, C; Grigsby, M; Davila-Roman, V G; Gilman, R H; Miranda, J J; Checkley, W

    2017-07-01

    While household air pollution from biomass fuel combustion has been linked to cardiovascular disease, the effects on cardiac structure and function have not been well described. We sought to determine the association between biomass fuel smoke exposure and cardiac structure and function by transthoracic echocardiography. We identified a random sample of urban and rural residents living in the high-altitude region of Puno, Peru. Daily biomass fuel use was self-reported. Participants underwent transthoracic echocardiography. Multivariable linear regression was used to examine the relationship of biomass fuel use with echocardiographic measures of cardiac structure and function, adjusting for age, sex, height, body mass index, diabetes, physical activity, and tobacco use. One hundred and eighty-seven participants (80 biomass fuel users and 107 non-users) were included in this analysis (mean age 59 years, 58% women). After adjustment, daily exposure to biomass fuel smoke was associated with increased left ventricular internal diastolic diameter (P=.004), left atrial diameter (P=.03), left atrial area (four-chamber) (P=.004) and (two-chamber) (P=.03), septal E' (P=.006), and lateral E' (P=.04). Exposure to biomass fuel smoke was also associated with worse global longitudinal strain in the two-chamber view (P=.01). Daily biomass fuel use was associated with increased left ventricular size and decreased left ventricular systolic function by global longitudinal strain. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Direct and simultaneous estimation of cardiac four chamber volumes by multioutput sparse regression.

    Science.gov (United States)

    Zhen, Xiantong; Zhang, Heye; Islam, Ali; Bhaduri, Mousumi; Chan, Ian; Li, Shuo

    2017-02-01

    Cardiac four-chamber volume estimation serves as a fundamental and crucial role in clinical quantitative analysis of whole heart functions. It is a challenging task due to the huge complexity of the four chambers including great appearance variations, huge shape deformation and interference between chambers. Direct estimation has recently emerged as an effective and convenient tool for cardiac ventricular volume estimation. However, existing direct estimation methods were specifically developed for one single ventricle, i.e., left ventricle (LV), or bi-ventricles; they can not be directly used for four chamber volume estimation due to the great combinatorial variability and highly complex anatomical interdependency of the four chambers. In this paper, we propose a new, general framework for direct and simultaneous four chamber volume estimation. We have addressed two key issues, i.e., cardiac image representation and simultaneous four chamber volume estimation, which enables accurate and efficient four-chamber volume estimation. We generate compact and discriminative image representations by supervised descriptor learning (SDL) which can remove irrelevant information and extract discriminative features. We propose direct and simultaneous four-chamber volume estimation by the multioutput sparse latent regression (MSLR), which enables jointly modeling nonlinear input-output relationships and capturing four-chamber interdependence. The proposed method is highly generalized, independent of imaging modalities, which provides a general regression framework that can be extensively used for clinical data prediction to achieve automated diagnosis. Experiments on both MR and CT images show that our method achieves high performance with a correlation coefficient of up to 0.921 with ground truth obtained manually by human experts, which is clinically significant and enables more accurate, convenient and comprehensive assessment of cardiac functions. Copyright © 2016 Elsevier

  19. Strategies for estimating human exposure to mycotoxins via food

    NARCIS (Netherlands)

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

    2016-01-01

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

  20. Forest Fire Smoke Exposures and Out-of-Hospital Cardiac Arrests in Melbourne, Australia: A Case-Crossover Study.

    Science.gov (United States)

    Dennekamp, Martine; Straney, Lahn D; Erbas, Bircan; Abramson, Michael J; Keywood, Melita; Smith, Karen; Sim, Malcolm R; Glass, Deborah C; Del Monaco, Anthony; Haikerwal, Anjali; Tonkin, Andrew M

    2015-10-01

    Millions of people can potentially be exposed to smoke from forest fires, making this an important public health problem in many countries. In this study we aimed to measure the association between out-of-hospital cardiac arrest (OHCA) and forest fire smoke exposures in a large city during a severe forest fire season, and estimate the number of excess OHCAs due to the fire smoke. We investigated the association between particulate matter (PM) and other air pollutants and OHCA using a case-crossover study of adults (≥ 35 years of age) in Melbourne, Australia. Conditional logistic regression models were used to derive estimates of the percent change in the rate of OHCA associated with an interquartile range (IQR) increase in exposure. From July 2006 through June 2007, OHCA data were collected from the Victorian Ambulance Cardiac Arrest Registry. Hourly air pollution concentrations and meteorological data were obtained from a central monitoring site. There were 2,046 OHCAs with presumed cardiac etiology during our study period. Among men during the fire season, greater increases in OHCA were observed with IQR increases in the 48-hr lagged PM with diameter ≤ 2.5 μm (PM2.5) (8.05%; 95% CI: 2.30, 14.13%; IQR = 6.1 μg/m(3)) or ≤ 10 μm (PM10) (11.1%; 95% CI: 1.55, 21.48%; IQR = 13.7 μg/m(3)) and carbon monoxide (35.7%; 95% CI: 8.98, 68.92%; IQR = 0.3 ppm). There was no significant association between the rate of OHCA and air pollutants among women. One hundred seventy-four "fire-hours" (i.e., hours in which Melbourne's air quality was affected by forest fire smoke) were identified during 12 days of the 2006/2007 fire season, and 23.9 (95% CI: 3.1, 40.2) excess OHCAs were estimated to occur due to elevations in PM2.5 during these fire-hours. This study found an association between exposure to forest fire smoke and an increase in the rate of OHCA. These findings have implications for public health messages to raise community awareness and for planning of emergency

  1. Non-sedating antihistamine drugs and cardiac arrhythmias -- biased risk estimates from spontaneous reporting systems?

    DEFF Research Database (Denmark)

    De Bruin, M L; van Puijenbroek, E P; Egberts, A C G

    2002-01-01

    of these drugs. METHODS: All suspected adverse drug reactions (ADRs) reported until July 1999 to the Netherlands Pharmacovigilance Foundation Lareb were used to calculate the ADR reporting odds ratio, defined as the ratio of exposure odds among reported arrhythmia cases, to the exposure odds of other ADRs (non......-sedating antihistamines. In general non-sedating antihistamines are associated with cardiac arrhythmia to a higher extent in comparison with other drugs (ADR reporting odds ratio 2.05 [95% CI: 1.45, 2.89]). The association between arrhythmias and non-sedating antihistamine drugs calculated before 1998...

  2. Design-based stereological estimation of the total number of cardiac myocytes in histological sections

    DEFF Research Database (Denmark)

    Brüel, Annemarie; Nyengaard, Jens Randel

    2005-01-01

    in LM sections using design-based stereology. MATERIALS AND METHODS: From formalin-fixed left rat ventricles (LV) isotropic uniformly random sections were cut. The total number of myocyte nuclei per LV was estimated using the optical disector. Two-microm-thick serial paraffin sections were stained......BACKGROUND: Counting the total number of cardiac myocytes has not previously been possible in ordinary histological sections using light microscopy (LM) due to difficulties in defining the myocyte borders properly. AIM: To describe a method by which the total number of cardiac myocytes is estimated...... with antibodies against cadherin and type IV collagen to visualise the intercalated discs and the myocyte membranes, respectively. Using the physical disector in "local vertical windows" of the serial sections, the average number of nuclei per myocyte was estimated.RESULTS: The total number of myocyte nuclei...

  3. Estimating changes in cardiac output using an implanted hemodynamic monitor in heart failure patients

    DEFF Research Database (Denmark)

    Ståhlberg, Marcus; Damgaard, Morten; Ersgård, David

    2010-01-01

    OBJECTIVES: The aim of this study was to evaluate an algorithm that estimates changes in cardiac output (CO) from right ventricular (RV) pressure waveforms derived from an implantable hemodynamic monitor (IHM) in heart failure patients. DESIGN: Twelve heart failure patients (NYHA II-III, EF 32......%) with an implantable hemodynamic monitor (Chronicle) were included in this study. Changes in cardiac output were provoked by body position change at rest (left lateral supine, horizontal supine, sitting, and standing) and a steady state bicycle exercise at 20 watts. Estimated CO derived from the IHM (CO...... was -0.39 L/min (11%). Limits of agreement were +/-1.56 L/min and relative error was 21%. CONCLUSIONS: A simple algorithm based on RV pressure wave form characteristics derived from an IHM can be used to estimate changes in CO in heart failure patients. These findings encourage further research aiming...

  4. Perinatal DDT Exposure Induces Hypertension and Cardiac Hypertrophy in Adult Mice.

    Science.gov (United States)

    La Merrill, Michele A; Sethi, Sunjay; Benard, Ludovic; Moshier, Erin; Haraldsson, Borje; Buettner, Christoph

    2016-11-01

    Dichlorodiphenyltrichloroethane (DDT) was used extensively to control malaria, typhus, body lice, and bubonic plague worldwide, until countries began restricting its use in the 1970s. However, the use of DDT to control vector-borne diseases continues in developing countries. Prenatal DDT exposure is associated with elevated blood pressure in humans. We hypothesized that perinatal DDT exposure causes hypertension in adult mice. DDT was administered to C57BL/6J dams from gestational day 11.5 to postnatal day 5. Blood pressure (BP) and myocardial wall thickness were measured in male and female adult offspring. Adult mice were treated with an angiotensin converting enzyme (ACE) inhibitor, captopril, to evaluate sensitivity to amelioration of DDT-associated hypertension by ACE inhibition. We further assessed the influence of DDT exposure on the expression of mRNAs that regulate BP through renal ion transport. Adult mice perinatally exposed to DDT exhibited chronically increased systolic BP, increased myocardial wall thickness, and elevated expression of mRNAs of several renal ion transporters. Captopril completely reversed hypertension in mice perinatally exposed to DDT. These data demonstrate that perinatal exposure to DDT causes hypertension and cardiac hypertrophy in adult offspring. A key mechanism underpinning this hypertension is an overactivated renin angiotensin system because ACE inhibition reverses the hypertension induced by perinatal DDT exposure. Citation: La Merrill M, Sethi S, Benard L, Moshier E, Haraldsson B, Buettner C. 2016. Perinatal DDT exposure induces hypertension and cardiac hypertrophy in adult mice. Environ Health Perspect 124:1722-1727; http://dx.doi.org/10.1289/EHP164.

  5. Recurrent exposure to subclinical lipopolysaccharide increases mortality and induces cardiac fibrosis in mice.

    Directory of Open Access Journals (Sweden)

    Wilbur Y W Lew

    Full Text Available BACKGROUND: Circulating subclinical lipopolysaccharide (LPS occurs in health and disease. Ingesting high fatty meals increases LPS that cause metabolic endotoxemia. Subclinical LPS in periodontal disease may impair endothelial function. The heart may be targeted as cardiac cells express TLR4, the LPS receptor. It was hypothesized that recurrent exposure to subclinical LPS increases mortality and causes cardiac fibrosis. METHODS: C57Bl/6 mice were injected with intraperitoneal saline (control, low dose LPS (0.1 or 1 mg/kg, or moderate dose LPS (10 or 20 mg/kg, once a week for 3 months. Left ventricular (LV function (echocardiography, hemodynamics (tail cuff pressure and electrocardiograms (telemetry were measured. Cardiac fibrosis was assessed by picrosirius red staining and LV expression of fibrosis related genes (QRT-PCR. Adult cardiac fibroblasts were isolated and exposed to LPS. RESULTS: LPS injections transiently increased heart rate and blood pressure (<6 hours and mildly decreased LV function with full recovery by 24 hours. Mice tolerated weekly LPS for 2-3 months with no change in activity, appearance, appetite, weight, blood pressure, LV function, oximetry, or blood chemistries. Mortality increased after 60-90 days with moderate, but not low dose LPS. Arrhythmias occurred a few hours before death. LV collagen fraction area increased dose-dependently from 3.0±0.5% (SEM in the saline control group, to 5.6±0.5% with low dose LPS and 9.7±0.9% with moderate dose LPS (P<0.05 moderate vs low dose LPS, and each LPS dose vs control. LPS increased LV expression of collagen Iα1, collagen IIIα1, MMP2, MMP9, TIMP1, periostin and IL-6 (P<0.05 moderate vs low dose LPS and vs control. LPS increased α-SMA immunostaining of myofibroblasts. LPS dose-dependently increased IL-6 in isolated adult cardiac fibroblasts. CONCLUSIONS: Recurrent exposure to subclinical LPS increases mortality and induces cardiac fibrosis.

  6. Operator dependency of the radiation exposure in cardiac interventions: feasibility of ultra low dose levels

    International Nuclear Information System (INIS)

    Emre Ozpelit, Mehmet; Ercan, Ertugrul; Pekel, Nihat; Tengiz, Istemihan; Yilmaz, Akar; Ozpelit, Ebru; Ozyurtlu, Ferhat

    2017-01-01

    Introduction: Mean radiation exposure in invasive cardiology varies greatly between different centres and interventionists. The International Commission on Radiological Protection and the EURATOM Council stipulate that, despite reference values, 'All medical exposure for radiodiagnostic purposes shall be kept as low as reasonably achievable' (ALARA). The purpose of this study is to establish the effects of the routine application of ALARA principles and to determine operator and procedure impact on radiation exposure in interventional cardiology. Materials and methods: A total of 240 consecutive cardiac interventional procedures were analysed. Five operators performed the procedures, two of whom were working in accordance with ALARA principles (Group 1 operators) with the remaining three working in a standard manner (Group 2 operators). Radiation exposure levels of these two groups were compared. Results: Total fluoroscopy time and the number of radiographic runs were similar between groups. However, dose area product and cumulative dose were significantly lower in Group 1 when compared with Group 2. Radiation levels of Group 1 were far below even the reference levels in the literature, thus representing an ultra-low-dose radiation exposure in interventional cardiology. Conclusion: By use of simple radiation reducing techniques, ultra-low-dose radiation exposure is feasible in interventional cardiology. Achievability of such levels depends greatly on operator awareness, desire, knowledge and experience of radiation protection. (authors)

  7. Estimating the burden of disease attributable to lead exposure in ...

    African Journals Online (AJOL)

    Objectives. To estimate the burden of disease attributable to lead exposure in South Africa in 2000. Design. World Health Organization comparative risk assessment (CRA) methodology was followed. Recent community studies were used to derive mean blood lead concentrations in adults and children in urban and rural ...

  8. [Cardiac Synchronization Function Estimation Based on ASM Level Set Segmentation Method].

    Science.gov (United States)

    Zhang, Yaonan; Gao, Yuan; Tang, Liang; He, Ying; Zhang, Huie

    At present, there is no accurate and quantitative methods for the determination of cardiac mechanical synchronism, and quantitative determination of the synchronization function of the four cardiac cavities with medical images has a great clinical value. This paper uses the whole heart ultrasound image sequence, and segments the left & right atriums and left & right ventricles of each frame. After the segmentation, the number of pixels in each cavity and in each frame is recorded, and the areas of the four cavities of the image sequence are therefore obtained. The area change curves of the four cavities are further extracted, and the synchronous information of the four cavities is obtained. Because of the low SNR of Ultrasound images, the boundary lines of cardiac cavities are vague, so the extraction of cardiac contours is still a challenging problem. Therefore, the ASM model information is added to the traditional level set method to force the curve evolution process. According to the experimental results, the improved method improves the accuracy of the segmentation. Furthermore, based on the ventricular segmentation, the right and left ventricular systolic functions are evaluated, mainly according to the area changes. The synchronization of the four cavities of the heart is estimated based on the area changes and the volume changes.

  9. Radiation exposure of an anaesthesiologist in catheterisation and electrophysiological cardiac procedures

    International Nuclear Information System (INIS)

    Andreoli, Stefano; Moretti, Renzo; Lorini, Ferdinando Luca; Lagrotta, Mariavittoria

    2016-01-01

    Sometimes, cardiac catheterisation and electrophysiological procedures, diagnostic and interventional, require an anaesthesiological support. The anaesthesiologist receives radiation doses depending on various factors, such as type of procedure and exposure modality, anaesthesiological technique, individual protective devices and operator experience. The aim of this study was to investigate the dose per procedure, the exposure inhomogeneity and the effective dose, E, of a senior anaesthesiologist in the haemodynamic laboratory of Ospedali Riuniti, Bergamo. The dose monitoring was routinely performed with sets of several thermoluminescent dosemeters and an electronic personal dosemeter. The study covered 300 consecutive procedures over 1 y. The anaesthesiologist wore a protective apron, a thyroid collar and glasses (0.5 mm lead-equivalent). (authors)

  10. Evaluation of cumulative PCB exposure estimated by a job exposure matrix versus PCB serum concentrations

    Science.gov (United States)

    Ruder, Avima M.; Succop, Paul; Waters, Martha A.

    2015-01-01

    Although polychlorinated biphenyls (PCBs) have been banned in many countries for more than three decades, exposures to PCBs continue to be of concern due to their long half-lives and carcinogenic effects. In National Institute for Occupational Safety and Health studies, we are using semiquantitative plant-specific job exposure matrices (JEMs) to estimate historical PCB exposures for workers (n=24,865) exposed to PCBs from 1938 to 1978 at three capacitor manufacturing plants. A subcohort of these workers (n=410) employed in two of these plants had serum PCB concentrations measured at up to four times between 1976 and 1989. Our objectives were to evaluate the strength of association between an individual worker’s measured serum PCB levels and the same worker’s cumulative exposure estimated through 1977 with the (1) JEM and (2) duration of employment, and to calculate the explained variance the JEM provides for serum PCB levels using (3) simple linear regression. Consistent strong and statistically significant associations were observed between the cumulative exposures estimated with the JEM and serum PCB concentrations for all years. The strength of association between duration of employment and serum PCBs was good for highly chlorinated (Aroclor 1254/HPCB) but not less chlorinated (Aroclor 1242/LPCB) PCBs. In the simple regression models, cumulative occupational exposure estimated using the JEMs explained 14–24 % of the variance of the Aroclor 1242/LPCB and 22–39 % for Aroclor 1254/HPCB serum concentrations. We regard the cumulative exposure estimated with the JEM as a better estimate of PCB body burdens than serum concentrations quantified as Aroclor 1242/LPCB and Aroclor 1254/HPCB. PMID:23475397

  11. Cardiac dose estimates from Danish and Swedish breast cancer radiotherapy during 1977-2001

    International Nuclear Information System (INIS)

    Taylor, Carolyn W.; Bronnum, Dorthe; Darby, Sarah C.; Gagliardi, Giovanna; Hall, Per; Jensen, Maj-Britt; McGale, Paul; Nisbet, Andrew; Ewertz, Marianne

    2011-01-01

    Background and purpose: To estimate target and cardiac doses from breast cancer radiotherapy in Denmark and in the Stockholm and Umea areas of Sweden during 1977-2001. Methods: Representative samples of irradiated women were identified from the databases of the Danish Breast Cancer Cooperative Group and the Swedish Nationwide Cancer Registry. Virtual simulation, computed tomography planning and manual planning were used to reconstruct radiotherapy regimens on a typical woman. Estimates of target dose and various measures of cardiac dose were derived from individual radiotherapy charts. Results: Doses were estimated in 681 Danish and 130 Swedish women. Mean heart dose for individual women varied from 1.6 to 14.9 Gray in Denmark and from 1.2 to 22.1 Gray in Sweden. In Denmark, mean target doses averaged across women increased from 40.6 to 53.8 Gray during 1977-2001 but, despite this, mean heart dose averaged across women remained around 6 Gy for left-sided and 2-3 Gray for right-sided radiotherapy. In Sweden mean target dose averaged across women increased from 38.7 to 46.6 Gray during 1977-2001, while mean heart dose averaged across women decreased from 12.0 to 7.3 Gray for left-sided and from 3.6 to 3.2 Gray for right-sided radiotherapy. Temporal trends for mean biologically effective dose [BED] to the heart, mean dose to the left anterior descending coronary artery, the right coronary artery and the circumflex coronary artery were broadly similar. Conclusions: Cardiac doses in Denmark were low relative to those in Sweden. In both countries, target dose increased during 1977-2001. Despite this, cardiac doses remained constant in Denmark and decreased in Sweden.

  12. Radiation exposure estimation from patient treated by I-131

    International Nuclear Information System (INIS)

    Lahfi, Y.; Anjak, O.

    2012-09-01

    Radioactive iodine is the main radiopharmaceutical substance in the nuclear medicine field which used in diagnosis and treatment of patients suffering from thyroid cancer; thus it can be considered as the main source of the public and patient relative exposure. In this study, 192 patients were selected randomly and their radiation dose rate was measured at different levels of the patient's body (thyroid, knee, bladder) after one, twenty four and forty eight hours from availing the prescript quantity of the I-131. The collected data may serve in estimating the worker and public exposure related to the patient treated by I-131. (authors)

  13. Stochastic precision analysis of 2D cardiac strain estimation in vivo

    International Nuclear Information System (INIS)

    Bunting, E A; Provost, J; Konofagou, E E

    2014-01-01

    Ultrasonic strain imaging has been applied to echocardiography and carries great potential to be used as a tool in the clinical setting. Two-dimensional (2D) strain estimation may be useful when studying the heart due to the complex, 3D deformation of the cardiac tissue. Increasing the framerate used for motion estimation, i.e. motion estimation rate (MER), has been shown to improve the precision of the strain estimation, although maintaining the spatial resolution necessary to view the entire heart structure in a single heartbeat remains challenging at high MERs. Two previously developed methods, the temporally unequispaced acquisition sequence (TUAS) and the diverging beam sequence (DBS), have been used in the past to successfully estimate in vivo axial strain at high MERs without compromising spatial resolution. In this study, a stochastic assessment of 2D strain estimation precision is performed in vivo for both sequences at varying MERs (65, 272, 544, 815 Hz for TUAS; 250, 500, 1000, 2000 Hz for DBS). 2D incremental strains were estimated during left ventricular contraction in five healthy volunteers using a normalized cross-correlation function and a least-squares strain estimator. Both sequences were shown capable of estimating 2D incremental strains in vivo. The conditional expected value of the elastographic signal-to-noise ratio (E(SNRe|ε)) was used to compare strain estimation precision of both sequences at multiple MERs over a wide range of clinical strain values. The results here indicate that axial strain estimation precision is much more dependent on MER than lateral strain estimation, while lateral estimation is more affected by strain magnitude. MER should be increased at least above 544 Hz to avoid suboptimal axial strain estimation. Radial and circumferential strain estimations were influenced by the axial and lateral strain in different ways. Furthermore, the TUAS and DBS were found to be of comparable precision at similar MERs. (paper)

  14. Cardiac Exposure in the Dynamic Conformal Arc Therapy, Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy of Lung Cancer.

    Directory of Open Access Journals (Sweden)

    Xin Ming

    Full Text Available To retrospectively evaluate the cardiac exposure in three cohorts of lung cancer patients treated with dynamic conformal arc therapy (DCAT, intensity-modulated radiotherapy (IMRT, or volumetric modulated arc therapy (VMAT at our institution in the past seven years.A total of 140 lung cancer patients were included in this institutional review board approved study: 25 treated with DCAT, 70 with IMRT and 45 with VMAT. All plans were generated in a same commercial treatment planning system and have been clinically accepted and delivered. The dose distribution to the heart and the effects of tumor laterality, the irradiated heart volume and the beam-to-heart distance on the cardiac exposure were investigated.The mean dose to the heart among all 140 plans was 4.5 Gy. Specifically, the heart received on average 2.3, 5.2 and 4.6 Gy in the DCAT, IMRT and VMAT plans, respectively. The mean heart doses for the left and right lung tumors were 4.1 and 4.8 Gy, respectively. No patients died with evidence of cardiac disease. Three patients (2% with preexisting cardiac condition developed cardiac disease after treatment. Furthermore, the cardiac exposure was found to increase linearly with the irradiated heart volume while decreasing exponentially with the beam-to-heart distance.Compared to old technologies for lung cancer treatment, modern radiotherapy treatment modalities demonstrated better heart sparing. But the heart dose in lung cancer radiotherapy is still higher than that in the radiotherapy of breast cancer and Hodgkin's disease where cardiac complications have been extensively studied. With strong correlations of mean heart dose with beam-to-heart distance and irradiated heart volume, cautions should be exercised to avoid long-term cardiac toxicity in the lung cancer patients undergoing radiotherapy.

  15. Anatomic features of interest in women at risk of cardiac exposure from whole breast radiotherapy

    International Nuclear Information System (INIS)

    Lee, Grace; Rosewall, Tara; Fyles, Anthony; Harnett, Nicole; Dinniwell, Robert E.

    2015-01-01

    Background and purpose: Left-sided breast radiotherapy (RT) can result in cardiac exposure. This study aims to identify predictive anatomic features in women requiring breath-hold (RT BH ) for cardiac sparing during adjuvant whole breast RT. Material and methods: We retrospectively reviewed free-breathing (FB) CT scans of 80 women previously treated with left-sided breast RT. Unfavourable cardiac anatomy was defined as the number of consecutive axial CT slices (2 mm) in which the anterior chest wall contacted the heart (Contact Heart ) or left ventricle (Contact LV ). The sternal angle and Haller Index (HI) were used to measure chest concavity. Position and volume of post-operative cavity was also quantified. Results: Heart mean dose (D mean ) was strongly correlated with Contact LV (r = 0.625, p < 0.001) and Contact Heart (r = 0.524, p < 0.001) but not significantly correlated with tumor size, cavity volume, heart volume, cavity distance to chest wall, sternal angle, or HI. ROC analysis of Contact Heart was most predictive of the need for breath-hold (RT BH ) technique [Area Under Curve = 0.815 (SE: 0.048; 95% CI: 0.721–0.91)] and ⩾25 Contact Heart CT slices predicted for heart D mean ⩾1.7 Gy (68% sensitivity and 82% specificity). Conclusion: Contact Heart on FB CT of ⩾25 axial slices (2 mm), ⩾50 mm of para-sagittal heart contact, was predictive of higher heart D mean and suggest a potential need for RT BH

  16. Methods of estimation of mitral valve regurgitation for the cardiac surgeon

    Directory of Open Access Journals (Sweden)

    Baikoussis Nikolaos G

    2009-07-01

    Full Text Available Abstract Mitral valve regurgitation is a relatively common and important heart valve lesion in clinical practice and adequate assessment is fundamental to decision on management, repair or replacement. Disease localised to the posterior mitral valve leaflet or focal involvement of the anterior mitral valve leaflet is most amenable to mitral valve repair, whereas patients with extensive involvement of the anterior leaflet or incomplete closure of the valve are more suitable for valve replacement. Echocardiography is the recognized investigation of choice for heart valve disease evaluation and assessment. However, the technique is depended on operator experience and on patient's hemodynamic profile, and may not always give optimal diagnostic views of mitral valve dysfunction. Cardiac catheterization is related to common complications of an interventional procedure and needs a hemodynamic laboratory. Cardiac magnetic resonance (MRI seems to be a useful tool which gives details about mitral valve anatomy, precise point of valve damage, as well as the quantity of regurgitation. Finally, despite of its higher cost, cardiac MRI using cine images with optimized spatial and temporal resolution can also resolve mitral valve leaflet structural motion, and can reliably estimate the grade of regurgitation.

  17. Estimated glomerular filtration rate is an early biomarker of cardiac surgery-associated acute kidney injury.

    Science.gov (United States)

    Candela-Toha, Ángel; Pardo, María Carmen; Pérez, Teresa; Muriel, Alfonso; Zamora, Javier

    2018-04-20

    and objective Acute kidney injury (AKI) diagnosis is still based on serum creatinine and diuresis. However, increases in creatinine are typically delayed 48h or longer after injury. Our aim was to determine the utility of routine postoperative renal function blood tests, to predict AKI one or 2days in advance in a cohort of cardiac surgery patients. Using a prospective database, we selected a sample of patients who had undergone major cardiac surgery between January 2002 and December 2013. The ability of the parameters to predict AKI was based on Acute Kidney Injury Network serum creatinine criteria. A cohort of 3,962 cases was divided into 2groups of similar size, one being exploratory and the other a validation sample. The exploratory group was used to show primary objectives and the validation group to confirm results. The ability to predict AKI of several kidney function parameters measured in routine postoperative blood tests, was measured with time-dependent ROC curves. The primary endpoint was time from measurement to AKI diagnosis. AKI developed in 610 (30.8%) and 623 (31.4%) patients in the exploratory and validation samples, respectively. Estimated glomerular filtration rate using the MDRD-4 equation showed the best AKI prediction capacity, with values for the AUC ROC curves between 0.700 and 0.946. We obtained different cut-off values for estimated glomerular filtration rate depending on the degree of AKI severity and on the time elapsed between surgery and parameter measurement. Results were confirmed in the validation sample. Postoperative estimated glomerular filtration rate using the MDRD-4 equation showed good ability to predict AKI following cardiac surgery one or 2days in advance. Copyright © 2018 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  18. Estimation of 3-D conduction velocity vector fields from cardiac mapping data.

    Science.gov (United States)

    Barnette, A R; Bayly, P V; Zhang, S; Walcott, G P; Ideker, R E; Smith, W M

    2000-08-01

    A method to estimate three-dimensional (3-D) conduction velocity vector fields in cardiac tissue is presented. The speed and direction of propagation are found from polynomial "surfaces" fitted to space-time (x, y, z, t) coordinates of cardiac activity. The technique is applied to sinus rhythm and paced rhythm mapped with plunge needles at 396-466 sites in the canine myocardium. The method was validated on simulated 3-D plane and spherical waves. For simulated data, conduction velocities were estimated with an accuracy of 1%-2%. In experimental data, estimates of conduction speeds during paced rhythm were slower than those found during normal sinus rhythm. Vector directions were also found to differ between different types of beats. The technique was able to distinguish between premature ventricular contractions and sinus beats and between sinus and paced beats. The proposed approach to computing velocity vector fields provides an automated, physiological, and quantitative description of local electrical activity in 3-D tissue. This method may provide insight into abnormal conduction associated with fatal ventricular arrhythmias.

  19. Motion estimation for cardiac functional analysis using two x-ray computed tomography scans.

    Science.gov (United States)

    Fung, George S K; Ciuffo, Luisa; Ashikaga, Hiroshi; Taguchi, Katsuyuki

    2017-09-01

    This work concerns computed tomography (CT)-based cardiac functional analysis (CFA) with a reduced radiation dose. As CT-CFA requires images over the entire heartbeat, the scans are often performed at 10-20% of the tube current settings that are typically used for coronary CT angiography. A large image noise then degrades the accuracy of motion estimation. Moreover, even if the scan was performed during the sinus rhythm, the cardiac motion observed in CT images may not be cyclic with patients with atrial fibrillation. In this study, we propose to use two CT scan data, one for CT angiography at a quiescent phase at a standard dose and the other for CFA over the entire heart beat at a lower dose. We have made the following four modifications to an image-based cardiac motion estimation method we have previously developed for a full-dose retrospectively gated coronary CT angiography: (a) a full-dose prospectively gated coronary CT angiography image acquired at the least motion phase was used as the reference image; (b) a three-dimensional median filter was applied to lower-dose retrospectively gated cardiac images acquired at 20 phases over one heartbeat in order to reduce image noise; (c) the strength of the temporal regularization term was made adaptive; and (d) a one-dimensional temporal filter was applied to the estimated motion vector field in order to decrease jaggy motion patterns. We describe the conventional method iME1 and the proposed method iME2 in this article. Five observers assessed the accuracy of the estimated motion vector field of iME2 and iME1 using a 4-point scale. The observers repeated the assessment with data presented in a new random order 1 week after the first assessment session. The study confirmed that the proposed iME2 was robust against the mismatch of noise levels, contrast enhancement levels, and shapes of the chambers. There was a statistically significant difference between iME2 and iME1 (accuracy score, 2.08 ± 0.81 versus 2.77

  20. Radiation Exposure Decreases the Quantity and Quality of Cardiac Stem Cells in Mice

    Science.gov (United States)

    Luo, Lan; Urata, Yoshishige; Yan, Chen; Hasan, Al Shaimaa; Goto, Shinji; Guo, Chang-Ying; Tou, Fang-Fang; Xie, Yucai; Li, Tao-Sheng

    2016-01-01

    Radiation exposure may increase cardiovascular disease risks; however, the precise molecular/cellular mechanisms remain unclear. In the present study, we examined the hypothesis that radiation impairs cardiac stem cells (CSCs), thereby contributing to future cardiovascular disease risks. Adult C57BL/6 mice were exposed to 3 Gy γ-rays, and heart tissues were collected 24 hours later for further experiments. Although c-kit-positive cells were rarely found, radiation exposure significantly induced apoptosis and DNA damage in the cells of the heart. The ex vivo expansion of CSCs from freshly harvested atrial tissues showed a significantly lower production of CSCs in irradiated mice compared with healthy mice. The proliferative activity of CSCs evaluated by Ki-67 expression was not significantly different between the groups. However, compared to the healthy control, CSCs expanded from irradiated mice showed significantly lower telomerase activity, more 53BP1 foci in the nuclei, lower expression of c-kit and higher expression of CD90. Furthermore, CSCs expanded from irradiated mice had significantly poorer potency in the production of insulin-like growth factor-1. Our data suggest that radiation exposure significantly decreases the quantity and quality of CSCs, which may serve as sensitive bio-parameters for predicting future cardiovascular disease risks. PMID:27195709

  1. Radiation Exposure Decreases the Quantity and Quality of Cardiac Stem Cells in Mice.

    Directory of Open Access Journals (Sweden)

    Lan Luo

    Full Text Available Radiation exposure may increase cardiovascular disease risks; however, the precise molecular/cellular mechanisms remain unclear. In the present study, we examined the hypothesis that radiation impairs cardiac stem cells (CSCs, thereby contributing to future cardiovascular disease risks. Adult C57BL/6 mice were exposed to 3 Gy γ-rays, and heart tissues were collected 24 hours later for further experiments. Although c-kit-positive cells were rarely found, radiation exposure significantly induced apoptosis and DNA damage in the cells of the heart. The ex vivo expansion of CSCs from freshly harvested atrial tissues showed a significantly lower production of CSCs in irradiated mice compared with healthy mice. The proliferative activity of CSCs evaluated by Ki-67 expression was not significantly different between the groups. However, compared to the healthy control, CSCs expanded from irradiated mice showed significantly lower telomerase activity, more 53BP1 foci in the nuclei, lower expression of c-kit and higher expression of CD90. Furthermore, CSCs expanded from irradiated mice had significantly poorer potency in the production of insulin-like growth factor-1. Our data suggest that radiation exposure significantly decreases the quantity and quality of CSCs, which may serve as sensitive bio-parameters for predicting future cardiovascular disease risks.

  2. Possible health hazards for cardiac pacemaker wearers from exposure to electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    1988-03-01

    Cardiac pacemakers are used to provide electrical stimulation to the heart when the heart's natural rhythm is interrupted. This study shows that they can be susceptible to electromagnetic fields. Pacemakers are well protected against common electromagnetic fields, such as those from household appliances. But intense electomagnetic fields, such as those found in some industrial settings, could affect the functioning of the pacemaker. Such interference may cause the pacemaker wearer to feel dizzy or experience an accelerated heartbeat. While this is not fatal, the pacemaker wearer should try to move away from the source of the interfering field and avoid situations in which interference could arise. After experiencing any of these symptoms, the pacemaker wearer should contact a physician. Potential sources of electromagnetic interference should be identified and characterized to determine if there could be an interference hazard. Exposure to interfering electomagnetic fields should be minimized. 7 refs., 1 fig.

  3. Disinfection By-Product Exposures and the Risk of Specific Cardiac Birth Defects

    Science.gov (United States)

    Wright, J. Michael; Evans, Amanda; Kaufman, John A.; Rivera-Núñez, Zorimar; Narotsky, Michael G.

    2016-01-01

    Background: Epidemiological studies suggest that women exposed to disinfection by-products (DBPs) have an increased risk of delivering babies with cardiovascular defects (CVDs). Objective: We examined nine CVDs in relation to categorical DBP exposures including bromoform, chloroform, dibromochloromethane (DBCM), bromodichloromethane (BDCM), monobromoacetic acid (MBAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and summary DBP measures (HAA5, THMBr, THM4, and DBP9). Methods: We calculated adjusted odds ratios (aORs) in a case–control study of birth defects in Massachusetts with complete quarterly 1999–2004 trihalomethane (THM) and haloacetic acid (HAA) data. We randomly matched 10 controls each to 904 CVD cases based on week of conception. Weight-averaged aggregate first-trimester DBP exposures were assigned to individuals based on residence at birth. Results: We detected associations for tetralogy of Fallot and the upper exposure categories for TCAA, DCAA, and HAA5 (aOR range, 3.34–6.51) including positive exposure–response relationships for DCAA and HAA5. aORs consistent in magnitude were detected between atrial septal defects and bromoform (aOR = 1.56; 95% CI: 1.01, 2.43), as well as DBCM, chloroform, and THM4 (aOR range, 1.26–1.67). Ventricular septal defects (VSDs) were associated with the highest bromoform (aOR = 1.85; 95% CI: 1.20, 2.83), MBAA (aOR = 1.81; 95% CI: 0.85, 3.84), and DBCM (aOR = 1.54; 95% CI: 1.00, 2.37) exposure categories. Conclusions: To our knowledge, this is the first birth defect study to develop multi-DBP adjusted regression models as well as the first CVD study to evaluate HAA exposures and the second to evaluate bromoform exposures. Our findings, therefore, inform exposure specificity for the consistent associations previously reported between THM4 and CVDs including VSDs. Citation: Wright JM, Evans A, Kaufman JA, Rivera-Núñez Z, Narotsky MG. 2017. Disinfection by-product exposures and the risk of specific

  4. Estimates of health risk from exposure to radioactive pollutants

    International Nuclear Information System (INIS)

    Sullivan, R.E.; Nelson, N.S.; Ellett, W.H.; Dunning, D.E. Jr.; Leggett, R.W.; Yalcintas, M.G.; Eckerman, K.F.

    1981-11-01

    A dosimetric and health effects analysis has been performed for the Office of Radiation Programs of the Environmental Protection Agency (EPA) to assess potential hazards from radioactive pollutants. Contemporary dosimetric methods were used to obtain estimates of dose rates to reference organs from internal exposures due to either inhalation of contaminated air or ingestion of contaminated food, or from external exposures due to either immersion in contaminated air or proximity to contaminated ground surfaces. These dose rates were then used to estimate the number of premature cancer deaths arising from such exposures and the corresponding number of years of life lost in a cohort of 100,000 persons, all simultaneously liveborn and all going through life with the same risks of dying from competing causes. The risk of dying from a competing cause for a given year was taken to be the probability of dying from all causes as given in a recent actuarial life table for the total US popula six times larger than the first reservoir.onunding. Analytical work cthe Department of Energy

  5. The Effect of Uncertainty in Exposure Estimation on the Exposure-Response Relation between 1,3-Butadiene and Leukemia

    Directory of Open Access Journals (Sweden)

    George Maldonado

    2009-09-01

    Full Text Available Abstract: In a follow-up study of mortality among North American synthetic rubber industry workers, cumulative exposure to 1,3-butadiene was positively associated with leukemia. Problems with historical exposure estimation, however, may have distorted the association. To evaluate the impact of potential inaccuracies in exposure estimation, we conducted uncertainty analyses of the relation between cumulative exposure to butadiene and leukemia. We created the 1,000 sets of butadiene estimates using job-exposure matrices consisting of exposure values that corresponded to randomly selected percentiles of the approximate probability distribution of plant-, work area/job group-, and year specific butadiene ppm. We then analyzed the relation between cumulative exposure to butadiene and leukemia for each of the 1,000 sets of butadiene estimates. In the uncertainty analysis, the point estimate of the RR for the first non zero exposure category (>0–<37.5 ppm-years was most likely to be about 1.5. The rate ratio for the second exposure category (37.5–<184.7 ppm-years was most likely to range from 1.5 to 1.8. The RR for category 3 of exposure (184.7–<425.0 ppm-years was most likely between 2.1 and 3.0. The RR for the highest exposure category (425.0+ ppm-years was likely to be between 2.9 and 3.7. This range off RR point estimates can best be interpreted as a probability distribution that describes our uncertainty in RR point estimates due to uncertainty in exposure estimation. After considering the complete probability distributions of butadiene exposure estimates, the exposure-response association of butadiene and leukemia was maintained. This exercise was a unique example of how uncertainty analyses can be used to investigate and support an observed measure of effect when occupational exposure estimates are employed in the absence of direct exposure measurements.

  6. Risk estimation of radiation exposure in early pregnancy

    International Nuclear Information System (INIS)

    Neumeister, K.; Waesser, S.

    1977-01-01

    The biomedical effects of radiation exposure (occupational, by X-ray diagnosis or examinations in nuclear medicine) to low doses on early pregnancy have been subject of a research work dealing with the dose level which, in case of exceeding, may lead to somatic damage (1.5 to 10 rem), and with the type of radiation injuries (malformations, functional disorder, cancer induction, increase in morbidity rate, genetic damage). A pilot study was the basis for the programme which will record such cases from all over the GDR. Within the scope of the health centre at the National Board of Nuclear Safety and Radiation Protection of the GDR, medical opinion on the interruption or preservation of pregnancy at its early stage, after exposure, was delivered in more than 50 cases. Exposure of the foetus was exactly determined. These children were re-investigated at the age of 1 to 3 years by applying pediatric and genetic examinations. The latter were based on clinical and biochemical methods as well as chromosome analyses. From these results, the risk of exposure in early pregnancy is estimated and adequate dose limits are suggested. In case these limits are exceeded, an interruption should be advised

  7. Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight

    NARCIS (Netherlands)

    Di Rienzo, Marco; Castiglioni, Paolo; Iellamo, Ferdinando; Volterrani, Maurizio; Pagani, Massimo; Mancia, Giuseppe; Karemaker, John M.; Parati, Gianfranco

    2008-01-01

    Di Rienzo M, Castiglioni P, Iellamo F, Volterrani M, Pagani M, Mancia G, Karemaker JM, Parati G. Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight. J Appl Physiol 105: 1569-1575, 2008. First published August 28, 2008;

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

    Science.gov (United States)

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

    2013-08-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  10. Personnel exposure estimates associated with nuclear fuel reprocessing waste

    International Nuclear Information System (INIS)

    Boone, F.W.; Rogers, B.W.

    1983-08-01

    The operation design of the Barnwell Nuclear Fuel Plant (BNFP) calls for shipment of its wastes to either a low-level waste disposal site or to a Federal repository. This study analyzes the probable radiation dose accrued to the personnel involved in handling waste packages from all identified waste streams of the BNFP from generation to reception at destination and including transportation. The shielding characteristics of the transport packages were derived by assuming packaging in existing or prototyped casks. Possible combinations of waste forms and packages for which the projected dose exceeded DOT or NRC regulations for transport of radioactive materials were rejected. Legal weight truck and legal weight rail transport modes were assumed. Potential ways for reducing overall personnel exposure are considered, concentrating on the particular streams with the largest dose contributions. The personnel exposure estimates were determined using a computer program specifically designed for this purpose. This program is described in Appendix A. 9 references, 3 figures, 19 tables

  11. Distinctive cardiac autonomic dysfunction following stress exposure in both sexes in an animal model of PTSD.

    Science.gov (United States)

    Koresh, Ori; Kaplan, Zeev; Zohar, Joseph; Matar, Michael A; Geva, Amir B; Cohen, Hagit

    2016-07-15

    It is unclear whether the poor autonomic flexibility or dysregulation observed in patients with posttraumatic stress disorder (PTSD) represents a pre-trauma vulnerability factor or results from exposure to trauma. We used an animal model of PTSD to assess the association between the behavioral response to predator scent stress (PSS) and the cardiac autonomic modulation in male and female rats. The rats were surgically implanted with radiotelemetry devices to measure their electrocardiograms and locomotor activity (LMA). Following baseline telemetric monitoring, the animals were exposed to PSS or sham-PSS. Continuous telemetric monitoring (24h/day sampling) was performed over the course of 7days. The electrocardiographic recordings were analyzed using the time- and frequency-domain indexes of heart rate variability (HRV). The behavioral response patterns were assessed using the elevated plus maze and acoustic startle response paradigms for the retrospective classification of individuals according to the PTSD-related cut-off behavioral criteria. During resting conditions, the male rats had significantly higher heart rates (HR) and lower HRV parameters than the female rats during both the active and inactive phases of the daily cycle. Immediately after PSS exposure, both the female and male rats demonstrated a robust increase in HR and a marked drop in HRV parameters, with a shift of sympathovagal balance towards sympathetic predominance. In both sexes, autonomic system habituation and recovery were selectively inhibited in the rats whose behavior was extremely disrupted after exposure to PSS. However, in the female rats, exposure to the PSS produced fewer EBR rats, with a more rapid recovery curve than that of the male rats. PSS did not induce changes to the circadian rhythm of the LMA. According to our results, PTSD can be conceptualized as a disorder that is related to failure-of-recovery mechanisms that impede the restitution of physiological homeostasis

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

    Science.gov (United States)

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

    2015-07-01

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

  13. Fatal cardiac arrhythmia after repeated exposure to 1,1-difluoroethane (DFE).

    Science.gov (United States)

    Avella, Joseph; Wilson, James C; Lehrer, Michael

    2006-03-01

    A 42-year-old man was found dead after repeated exposure to 1,1-difluoroethane (DFE, Freon 152a), a propellant found in CRC Duster, a product intended for the removal of dust and lint. Toxicologic analysis detected DFE in femoral blood 136.3 mg/L, brain 117.5 mg/kg, liver 87.6 mg/kg, lung 60.3 mg/kg, adipose 235.7 mg/kg, and vitreous fluid 25.1 mg/L. The cause of death was determined to be a fatal cardiac arrhythmia due to intoxication with 1,1-difluoroethane. After comparison to previously published cases involving DFE, we suggest that analysis of adipose tissue for DFE and similar compounds, along with blood and other tissues, may be useful in distinguishing between acute versus chronic exposure. Adipose may also be a valuable alternate specimen for detection in cases where loss or elimination from blood is likely to have occurred.

  14. Cardiac development in zebrafish and human embryonic stem cells is inhibited by exposure to tobacco cigarettes and e-cigarettes.

    Directory of Open Access Journals (Sweden)

    Nathan J Palpant

    Full Text Available Maternal smoking is a risk factor for low birth weight and other adverse developmental outcomes.We sought to determine the impact of standard tobacco cigarettes and e-cigarettes on heart development in vitro and in vivo.Zebrafish (Danio rerio were used to assess developmental effects in vivo and cardiac differentiation of human embryonic stem cells (hESCs was used as a model for in vitro cardiac development.In zebrafish, exposure to both types of cigarettes results in broad, dose-dependent developmental defects coupled with severe heart malformation, pericardial edema and reduced heart function. Tobacco cigarettes are more toxic than e-cigarettes at comparable nicotine concentrations. During cardiac differentiation of hESCs, tobacco smoke exposure results in a delayed transition through mesoderm. Both types of cigarettes decrease expression of cardiac transcription factors in cardiac progenitor cells, suggesting a persistent delay in differentiation. In definitive human cardiomyocytes, both e-cigarette- and tobacco cigarette-treated samples showed reduced expression of sarcomeric genes such as MLC2v and MYL6. Furthermore, tobacco cigarette-treated samples had delayed onset of beating and showed low levels and aberrant localization of N-cadherin, reduced myofilament content with significantly reduced sarcomere length, and increased expression of the immature cardiac marker smooth muscle alpha-actin.These data indicate a negative effect of both tobacco cigarettes and e-cigarettes on heart development in vitro and in vivo. Tobacco cigarettes are more toxic than E-cigarettes and exhibit a broader spectrum of cardiac developmental defects.

  15. Methods of estimating population exposures from Plowshare applications

    Energy Technology Data Exchange (ETDEWEB)

    Kaye, S V; Rohwer, P S [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1969-07-01

    When estimating doses to populations it is necessary to divide the total population into groups that have parameters of similar type and magnitude in order to identify critical population groups. Age groups constitute the most basic and generally useful way of dividing the total population for estimating dose. Models for estimating dose, particularly the internal dose from inhalation and ingestion of radioactivity, should be written as a function of age. The importance of considering age-dependency is emphasized by the fact that some of the internal dose parameters change by much as a factor of ten for some radionuclides when comparing a one year old with an adult. A computer code called INREM has been written which can consider all internal dose parameters as a function of age. The major imitation in using this computer code for all radionuclides is the paucity of age-dependent input data for many radionuclides. Tritium, iodine, cesium, and strontium have been studied in detail with INREM and the results and interpretations are discussed. Another code, EXREM, computes the external dose rates and cumulative doses from both beta particles and gamma photons from submersion in a radioactive cloud, submersion in contaminated water and exposure above a contaminated land surface. This code can consider up to 25 Plowshare detonations and a variety of combinations for calculating doses and dose rates in relation to a detonation schedule. The importance of using both INREM and EXREM to estimate the total dose to a population group is stressed. (author)

  16. Methods of estimating population exposures from Plowshare applications

    International Nuclear Information System (INIS)

    Kaye, S.V.; Rohwer, P.S.

    1969-01-01

    When estimating doses to populations it is necessary to divide the total population into groups that have parameters of similar type and magnitude in order to identify critical population groups. Age groups constitute the most basic and generally useful way of dividing the total population for estimating dose. Models for estimating dose, particularly the internal dose from inhalation and ingestion of radioactivity, should be written as a function of age. The importance of considering age-dependency is emphasized by the fact that some of the internal dose parameters change by much as a factor of ten for some radionuclides when comparing a one year old with an adult. A computer code called INREM has been written which can consider all internal dose parameters as a function of age. The major imitation in using this computer code for all radionuclides is the paucity of age-dependent input data for many radionuclides. Tritium, iodine, cesium, and strontium have been studied in detail with INREM and the results and interpretations are discussed. Another code, EXREM, computes the external dose rates and cumulative doses from both beta particles and gamma photons from submersion in a radioactive cloud, submersion in contaminated water and exposure above a contaminated land surface. This code can consider up to 25 Plowshare detonations and a variety of combinations for calculating doses and dose rates in relation to a detonation schedule. The importance of using both INREM and EXREM to estimate the total dose to a population group is stressed. (author)

  17. Estimation of exposure to furan in the Spanish population.

    Science.gov (United States)

    Mesías, Marta; Guerra-Hernández, Eduardo; García-Villanova, Belén

    2012-02-01

    The presence of furan in foods has received recent attention because of its association with harmful effects to human health. This compound, which is originated as a consequence of thermal treatment, is mainly found in canned, jarred, toasted and fried foods. The aim of this study was to estimate the exposure to furan in the Spanish population and to study the evolution of furan content in the main categories of foods in recent years, taking into account changes in dietary patterns. With respect to exposure to furan in the Spanish population from 2001 to 2009, no large differences were found. The maximum furan exposure recorded in this study (1.95 μg/kg bw/day) is lower than the 'no observable adverse effect level' of 0.08 mg/kg bw/day determined in the studies of experimental animals, and is close to the reported acceptable daily intake of 2 μg/kg bw/day.

  18. Estimation of internal exposure with use of urinalysis

    International Nuclear Information System (INIS)

    Nakagawa, Naoko; Kimura, Kayano

    2013-01-01

    Easily explained is a simple method to estimate the internal exposure to radio-cesium using the result of urinalysis. Urinary Cs (Cs-134, -137) concentration can be conveniently measured with Ge-detector of which sensitivity is as high as to detect even <1 Bq/L. At the steady state in the body, the ingested Cs amount is equivalent to the excreted amount; daily ingested Cs = daily excreted Cs (Bq/day): and 80% of body Cs is known to be excreted in urine; daily ingested Cs = daily urinary Cs/0.8= U x X/0.8 where U is daily urine volume (L) and X is Cs concentration (Bq/L) in the daily urine measurable with the detector. Thus the yearly internal exposure dose can be estimated by calculation using the body Cs (Bq/day) and the effective dose coefficient A (Sv/Bq) defined by ICRP (Pub. 72, 1998); A x U x X/0.8 x 365/1000 (mSv), where actually, the dose is committed effective dose for oral ingestion. A is dependent on the age. Alternatively, the level of body Cs at the equilibrium (Bq/kg, body weight M kg) can be estimated by B x U x X/0.8/M, where B, variable with age, is a dynamic parameter determined with half-lives and pharmacokinetic model of Cs (ICRP Pub. 56, 1990 and Pub. 67, 1992). Actually, the Cs urinalysis of 132 children was conducted in Iwate Prefecture in Dec. 2011-Mar. 2012. Their daily urinary Cs excretion was found to be in the range of not-detected (13 cases), <1 (20), <2 (48), <3 (33), <4 (15), to <5 (3) Bq/day; and when the not-detected 13 cases above were excluded below, daily Cs ingestion was from <1.25 to <6.25 Bq/day; internal exposure from <5.5 to <28 mc-Sv; body Cs level from <1.9 to <9.5 Bq/kg; and body Cs from <66 to <330 Bq. These were enough below the limit 1 mSv or 20 Bq/kg defined as a safety standard limit. Systematic survey of the internal exposure done in Fukushima Prefecture was that with the whole body counter, less sensitive than urinalysis (e.g., not detected at 7 Bq/kg). The advantage of the urinalysis is that anyone can easily

  19. Estimating the temporal distribution of exposure-related cancers

    International Nuclear Information System (INIS)

    Carter, R.L.; Sposto, R.; Preston, D.L.

    1993-09-01

    The temporal distribution of exposure-related cancers is relevant to the study of carcinogenic mechanisms. Statistical methods for extracting pertinent information from time-to-tumor data, however, are not well developed. Separation of incidence from 'latency' and the contamination of background cases are two problems. In this paper, we present methods for estimating both the conditional distribution given exposure-related cancers observed during the study period and the unconditional distribution. The methods adjust for confounding influences of background cases and the relationship between time to tumor and incidence. Two alternative methods are proposed. The first is based on a structured, theoretically derived model and produces direct inferences concerning the distribution of interest but often requires more-specialized software. The second relies on conventional modeling of incidence and is implemented through readily available, easily used computer software. Inferences concerning the effects of radiation dose and other covariates, however, are not always obtainable directly. We present three examples to illustrate the use of these two methods and suggest criteria for choosing between them. The first approach was used, with a log-logistic specification of the distribution of interest, to analyze times to bone sarcoma among a group of German patients injected with 224 Ra. Similarly, a log-logistic specification was used in the analysis of time to chronic myelogenous leukemias among male atomic-bomb survivors. We used the alternative approach, involving conventional modeling, to estimate the conditional distribution of exposure-related acute myelogenous leukemias among male atomic-bomb survivors, given occurrence between 1 October 1950 and 31 December 1985. All analyses were performed using Poisson regression methods for analyzing grouped survival data. (J.P.N.)

  20. Estimating core temperature in infants and children after cardiac surgery: a comparison of six methods.

    Science.gov (United States)

    Maxton, Fiona J C; Justin, Linda; Gillies, Donna

    2004-01-01

    Monitoring temperature in critically ill children is an important component of care, yet the accuracy of methods is often questioned. Temperature measured in the pulmonary artery is considered the 'gold standard', but this route is unsuitable for the majority of patients. An accurate, reliable and less invasive method is, however, yet to be established in paediatric intensive care work. To determine which site most closely reflects core temperature in babies and children following cardiac surgery, by comparing pulmonary artery temperature to the temperature measured at rectal, bladder, nasopharyngeal, axillary and tympanic sites. A convenience sample of 19 postoperative cardiac patients was studied. Temperature was recorded as a continuous measurement from pulmonary artery, rectal, nasopharyngeal and bladder sites. Axillary and tympanic temperatures were recorded at 30 minute intervals for 6 1/2 hours postoperatively. The small sample size of 19 infants and children limits the generalizability of the study. Repeated measures analysis of variance demonstrated no significant difference between pulmonary artery and bladder temperatures, and pulmonary artery and nasopharyngeal temperatures. Intraclass correlation showed that agreement was greatest between pulmonary artery temperature and temperature measured by bladder catheter. There was a significant difference between pulmonary artery temperature and temperature measured at rectal, tympanic and pulmonary artery and axillary sites. Repeated measures analysis showed a significant lag between pulmonary artery and rectal temperature of between 0 and 150 minutes after the 6-hour measurement period. In this study, bladder temperature was shown to be the best estimate of pulmonary artery temperature, closely followed by the temperature measured by nasopharyngeal probe. The results support the use of bladder or nasopharyngeal catheters to monitor temperature in critically ill children after cardiac surgery.

  1. Differential pulmonary and cardiac effects of pulmonary exposure to a panel of particulate matter-associated metals

    International Nuclear Information System (INIS)

    Wallenborn, J. Grace; Schladweiler, Mette J.; Richards, Judy H.; Kodavanti, Urmila P.

    2009-01-01

    Biological mechanisms underlying the association between particulate matter (PM) exposure and increased cardiovascular health effects are under investigation. Water-soluble metals reaching systemic circulation following pulmonary exposure are likely exerting a direct effect. However, it is unclear whether specific PM-associated metals may be driving this. We hypothesized that exposure to equimolar amounts of five individual PM-associated metals would cause differential pulmonary and cardiac effects. We exposed male WKY rats (14 weeks old) via a single intratracheal instillation (IT) to saline or 1 μmol/kg body weight of zinc, nickel, vanadium, copper, or iron in sulfate form. Responses were analyzed 4, 24, 48, or 96 h after exposure. Pulmonary effects were assessed by bronchoalveolar lavage fluid levels of total cells, macrophages, neutrophils, protein, albumin, and activities of lactate dehydrogenase, γ-glutamyl transferase, and n-acetyl glucosaminidase. Copper induced earlier pulmonary injury/inflammation, while zinc and nickel produced later effects. Vanadium or iron exposure induced minimal pulmonary injury/inflammation. Zinc, nickel, or copper increased serum cholesterol, red blood cells, and white blood cells at different time points. IT of nickel and copper increased expression of metallothionein-1 (MT-1) in the lung. Zinc, nickel, vanadium, and iron increased hepatic MT-1 expression. No significant changes in zinc transporter-1 (ZnT-1) expression were noted in the lung or liver; however, zinc increased cardiac ZnT-1 at 24 h, indicating a possible zinc-specific cardiac effect. Nickel exposure induced an increase in cardiac ferritin 96 h after IT. This data set demonstrating metal-specific cardiotoxicity is important in linking metal-enriched anthropogenic PM sources with adverse health effects.

  2. A survey of the radiation exposures received by the staff at two cardiac catheterization laboratories

    Energy Technology Data Exchange (ETDEWEB)

    McParland, B J [Cancer Control Agency of British Columbia, Victoria Cancer Clinic (Canada); Nosil, J; Burry, B [Victoria General Hospital (Canada)

    1990-11-01

    A study was made of exposures received by cardiologists and nurses working in two catheterization laboratories (Royal Jubilee Hospital, Victoria B.C. and the Victoria General Hospital), at various anatomical locations. One lab. performed primarily diagnostic procedures, the other international procedures. Results were used to assess the efficacy of personal shielding and to identify procedures followed by staff which elevated exposures. Data were also used to calculate estimates of upper limits of annual effective whole-body dose equivalent, H{sub E}, ranging from 13-19 mSv/yr for staff at both labs. Although these values are lower than the maximum of 50 mSv/yr, they are still significant and procedural modifications were made. Only nurses' eyes were estimated to receive annual dose equivalents approaching maximum and nurses now wear eye protection. (author).

  3. Cardiac-Specific Conversion Factors to Estimate Radiation Effective Dose From Dose-Length Product in Computed Tomography.

    Science.gov (United States)

    Trattner, Sigal; Halliburton, Sandra; Thompson, Carla M; Xu, Yanping; Chelliah, Anjali; Jambawalikar, Sachin R; Peng, Boyu; Peters, M Robert; Jacobs, Jill E; Ghesani, Munir; Jang, James J; Al-Khalidi, Hussein; Einstein, Andrew J

    2018-01-01

    This study sought to determine updated conversion factors (k-factors) that would enable accurate estimation of radiation effective dose (ED) for coronary computed tomography angiography (CTA) and calcium scoring performed on 12 contemporary scanner models and current clinical cardiac protocols and to compare these methods to the standard chest k-factor of 0.014 mSv·mGy -1 cm -1 . Accurate estimation of ED from cardiac CT scans is essential to meaningfully compare the benefits and risks of different cardiac imaging strategies and optimize test and protocol selection. Presently, ED from cardiac CT is generally estimated by multiplying a scanner-reported parameter, the dose-length product, by a k-factor which was determined for noncardiac chest CT, using single-slice scanners and a superseded definition of ED. Metal-oxide-semiconductor field-effect transistor radiation detectors were positioned in organs of anthropomorphic phantoms, which were scanned using all cardiac protocols, 120 clinical protocols in total, on 12 CT scanners representing the spectrum of scanners from 5 manufacturers (GE, Hitachi, Philips, Siemens, Toshiba). Organ doses were determined for each protocol, and ED was calculated as defined in International Commission on Radiological Protection Publication 103. Effective doses and scanner-reported dose-length products were used to determine k-factors for each scanner model and protocol. k-Factors averaged 0.026 mSv·mGy -1 cm -1 (95% confidence interval: 0.0258 to 0.0266) and ranged between 0.020 and 0.035 mSv·mGy -1 cm -1 . The standard chest k-factor underestimates ED by an average of 46%, ranging from 30% to 60%, depending on scanner, mode, and tube potential. Factors were higher for prospective axial versus retrospective helical scan modes, calcium scoring versus coronary CTA, and higher (100 to 120 kV) versus lower (80 kV) tube potential and varied among scanner models (range of average k-factors: 0.0229 to 0.0277 mSv·mGy -1 cm -1 ). Cardiac k

  4. Gestational exposure to diethylstilbestrol alters cardiac structure/function, protein expression and DNA methylation in adult male mice progeny

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Rami, E-mail: rami.haddad@mail.mcgill.ca [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada); Division of Experimental Medicine, Department of Medicine, McGill University, 850 Sherbrooke Street, Montréal, Québec, Canada H3A 1A2 (Canada); Kasneci, Amanda, E-mail: amanda.kasneci@mail.mcgill.ca [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada); Mepham, Kathryn, E-mail: katherine.mepham@mail.mcgill.ca [Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada); Division of Experimental Medicine, Department of Medicine, McGill University, 850 Sherbrooke Street, Montréal, Québec, Canada H3A 1A2 (Canada); Sebag, Igal A., E-mail: igal.sebag@mcgill.ca [Division of Cardiology, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec, Canada H3T 1E2 (Canada); and others

    2013-01-01

    Pregnant women, and thus their fetuses, are exposed to many endocrine disruptor compounds (EDCs). Fetal cardiomyocytes express sex hormone receptors making them potentially susceptible to re-programming by estrogenizing EDCs. Diethylstilbestrol (DES) is a proto-typical, non-steroidal estrogen. We hypothesized that changes in adult cardiac structure/function after gestational exposure to the test compound DES would be a proof in principle for the possibility of estrogenizing environmental EDCs to also alter the fetal heart. Vehicle (peanut oil) or DES (0.1, 1.0 and 10.0 μg/kg/da.) was orally delivered to pregnant C57bl/6n dams on gestation days 11.5–14.5. At 3 months, male progeny were left sedentary or were swim trained for 4 weeks. Echocardiography of isoflurane anesthetized mice revealed similar cardiac structure/function in all sedentary mice, but evidence of systolic dysfunction and increased diastolic relaxation after swim training at higher DES doses. The calcium homeostasis proteins, SERCA2a, phospholamban, phospho-serine 16 phospholamban and calsequestrin 2, are important for cardiac contraction and relaxation. Immunoblot analyses of ventricle homogenates showed increased expression of SERCA2a and calsequestrin 2 in DES mice and greater molecular remodeling of these proteins and phospho-serine 16 phospholamban in swim trained DES mice. DES increased cardiac DNA methyltransferase 3a expression and DNA methylation in the CpG island within the calsequestrin 2 promoter in heart. Thus, gestational DES epigenetically altered ventricular DNA, altered cardiac function and expression, and reduced the ability of adult progeny to cardiac remodel when physically challenged. We conclude that gestational exposure to estrogenizing EDCs may impact cardiac structure/function in adult males. -- Highlights: ► Gestational DES changes cardiac SERCA2a and CASQ2 expression. ► Echocardiography identified systolic dysfunction and increased diastolic relaxation. ► DES

  5. Pilot Study: Estimation of Stroke Volume and Cardiac Output from Pulse Wave Velocity.

    Directory of Open Access Journals (Sweden)

    Yurie Obata

    Full Text Available Transesophageal echocardiography (TEE is increasingly replacing thermodilution pulmonary artery catheters to assess hemodynamics in patients at high risk for cardiovascular morbidity. However, one of the drawbacks of TEE compared to pulmonary artery catheters is the inability to measure real time stroke volume (SV and cardiac output (CO continuously. The aim of the present proof of concept study was to validate a novel method of SV estimation, based on pulse wave velocity (PWV in patients undergoing cardiac surgery.This is a retrospective observational study. We measured pulse transit time by superimposing the radial arterial waveform onto the continuous wave Doppler waveform of the left ventricular outflow tract, and calculated SV (SVPWV using the transformed Bramwell-Hill equation. The SV measured by TEE (SVTEE was used as a reference.A total of 190 paired SV were measured from 28 patients. A strong correlation was observed between SVPWV and SVTEE with the coefficient of determination (R2 of 0.71. A mean difference between the two (bias was 3.70 ml with the limits of agreement ranging from -20.33 to 27.73 ml and a percentage error of 27.4% based on a Bland-Altman analysis. The concordance rate of two methods was 85.0% based on a four-quadrant plot. The angular concordance rate was 85.9% with radial limits of agreement (the radial sector that contained 95% of the data points of ± 41.5 degrees based on a polar plot.PWV based SV estimation yields reasonable agreement with SV measured by TEE. Further studies are required to assess its utility in different clinical situations.

  6. Is exposure to ionising radiation associated with childhood cardiac arrhythmia in the Russian territories contaminated by the Chernobyl fallout? A cross-sectional population-based study.

    Science.gov (United States)

    Jourdain, Jean-Rene; Landon, Geraldine; Clero, Enora; Doroshchenko, Vladimir; Silenok, Aleksandr; Kurnosova, Irina; Butsenin, Andrei; Denjoy, Isabelle; Franck, Didier; Heuze, Jean-Pierre; Gourmelon, Patrick

    2018-03-25

    To investigate childhood cardiac arrhythmia and chronic exposure to caesium-137 ( 137 Cs) resulting from the Chernobyl accident. Prospective cross-sectional study using exposed/unexposed design conducted in the Bryansk region from May 2009 to May 2013 on children selected on the basis of 137 Cs soil deposition: control territories ([ 137 Cs]555 kBq per square metre, where children were considered as exposed). Russian territories affected by the Chernobyl fallout (Bryansk region). This cross-sectional study included 18 152 children aged 2-18 years and living in the Bryansk region (Russia). All children received three medical examinations (ECG, echocardiography and 137 Cs whole-body activity measurement) and some of them were given with a 24-hour Holter monitoring and blood tests. Cardiac arrhythmia was diagnosed in 1172 children living in contaminated territories and 1354 children living in control territories. The crude prevalence estimated to 13.3% in contaminated territories was significantly lower than in control territories with 15.2% over the period 2009-2013 (PChernobyl fallout. The suspected increase of cardiac arrhythmia in children exposed to Chernobyl fallout is not confirmed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  7. Emerging Tools to Estimate and to Predict Exposures to ...

    Science.gov (United States)

    The timely assessment of the human and ecological risk posed by thousands of existing and emerging commercial chemicals is a critical challenge facing EPA in its mission to protect public health and the environment The US EPA has been conducting research to enhance methods used to estimate and forecast exposures for tens of thousands of chemicals. This research is aimed at both assessing risks and supporting life cycle analysis, by developing new models and tools for high throughput exposure screening and prioritization, as well as databases that support these and other tools, especially regarding consumer products. The models and data address usage, and take advantage of quantitative structural activity relationships (QSARs) for both inherent chemical properties and function (why the chemical is a product ingredient). To make them more useful and widely available, the new tools, data and models are designed to be: • Flexible • Intraoperative • Modular (useful to more than one, stand-alone application) • Open (publicly available software) Presented at the Society for Risk Analysis Forum: Risk Governance for Key Enabling Technologies, Venice, Italy, March 1-3, 2017

  8. Association of HeartMate II left ventricular assist device flow estimate with thermodilution cardiac output.

    Science.gov (United States)

    Hasin, Tal; Huebner, Marianne; Li, Zhuo; Brown, Daniel; Stulak, John M; Boilson, Barry A; Joyce, Lyle; Pereira, Naveen L; Kushwaha, Sudhir S; Park, Soon J

    2014-01-01

    Cardiac output (CO) assessment is important in treating patients with heart failure. Durable left ventricular assist devices (LVADs) provide essentially all CO. In currently used LVADs, estimated device flow is generated by a computerized algorithm. However, LVAD flow estimate may be inaccurate in tracking true CO. We correlated LVAD (HeartMate II) flow with thermodilution CO during postoperative care (day 2-10 after implant) in 81 patients (5,616 paired measurements). Left ventricular assist device flow and CO correlated with a low correlation coefficient (r = 0.42). Left ventricular assist device readings were lower than CO measurements by approximately 0.36 L/min, trending for larger difference with higher values. Left ventricular assist device flow measurements showed less temporal variability compared with CO. Grouping for simultaneous measured blood pressure (BP device flow generally trends with measured CO, but large variability exists, hence flow measures should not be assumed to equal with CO. Clinicians should take into account variables such as high CO, BP, and opening of the aortic valve when interpreting LVAD flow readout. Direct flow sensors incorporated in the LVAD system may allow for better estimation.

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

    Science.gov (United States)

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

    2016-02-01

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

  10. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Geisel, Dominik; Zimmermann, Elke; Rief, Matthias; Greupner, Johannes; Hamm, Bernd [Charite Medical School, Department of Radiology, Berlin (Germany); Laule, Michael; Knebel, Fabian [Charite Medical School, Department of Cardiology, Berlin (Germany); Dewey, Marc [Charite Medical School, Department of Radiology, Berlin (Germany); Charite, Institut fuer Radiologie, Berlin (Germany)

    2012-08-15

    To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. On average there were 0.12 {+-} 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 {+-} 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. (orig.)

  11. Radiation exposure of pediatric patients and physicians during cardiac catheterization and balloon pulmonary valvuloplasty.

    Science.gov (United States)

    Wu, J R; Huang, T Y; Wu, D K; Hsu, P C; Weng, P S

    1991-07-15

    Thermoluminescent dosimeters were applied to various areas of 61 pediatric patients and physicians to measure radiation doses during routine cardiac catheterization and during 4 cases of balloon pulmonary valvuloplasty. Radiation doses were measured during chest roentgenography, fluoroscopy and cineangiography. Average skin dose to the chest was 121 microGy during chest x-ray, 5,182 microGy during catheterization and 641 mGy during valvuloplasty. For the eyes, thyroid and gonads of the patients, the exposure during routine catheterization was equal to 0.4, 6 and 0.2 chest x-rays, respectively. Radiation dose of the operator was 3 microGy for the eyes and 6 miCroGy in the thyroid. About 56% of the operator's dose could be reduced by thyroid shields, and 80% by lead aprons. The assistant received only 1 microGy outside the thyroid shield. Therefore, we have concluded that the patients' dose during routine catheterization is largely based on our experimental results, but the dose is acceptable based on the risk factor analysis. The skin dose to the right lateral chest of the patient during valvuloplasty is extremely high, perhaps as high as the equivalent of 1,000 chest x-rays. Besides the clinical benefits of valvuloplasty, the long-term radiation-related hazards to the patient should be carefully monitored.

  12. Radiation exposure of pediatric patients and physicians during cardiac catheterization and balloon pulmonary valvuloplasty

    International Nuclear Information System (INIS)

    Wu, J.R.; Huang, T.Y.; Wu, D.K.; Hsu, P.C.; Weng, P.S.

    1991-01-01

    Thermoluminescent dosimeters were applied to various areas of 61 pediatric patients and physicians to measure radiation doses during routine cardiac catheterization and during 4 cases of balloon pulmonary valvuloplasty. Radiation doses were measured during chest roentgenography, fluoroscopy and cineangiography. Average skin dose to the chest was 121 microGy during chest x-ray, 5,182 microGy during catheterization and 641 mGy during valvuloplasty. For the eyes, thyroid and gonads of the patients, the exposure during routine catheterization was equal to 0.4, 6 and 0.2 chest x-rays, respectively. Radiation dose of the operator was 3 microGy for the eyes and 6 miCroGy in the thyroid. About 56% of the operator's dose could be reduced by thyroid shields, and 80% by lead aprons. The assistant received only 1 microGy outside the thyroid shield. Therefore, the authors have concluded that the patients dose during routine catheterization is largely based on our experimental results, but the dose is acceptable based on the risk factor analysis. The skin dose to the right lateral chest of the patient during valvuloplasty is extremely high, perhaps as high as the equivalent of 1,000 chest x-rays. Besides the clinical benefits of valvuloplasty, the long-term radiation-related hazards to the patient should be carefully monitored

  13. Estimation of radiation dose and risk to children undergoing cardiac catheterization for the treatment of a congenital heart disease using Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Yakoumakis, Emmanuel; Kostopoulou, Helen; Dimitriadis, Anastastios; Georgiou, Evaggelos [University of Athens, Medical Physics Department, Medical School, Athens (Greece); Makri, Triantafilia [' Agia Sofia' Hospital, Medical Physics Unit, Athens (Greece); Tsalafoutas, Ioannis [Anticancer-Oncology Hospital of Athens ' Agios Savvas' , Medical Physics Department, Athens (Greece)

    2013-03-15

    Children diagnosed with congenital heart disease often undergo cardiac catheterization for their treatment, which involves the use of ionizing radiation and therefore a risk of radiation-induced cancer. The purpose of this study was to calculate the effective and equivalent organ doses (H{sub T}) in those children and estimate the risk of exposure-induced death. Fifty-three children were divided into three groups: atrial septal defect (ASD), ventricular septal defect (VSD) and patent ductus arteriosus (PDA). In all procedures, the exposure conditions and the dose-area product meters readings were recorded for each individual acquisition. Monte Carlo simulations were run using the PCXMC 2.0 code and mathematical phantoms simulating a child's anatomy. The H{sub T} values to all irradiated organs and the resulting E and risk of exposure-induced death values were calculated. The average dose-area product values were, respectively, 40 {+-} 12 Gy.cm{sup 2} for the ASD, 17.5 {+-} 0.7 Gy.cm{sup 2} for the VSD and 9.5 {+-} 1 Gy.cm{sup 2} for the PDA group. The average E values were 40 {+-} 12, 22 {+-} 2.5 and 17 {+-} 3.6 mSv for ASD, VSD and PDA groups, respectively. The respective estimated risk of exposure-induced death values per procedure were 0.109, 0.106 and 0.067%. Cardiac catheterizations in children involve a considerable risk for radiation-induced cancer that has to be further reduced. (orig.)

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  15. Lesion size estimator of cardiac radiofrequency ablation at different common locations with different tip temperatures.

    Science.gov (United States)

    Lai, Yu-Chi; Choy, Young Bin; Haemmerich, Dieter; Vorperian, Vicken R; Webster, John G

    2004-10-01

    Finite element method (FEM) analysis has become a common method to analyze the lesion formation during temperature-controlled radiofrequency (RF) cardiac ablation. We present a process of FEM modeling a system including blood, myocardium, and an ablation catheter with a thermistor embedded at the tip. The simulation used a simple proportional-integral (PI) controller to control the entire process operated in temperature-controlled mode. Several factors affect the lesion size such as target temperature, blood flow rate, and application time. We simulated the time response of RF ablation at different locations by using different target temperatures. The applied sites were divided into two groups each with a different convective heat transfer coefficient. The first group was high-flow such as the atrioventricular (AV) node and the atrial aspect of the AV annulus, and the other was low-flow such as beneath the valve or inside the coronary sinus. Results showed the change of lesion depth and lesion width with time, under different conditions. We collected data for all conditions and used it to create a database. We implemented a user-interface, the lesion size estimator, where the user enters set temperature and location. Based on the database, the software estimated lesion dimensions during different applied durations. This software could be used as a first-step predictor to help the electrophysiologist choose treatment parameters.

  16. Investigation of occupational radiation exposure during interventional cardiac catheterizations performed via radial artery

    International Nuclear Information System (INIS)

    Goni, H.; Papadopoulou, D.; Yakoumakis, Em; Stratigis, N.; Benos, J.; Siriopoulou, V.; Makri, Tr; Georgiou, Ev

    2005-01-01

    The purpose of this study was to determine the thyroid, sternum and hand radiation doses of radiologists who perform angiographies and angio-plasties via the radial artery. Staff radiation dose was estimated for 21 cardiac interventional catheterizations. Thermoluminescence dosemeters (TLDs) were used to determine radiation dose for each procedure at the right and left wrist, at the sternum and the thyroid. A dose area product (DAP) meter was also attached to give a direct value in Gy cm 2 for each procedure. Staff radiation doses varied between 34 and 235 μGy per procedure at the left wrist, 28 and 172 μGy at the right wrist, 16 and 106 μGy at the level of the thyroid and 16 and 154 μGy at the level of the sternum. The DAP values varied between 25 and 167 Gy cm 2 . Radiation doses in this study are comparable to those reported in previous studies. Moreover, good correlation was found between the DAP values and the occupational dose measured with TLDs. (authors)

  17. 1. Dose reduction of occupational exposure in cardiac catheterization and angiography

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Yoshimi [Kyushu Kosei Nenkin Hospital, Kitakyushu, Fukuoka (Japan); Matsumoto, Kunihiro; Fujihashi, Hiroshi; Umeda, Kazuhiro

    2000-08-01

    Occupational exposure to scattered radiation and protective equipment was assessed in 4 medical institutions in Kyushu, Japan. The areas where scattered radiation occurred, the scattered radiation dose in the operator's position, fluoroscopy time, the number of cinematography sessions, and annual number of patients were assessed, and the annual scattered radiation dose to the operator was estimated. Approximately 90% of scattered radiation was generated by the subject and the collimator. Measurement of scattered radiation during coronary arteriography yielded a dose of 255-1200 [{mu}Sv/hr.] during fluoroscopy and 3.8-26.7 [{mu}Sv/10 sec.] during radiography. The duration of fluoroscopy for ablation was much longer than during general examinations and PTCA, suggesting a possible contribution to occupational exposure. The data for the past 5 years show no marked change in total number of catheterizations, but the number of ablations has rapidly increased. Ablation requires specific skills, and thus it is frequently performed by only a few staff members, resulting in exposure being concentrated in a few specific persons. The estimated doses of scattered radiation to the eyes and thyroid gland, which are assumed to be the most highly exposed sites, were 116.2 [mSv/year] during fluoroscopy and 8.9 [mSv/year] during radiography, for a total of 125.1 [mSv/year]. This dose is very close to the maximum occupational exposure dose recommended by International Commission on Radiological Protection (ICRP), i.e., 150 [mSv/year]. A protective device that does not impose a burden on the operator or limit the functions of x-ray units was installed on top of the examining table as a measure to reduce the occupational dose. In an experiment using this device the scattered radiation dose during inguinal puncture decreased from 0.8 [mSv/hr.] to 0.02 [mSv/hr.], and the shielding rate was 2.5%. The dose was reduced 97.5%. The authors conclude that radiological personnel must make

  18. Comparison of modeled estimates of inhalation exposure to aerosols during use of consumer spray products.

    Science.gov (United States)

    Park, Jihoon; Yoon, Chungsik; Lee, Kiyoung

    2018-05-30

    In the field of exposure science, various exposure assessment models have been developed to complement experimental measurements; however, few studies have been published on their validity. This study compares the estimated inhaled aerosol doses of several inhalation exposure models to experimental measurements of aerosols released from consumer spray products, and then compares deposited doses within different parts of the human respiratory tract according to deposition models. Exposure models, including the European Center for Ecotoxicology of Chemicals Targeted Risk Assessment (ECETOC TRA), the Consumer Exposure Model (CEM), SprayExpo, ConsExpo Web and ConsExpo Nano, were used to estimate the inhaled dose under various exposure scenarios, and modeled and experimental estimates were compared. The deposited dose in different respiratory regions was estimated using the International Commission on Radiological Protection model and multiple-path particle dosimetry models under the assumption of polydispersed particles. The modeled estimates of the inhaled doses were accurate in the short term, i.e., within 10 min of the initial spraying, with a differences from experimental estimates ranging from 0 to 73% among the models. However, the estimates for long-term exposure, i.e., exposure times of several hours, deviated significantly from the experimental estimates in the absence of ventilation. The differences between the experimental and modeled estimates of particle number and surface area were constant over time under ventilated conditions. ConsExpo Nano, as a nano-scale model, showed stable estimates of short-term exposure, with a difference from the experimental estimates of less than 60% for all metrics. The deposited particle estimates were similar among the deposition models, particularly in the nanoparticle range for the head airway and alveolar regions. In conclusion, the results showed that the inhalation exposure models tested in this study are suitable

  19. Deinhibition of cardiac Na/sup +/-K/sup +/-ATPase after exposure to exogenous phospholipase A/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Colvin, R.A.

    1987-01-01

    After 2 h of exogenous phospholipase A/sub 2/ (PLA/sub 2/) exposure, membrane phospholipid decreased from 3.22 +/- 0.31 to 1.06 +/- 0.13 ..mu..mol/mg (33% of control). All classes of phospholipid, except sphingomyelin, were hydrolyzed, whereas total cholesterol content was unaffected. Increases in nonesterified fatty acids (NEFA) were reflected primarily in oleic (18:1), linoleic (18:2), and arachidonic (20:4). Na/sup +/-K/sup +/-adenosinetriphosphatase (ATPase) activity was inhibited to 29% of control by 2 h of PLA/sub 2/ treatment, and this inhibition was reversed (albeit, not completely after 5 min of PLA/sub 2/ treatment) by removal of the hydrolysis products with 0.1% bovine serum albumin (BSA). In contrast, the apparent binding capacity for (/sup 3/H)ouabain was not affected by PLA/sub 2/ treatment. Unmasking of latent (/sup 3/H)ouabain binding by alamethicin was utilized to estimate changes in the proportion of sealed vesicles present before and after PLA/sub 2/ treatment. PLA/sub 2/ treatment resulted in a time-dependent loss of sealed vesicles that paralleled the time course of phospholipid hydrolysis and was not reversed by washing with BSA. These studies demonstrate that cardiac Na/sup +/-K/sup +/-ATPase activity is inhibited by accumulation of endogenously produced lysophospholipids and NEFA. In contrast, loss of vesicle integrity may result from both accumulation of endogenously produced hydrolysis products and membrane phospholipid depletion.

  20. Noise Exposure Estimates of Urban MP3 Player Users

    Science.gov (United States)

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

    2011-01-01

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

  1. Health impact assessment of air pollution using a dynamic exposure profile: Implications for exposure and health impact estimates

    International Nuclear Information System (INIS)

    Dhondt, Stijn; Beckx, Carolien; Degraeuwe, Bart; Lefebvre, Wouter; Kochan, Bruno; Bellemans, Tom; Int Panis, Luc; Macharis, Cathy; Putman, Koen

    2012-01-01

    In both ambient air pollution epidemiology and health impact assessment an accurate assessment of the population exposure is crucial. Although considerable advances have been made in assessing human exposure outdoors, the assessments often do not consider the impact of individual travel behavior on such exposures. Population-based exposures to NO 2 and O 3 using only home addresses were compared with models that integrate all time-activity patterns—including time in commute—for Flanders and Brussels. The exposure estimates were used to estimate the air pollution impact on years of life lost due to respiratory mortality. Health impact of NO 2 using an exposure that integrates time-activity information was on average 1.2% higher than when assuming that people are always at their home address. For ozone the overall estimated health impact was 0.8% lower. Local differences could be much larger, with estimates that differ up to 12% from the exposure using residential addresses only. Depending on age and gender, deviations from the population average were seen. Our results showed modest differences on a regional level. At the local level, however, time-activity patterns indicated larger differences in exposure and health impact estimates, mainly for people living in more rural areas. These results suggest that for local analyses the dynamic approach can contribute to an improved assessment of the health impact of various types of pollution and to the understanding of exposure differences between population groups. - Highlights: ► Exposure to ambient air pollution was assessed integrating population mobility. ► This dynamic exposure was integrated into a health impact assessment. ► Differences between the dynamic and residential exposure were quantified. ► Modest differences in health impact were found at a regional level. ► At municipal level larger differences were found, influenced by gender and age.

  2. Health impact assessment of air pollution using a dynamic exposure profile: Implications for exposure and health impact estimates

    Energy Technology Data Exchange (ETDEWEB)

    Dhondt, Stijn, E-mail: stijn.dhondt@vub.ac.be [Department of Medical Sociology and Health Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090, Brussels (Belgium); Beckx, Carolien, E-mail: Carolien.Beckx@vito.be [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Degraeuwe, Bart, E-mail: Bart.Degraeuwe@vito.be [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Lefebvre, Wouter, E-mail: Wouter.Lefebvre@vito.be [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Kochan, Bruno, E-mail: Bruno.Kochan@uhasselt.be [Transportation Research Institute, Hasselt University, Wetenschapspark 5 bus 6, 3590 Diepenbeek (Belgium); Bellemans, Tom, E-mail: Tom.Bellemans@uhasselt.be [Transportation Research Institute, Hasselt University, Wetenschapspark 5 bus 6, 3590 Diepenbeek (Belgium); Int Panis, Luc, E-mail: Luc.intpanis@vito.be [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Transportation Research Institute, Hasselt University, Wetenschapspark 5 bus 6, 3590 Diepenbeek (Belgium); Macharis, Cathy, E-mail: cjmachar@vub.ac.be [Department MOSI-Transport and Logistics, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels (Belgium); Putman, Koen, E-mail: kputman@vub.ac.be [Department of Medical Sociology and Health Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090, Brussels (Belgium); Interuniversity Centre for Health Economics Research (I-CHER), Vrije Universiteit Brussel, Brussels (Belgium)

    2012-09-15

    In both ambient air pollution epidemiology and health impact assessment an accurate assessment of the population exposure is crucial. Although considerable advances have been made in assessing human exposure outdoors, the assessments often do not consider the impact of individual travel behavior on such exposures. Population-based exposures to NO{sub 2} and O{sub 3} using only home addresses were compared with models that integrate all time-activity patterns-including time in commute-for Flanders and Brussels. The exposure estimates were used to estimate the air pollution impact on years of life lost due to respiratory mortality. Health impact of NO{sub 2} using an exposure that integrates time-activity information was on average 1.2% higher than when assuming that people are always at their home address. For ozone the overall estimated health impact was 0.8% lower. Local differences could be much larger, with estimates that differ up to 12% from the exposure using residential addresses only. Depending on age and gender, deviations from the population average were seen. Our results showed modest differences on a regional level. At the local level, however, time-activity patterns indicated larger differences in exposure and health impact estimates, mainly for people living in more rural areas. These results suggest that for local analyses the dynamic approach can contribute to an improved assessment of the health impact of various types of pollution and to the understanding of exposure differences between population groups. - Highlights: Black-Right-Pointing-Pointer Exposure to ambient air pollution was assessed integrating population mobility. Black-Right-Pointing-Pointer This dynamic exposure was integrated into a health impact assessment. Black-Right-Pointing-Pointer Differences between the dynamic and residential exposure were quantified. Black-Right-Pointing-Pointer Modest differences in health impact were found at a regional level. Black

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

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  4. Relation of whole blood carboxyhemoglobin concentration to ambient carbon monoxide exposure estimated using regression.

    Science.gov (United States)

    Rudra, Carole B; Williams, Michelle A; Sheppard, Lianne; Koenig, Jane Q; Schiff, Melissa A; Frederick, Ihunnaya O; Dills, Russell

    2010-04-15

    Exposure to carbon monoxide (CO) and other ambient air pollutants is associated with adverse pregnancy outcomes. While there are several methods of estimating CO exposure, few have been evaluated against exposure biomarkers. The authors examined the relation between estimated CO exposure and blood carboxyhemoglobin concentration in 708 pregnant western Washington State women (1996-2004). Carboxyhemoglobin was measured in whole blood drawn around 13 weeks' gestation. CO exposure during the month of blood draw was estimated using a regression model containing predictor terms for year, month, street and population densities, and distance to the nearest major road. Year and month were the strongest predictors. Carboxyhemoglobin level was correlated with estimated CO exposure (rho = 0.22, 95% confidence interval (CI): 0.15, 0.29). After adjustment for covariates, each 10% increase in estimated exposure was associated with a 1.12% increase in median carboxyhemoglobin level (95% CI: 0.54, 1.69). This association remained after exclusion of 286 women who reported smoking or being exposed to secondhand smoke (rho = 0.24). In this subgroup, the median carboxyhemoglobin concentration increased 1.29% (95% CI: 0.67, 1.91) for each 10% increase in CO exposure. Monthly estimated CO exposure was moderately correlated with an exposure biomarker. These results support the validity of this regression model for estimating ambient CO exposures in this population and geographic setting.

  5. Ultrasound estimation of volume of postoperative pleural effusion in cardiac surgery patients.

    Science.gov (United States)

    Usta, Engin; Mustafi, Migdat; Ziemer, Gerhard

    2010-02-01

    The aim of this study was to establish a practical simplified formula to facilitate the management of a frequently occurring postoperative complication, pleural effusion. Chest ultrasonography with better sensitivity and reliability in the diagnosis of pleural effusions than chest X-ray can be repeated serially at the bedside without any radiation risk. One hundred and fifty patients after cardiac surgery with basal pleural opacity on chest X-ray have been included in our prospective observational study during a two-year period. Effusion was confirmed on postoperative day (POD) 5.9+/-3.2 per chest ultrasound sonography. Inclusion criteria for subsequent thoracentesis based on clinical grounds alone and were not protocol-driven. Major inclusion criteria were: dyspnea and peripheral oxygen saturation (SpO(2)) levels or = 30 mm). One hundred and thirty-five patients (90%) were drained with a 14-G needle if according to the simplified formula: V (ml)=[16 x D (mm)] the volume of the pleural effusion was around 500 ml. The success rate of obtaining fluid was 100% without any complications. There is a high accuracy between the estimated and drained pleural effusion. Simple quantification of pleural effusion enables time and cost-effective decision-making for thoracentesis in postoperative patients.

  6. Cardiac parasympathetic outflow during dynamic exercise in humans estimated from power spectral analysis of P-P interval variability.

    Science.gov (United States)

    Takahashi, Makoto; Nakamoto, Tomoko; Matsukawa, Kanji; Ishii, Kei; Watanabe, Tae; Sekikawa, Kiyokazu; Hamada, Hironobu

    2016-03-01

    What is the central question of this study? Should we use the high-frequency (HF) component of P-P interval as an index of cardiac parasympathetic nerve activity during moderate exercise? What is the main finding and its importance? The HF component of P-P interval variability remained even at a heart rate of 120-140 beats min(-1) and was further reduced by atropine, indicating incomplete cardiac vagal withdrawal during moderate exercise. The HF component of R-R interval is invalid as an estimate of cardiac parasympathetic outflow during moderate exercise; instead, the HF component of P-P interval variability should be used. The high-frequency (HF) component of R-R interval variability has been widely used as an indirect estimate of cardiac parasympathetic (vagal) outflow to the sino-atrial node of the heart. However, we have recently found that the variability of the R-R interval becomes much smaller during dynamic exercise than that of the P-P interval above a heart rate (HR) of ∼100 beats min(-1). We hypothesized that cardiac parasympathetic outflow during dynamic exercise with a higher intensity may be better estimated using the HF component of P-P interval variability. To test this hypothesis, the HF components of both P-P and R-R interval variability were analysed using a Wavelet transform during dynamic exercise. Twelve subjects performed ergometer exercise to increase HR from the baseline of 69 ± 3 beats min(-1) to three different levels of 100, 120 and 140 beats min(-1). We also examined the effect of atropine sulfate on the HF components in eight of the 12 subjects during exercise at an HR of 140 beats min(-1) . The HF component of P-P interval variability was significantly greater than that of R-R interval variability during exercise, especially at the HRs of 120 and 140 beats min(-1). The HF component of P-P interval variability was more reduced by atropine than that of R-R interval variability. We conclude that cardiac parasympathetic outflow to the

  7. Estimated Aortic Stiffness is Independently Associated with Cardiac Baroreflex Sensitivity in Humans: Role of Aging and Habitual Endurance Exercise

    Science.gov (United States)

    Pierce, Gary L.; Harris, Stephen A.; Seals, Douglas R.; Casey, Darren P.; Barlow, Patrick B.; Stauss, Harald M.

    2016-01-01

    We hypothesized that differences in cardiac baroreflex sensitivity (BRS) would be independently associated with aortic stiffness and augmentation index (AI), clinical biomarkers of cardiovascular disease (CVD) risk, among young sedentary and middle-aged/older sedentary and endurance-trained adults. A total of 36 healthy middle-aged/older (age 55-76 years, n=22 sedentary; n=14 endurance-trained) and 5 young sedentary (age 18-31 years) adults were included in a cross-sectional study. A subset of the middle-aged/older sedentary adults (n=12) completed an 8-week aerobic exercise intervention. Invasive brachial artery blood pressure waveforms were used to compute spontaneous cardiac BRS (via sequence technique) and estimated aortic pulse wave velocity (PWV) and AI (AI, via brachial-aortic transfer function and wave separation analysis). In the cross-sectional study, cardiac BRS was 71% lower in older compared with young sedentary adults (Pendurance exercise (P=0.03). In a regression model that included age, sex, resting heart rate, mean arterial pressure (MAP), body mass index and maximal exercise oxygen uptake, estimated aortic PWV (β±SE = −5.76 ± 2.01, P=0.01) was the strongest predictor of BRS (Model R2=0.59, Pendurance exercise-related differences in cardiac BRS are independently associated with corresponding alterations in aortic PWV among healthy adults, consistent with a mechanistic link between variations in the sensitivity of the baroreflex and aortic stiffness with age and exercise. PMID:26911535

  8. Estimated aortic stiffness is independently associated with cardiac baroreflex sensitivity in humans: role of ageing and habitual endurance exercise.

    Science.gov (United States)

    Pierce, G L; Harris, S A; Seals, D R; Casey, D P; Barlow, P B; Stauss, H M

    2016-09-01

    We hypothesised that differences in cardiac baroreflex sensitivity (BRS) would be independently associated with aortic stiffness and augmentation index (AI), clinical biomarkers of cardiovascular disease risk, among young sedentary and middle-aged/older sedentary and endurance-trained adults. A total of 36 healthy middle-aged/older (age 55-76 years, n=22 sedentary and n=14 endurance-trained) and 5 young sedentary (age 18-31 years) adults were included in a cross-sectional study. A subset of the middle-aged/older sedentary adults (n=12) completed an 8-week-aerobic exercise intervention. Invasive brachial artery blood pressure waveforms were used to compute spontaneous cardiac BRS (via sequence technique), estimated aortic pulse wave velocity (PWV) and AI (AI, via brachial-aortic transfer function and wave separation analysis). In the cross-sectional study, cardiac BRS was 71% lower in older compared with young sedentary adults (Pendurance exercise (P=0.03). In a regression model that included age, sex, resting heart rate, mean arterial pressure (MAP), body mass index and maximal exercise oxygen uptake, estimated aortic PWV (β±s.e.=-5.76±2.01, P=0.01) was the strongest predictor of BRS (model R(2)=0.59, Pendurance-exercise-related differences in cardiac BRS are independently associated with corresponding alterations in aortic PWV among healthy adults, consistent with a mechanistic link between variations in the sensitivity of the baroreflex and aortic stiffness with age and exercise.

  9. Estimation of cardiac motion in cine-MRI sequences by correlation transform optical flow of monogenic features distance

    Science.gov (United States)

    Gao, Bin; Liu, Wanyu; Wang, Liang; Liu, Zhengjun; Croisille, Pierre; Delachartre, Philippe; Clarysse, Patrick

    2016-12-01

    Cine-MRI is widely used for the analysis of cardiac function in clinical routine, because of its high soft tissue contrast and relatively short acquisition time in comparison with other cardiac MRI techniques. The gray level distribution in cardiac cine-MRI is relatively homogenous within the myocardium, and can therefore make motion quantification difficult. To ensure that the motion estimation problem is well posed, more image features have to be considered. This work is inspired by a method previously developed for color image processing. The monogenic signal provides a framework to estimate the local phase, orientation, and amplitude, of an image, three features which locally characterize the 2D intensity profile. The independent monogenic features are combined into a 3D matrix for motion estimation. To improve motion estimation accuracy, we chose the zero-mean normalized cross-correlation as a matching measure, and implemented a bilateral filter for denoising and edge-preservation. The monogenic features distance is used in lieu of the color space distance in the bilateral filter. Results obtained from four realistic simulated sequences outperformed two other state of the art methods even in the presence of noise. The motion estimation errors (end point error) using our proposed method were reduced by about 20% in comparison with those obtained by the other tested methods. The new methodology was evaluated on four clinical sequences from patients presenting with cardiac motion dysfunctions and one healthy volunteer. The derived strain fields were analyzed favorably in their ability to identify myocardial regions with impaired motion.

  10. 75 FR 16120 - Notice of Issuance of Exposure Draft on Accrual Estimates for Grant Programs

    Science.gov (United States)

    2010-03-31

    ... FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Notice of Issuance of Exposure Draft on Accrual Estimates for Grant Programs AGENCY: Federal Accounting Standards Advisory Board. ACTION: Notice. Board... Accounting Technical Release entitled Accrual Estimates for Grant Programs. The proposed Technical Release...

  11. Noninvasive Ambient Pressure Estimation using Ultrasound Contrast Agents -- Invoking Subharmonics for Cardiac and Hepatic Applications

    Science.gov (United States)

    Dave, Jaydev K.

    Ultrasound contrast agents (UCAs) are encapsulated microbubbles that provide a source for acoustic impedance mismatch with the blood, due to difference in compressibility between the gas contained within these microbubbles and the blood. When insonified by an ultrasound beam, these UCAs act as nonlinear scatterers and enhance the echoes of the incident pulse, resulting in scattering of the incident ultrasound beam and emission of fundamental (f0), subharmonic (f0/2), harmonic (n*f0; n ∈ N) and ultraharmonic (((2n-1)/2)*f0; n ∈ N & n > 1) components in the echo response. A promising approach to monitor in vivo pressures revolves around the fact that the ultrasound transmit and receive parameters can be selected to induce an ambient pressure amplitude dependent subharmonic signal. This subharmonic signal may be used to estimate ambient pressure amplitude; such technique of estimating ambient pressure amplitude is referred to as subharmonic aided pressure estimation or SHAPE. This project develops and evaluates the feasibility of SHAPE to noninvasively monitor cardiac and hepatic pressures (using commercially available ultrasound scanners and UCAs) because invasive catheter based pressure measurements are used currently for these applications. Invasive catheter based pressure measurements pose risk of introducing infection while the catheter is guided towards the region of interest in the body through a percutaneous incision, pose risk of death due to structural or mechanical failure of the catheter (which has also triggered product recalls by the USA Food and Drug Administration) and may potentially modulate the pressures that are being measured. Also, catheterization procedures require fluoroscopic guidance to advance the catheter to the site of pressure measurements and such catheterization procedures are not performed in all clinical centers. Thus, a noninvasive technique to obtain ambient pressure values without the catheterization process is clinically

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

    Directory of Open Access Journals (Sweden)

    Eleni Papadopoulou

    2016-03-01

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

  13. Using cell phone location to assess misclassification errors in air pollution exposure estimation.

    Science.gov (United States)

    Yu, Haofei; Russell, Armistead; Mulholland, James; Huang, Zhijiong

    2018-02-01

    Air pollution epidemiologic and health impact studies often rely on home addresses to estimate individual subject's pollution exposure. In this study, we used detailed cell phone location data, the call detail record (CDR), to account for the impact of spatiotemporal subject mobility on estimates of ambient air pollutant exposure. This approach was applied on a sample with 9886 unique simcard IDs in Shenzhen, China, on one mid-week day in October 2013. Hourly ambient concentrations of six chosen pollutants were simulated by the Community Multi-scale Air Quality model fused with observational data, and matched with detailed location data for these IDs. The results were compared with exposure estimates using home addresses to assess potential exposure misclassification errors. We found the misclassifications errors are likely to be substantial when home location alone is applied. The CDR based approach indicates that the home based approach tends to over-estimate exposures for subjects with higher exposure levels and under-estimate exposures for those with lower exposure levels. Our results show that the cell phone location based approach can be used to assess exposure misclassification error and has the potential for improving exposure estimates in air pollution epidemiology studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A pilot study of the relationship between Doppler-estimated carotid and brachial artery flow and cardiac index.

    Science.gov (United States)

    Weber, U; Glassford, N J; Eastwood, G M; Bellomo, R; Hilton, A K

    2015-10-01

    We measured carotid and brachial artery blood flow by Doppler ultrasound in 11 human volunteers, and related these to cardiac index and to each other. The median (IQR [range]) carotid arterial blood flow was 0.334 (0.223-0.381 [0.052-0.563]) l.min(-1) on the right and 0.315 (0.223-0.369 [0.061-0.690]) l.min(-1) on the left. The brachial arterial blood flow was 0.049 (0.033-0.062 [0.015-0.204]) l.min(-1) on the right and 0.039 (0.027-0.054 [0.011-0.116]) on the left. Cardiac index was 3.2 (2.8-3.5 [1.9-5.4]) l.min(-1) .m(-2) . There was a moderate to good correlation between right-and left-sided flows (brachial: ρ = 0.45; carotid: ρ = 0.567). Brachial and carotid flow had no or a negative correlation with cardiac index (right brachial: ρ = -0.145, left brachial: ρ = -0.349; right carotid: ρ = -0.376, left carotid: ρ = -0.285). In contrast to some previous studies, we found that Doppler-estimated peripheral arterial blood flows only show a weak correlation with cardiac index and cannot be used to provide non-invasive estimates of cardiac index in man. © 2015 The Association of Anaesthetists of Great Britain and Ireland.

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

    International Nuclear Information System (INIS)

    Stocker, H.

    1981-10-01

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

  16. Negative control exposure studies in the presence of measurement error: implications for attempted effect estimate calibration.

    Science.gov (United States)

    Sanderson, Eleanor; Macdonald-Wallis, Corrie; Davey Smith, George

    2018-04-01

    Negative control exposure studies are increasingly being used in epidemiological studies to strengthen causal inference regarding an exposure-outcome association when unobserved confounding is thought to be present. Negative control exposure studies contrast the magnitude of association of the negative control, which has no causal effect on the outcome but is associated with the unmeasured confounders in the same way as the exposure, with the magnitude of the association of the exposure with the outcome. A markedly larger effect of the exposure on the outcome than the negative control on the outcome strengthens inference that the exposure has a causal effect on the outcome. We investigate the effect of measurement error in the exposure and negative control variables on the results obtained from a negative control exposure study. We do this in models with continuous and binary exposure and negative control variables using analysis of the bias of the estimated coefficients and Monte Carlo simulations. Our results show that measurement error in either the exposure or negative control variables can bias the estimated results from the negative control exposure study. Measurement error is common in the variables used in epidemiological studies; these results show that negative control exposure studies cannot be used to precisely determine the size of the effect of the exposure variable, or adequately adjust for unobserved confounding; however, they can be used as part of a body of evidence to aid inference as to whether a causal effect of the exposure on the outcome is present.

  17. Staff and patient exposure to X-ray radiation during cardiac procedures

    International Nuclear Information System (INIS)

    Jankowski, J.; Papierz, D.; Domienik, J.; Kacprzyk, J.; Tybor-Czerwinska, M.; Werduch, A.

    2008-01-01

    The aim of this study was to define and compare staff and patient doses during the most common types of cardiac procedures. The influence of operators' technique and quality of X-ray unit in use on doses received by the staff and patients was investigated. The study was conduced in two independent hemodynamic rooms (I and II). The doses to hand for medical staff (operators and nurses) were monitored. For hand dose assessment, ring thermoluminescent dosimeters were used. Regarding patient dosimetry, dose-area product was collected for selected procedures. The monthly hand doses ranged from 0.4 mSv to 41.2 mSv in room I and from 0.1 to 8.95 mSv in room II. On the basis of the above measurements, the annual doses were estimated. The maximum annual hand doses for the operator and for the nurse in room I were 232.8 mSv/year and 11.5 mSv/year and in room II - 29.8 mSv/year and 14.1 mSv/year, respectively. Additionally, to compare the doses received by the particular medical operators, the doses were normalized to the total workload. Hand dose per procedure ranged from 109 to 614 μSv/procedure and were significantly larger in room I. The typical DAP values (median) recorded for the CA and CA+PTCA procedures were 55 Gy/cm 2 and 171 Gy/cm 2 in room I and 35 Gy/cm 2 and 87 Gy/cm 2 in the room II, respectively. As a result of this survey, the impact of medical operator's experience as well as technique and quality of available X-ray units on doses received by staff and patients has been proven. On the basis of the above results, the special need for monitoring hand doses for medical staff, apart from the effective dose, has been recognized. (author)

  18. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958

    Energy Technology Data Exchange (ETDEWEB)

    Anspaugh, L.R.; Church, B.W.

    1985-12-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, Utah; Ely, Nevada; and Las Vegas, Nevada. Three events, HARRY (May 19, 1953), BEE (March 22, 1955), and SMOKY (August 31, 1957), accounted for over half of the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of ''infinite exposure,'' ''estimated exposure,'' and ''one year effective biological exposure'' are explained. 4 figs., 7 tabs.

  19. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958

    International Nuclear Information System (INIS)

    Anspaugh, L.R.; Church, B.W.

    1986-01-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, UT; Ely, NV; and Las Vegas, NV. Three events, HARRY (19 May 1953), BEE (22 March 1955), and SMOKY (31 August 1957), accounted for more than half the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of infinite exposure, estimated exposure, and 1-yr effective biological exposure are explained

  20. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958

    International Nuclear Information System (INIS)

    Anspaugh, L.R.; Church, B.W.

    1985-12-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, Utah; Ely, Nevada; and Las Vegas, Nevada. Three events, HARRY (May 19, 1953), BEE (March 22, 1955), and SMOKY (August 31, 1957), accounted for over half of the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of ''infinite exposure,'' ''estimated exposure,'' and ''one year effective biological exposure'' are explained. 4 figs., 7 tabs

  1. Radiation dose in cardiac SPECT/CT: An estimation of SSDE and effective dose

    International Nuclear Information System (INIS)

    Abdollahi, Hamid; Shiri, Isaac; Salimi, Yazdan; Sarebani, Maghsoud; Mehdinia, Reza; Deevband, Mohammad Reza; Mahdavi, Seied Rabi; Sohrabi, Ahmad; Bitarafan-Rajabi, Ahmad

    2016-01-01

    Aims: The dose levels for Computed Tomography (CT) localization and attenuation correction of Single Photon Emission Computed Tomography (SPECT) are limited and reported as Volume Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP). This work presents CT dose estimation from Cardiac SPECT/CT based on new American Association of Physicists in Medicine (AAPM) Size Specific Dose Estimation (SSDE) parameter, effective dose, organ doses and also emission dose from nuclear issue. Material and methods: Myocardial perfusion SPECT/CT for 509 patients was included in the study. SSDE, effective dose and organ dose were calculated using AAPM guideline and Impact-Dose software. Data were analyzed using R and SPSS statistical software. Spearman-Pearson correlation test and linear regression models were used for finding correlations and relationships among parameters. Results: The mean CTDIvol was 1.34 mGy ± 0.19 and the mean SSDE was 1.7 mGy ± 0.16. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The spearman test showed that correlation between body size and organ doses is significant except thyroid and red bone marrow. CTDIvol was strongly dependent on patient size, but SSDE was not. Emission dose was strongly dependent on patient weight, but its dependency was lower to effective diameter. Conclusion: The dose parameters including CTDIvol, DLP, SSDE, effective dose values reported here are very low and below the reference level. This data suggest that appropriate CT acquisition parameters in SPECT/CT localization and attenuation correction are very beneficial for patients and lowering cancer risks.

  2. Radiation dose in cardiac SPECT/CT: An estimation of SSDE and effective dose

    Energy Technology Data Exchange (ETDEWEB)

    Abdollahi, Hamid, E-mail: Hamid_rbp@yahoo.com [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shiri, Isaac [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Salimi, Yazdan [Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sarebani, Maghsoud; Mehdinia, Reza [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Deevband, Mohammad Reza [Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mahdavi, Seied Rabi [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Radiation Biology Research Center, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sohrabi, Ahmad [Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bitarafan-Rajabi, Ahmad, E-mail: bitarafan@hotmail.com [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Nuclear Medicine, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-12-15

    Aims: The dose levels for Computed Tomography (CT) localization and attenuation correction of Single Photon Emission Computed Tomography (SPECT) are limited and reported as Volume Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP). This work presents CT dose estimation from Cardiac SPECT/CT based on new American Association of Physicists in Medicine (AAPM) Size Specific Dose Estimation (SSDE) parameter, effective dose, organ doses and also emission dose from nuclear issue. Material and methods: Myocardial perfusion SPECT/CT for 509 patients was included in the study. SSDE, effective dose and organ dose were calculated using AAPM guideline and Impact-Dose software. Data were analyzed using R and SPSS statistical software. Spearman-Pearson correlation test and linear regression models were used for finding correlations and relationships among parameters. Results: The mean CTDIvol was 1.34 mGy ± 0.19 and the mean SSDE was 1.7 mGy ± 0.16. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The spearman test showed that correlation between body size and organ doses is significant except thyroid and red bone marrow. CTDIvol was strongly dependent on patient size, but SSDE was not. Emission dose was strongly dependent on patient weight, but its dependency was lower to effective diameter. Conclusion: The dose parameters including CTDIvol, DLP, SSDE, effective dose values reported here are very low and below the reference level. This data suggest that appropriate CT acquisition parameters in SPECT/CT localization and attenuation correction are very beneficial for patients and lowering cancer risks.

  3. Estimating diesel fuel exposure for a plumber repairing an underground pipe.

    Science.gov (United States)

    Finn, Mary; Stenzel, Mark; Ramachandran, Gurumurthy

    2017-04-01

    We estimated the diesel fuel exposure of a plumber repairing an underground water line leak at a truck stop. The repair work was performed over three days during which the plumber spent most of his time in a pit filled with a mixture of water and diesel fuel. Thus, the plumber was exposed via both the inhalation and dermal routes. While previously asymptomatic, he was diagnosed with acute renal failure 35 days after working at this site. No measurements were available for estimating either inhalation or dermal exposures or the cumulative dose and, therefore, two different approaches were used that were based on simple models of the exposure scenario. The first approach used the ideal gas law with the vapor pressure of the diesel fuel mixture to estimate a saturation vapor concentration, while the second one used a mass balance of the petroleum hydrocarbon component of diesel fuel in conjunction with the Henry's Law constant for this mixture. These inhalation exposure estimates were then adjusted to account for the limited ventilation in a confined space. The inhalation exposure concentrations predicted when handling the water layer alone is much lower than that expected from the organic layer. This case study illustrates the large differences in inhalation exposure associated with volatile organic layers and aqueous solution containing these chemicals. The estimate of dermal exposure was negligible compared to the inhalation exposure because the skin presents a much smaller surface area of exposure to the contaminant compared to the lungs. The methodology presented here is useful for situations where little information is available for more formal mathematical exposure modeling, but where adjustments to the worst-case exposures, estimated simply, can provide reasonable exposure estimates.

  4. Estimation methods with ordered exposure subject to measurement error and missingness in semi-ecological design

    Directory of Open Access Journals (Sweden)

    Kim Hyang-Mi

    2012-09-01

    Full Text Available Abstract Background In epidemiological studies, it is often not possible to measure accurately exposures of participants even if their response variable can be measured without error. When there are several groups of subjects, occupational epidemiologists employ group-based strategy (GBS for exposure assessment to reduce bias due to measurement errors: individuals of a group/job within study sample are assigned commonly to the sample mean of exposure measurements from their group in evaluating the effect of exposure on the response. Therefore, exposure is estimated on an ecological level while health outcomes are ascertained for each subject. Such study design leads to negligible bias in risk estimates when group means are estimated from ‘large’ samples. However, in many cases, only a small number of observations are available to estimate the group means, and this causes bias in the observed exposure-disease association. Also, the analysis in a semi-ecological design may involve exposure data with the majority missing and the rest observed with measurement errors and complete response data collected with ascertainment. Methods In workplaces groups/jobs are naturally ordered and this could be incorporated in estimation procedure by constrained estimation methods together with the expectation and maximization (EM algorithms for regression models having measurement error and missing values. Four methods were compared by a simulation study: naive complete-case analysis, GBS, the constrained GBS (CGBS, and the constrained expectation and maximization (CEM. We illustrated the methods in the analysis of decline in lung function due to exposures to carbon black. Results Naive and GBS approaches were shown to be inadequate when the number of exposure measurements is too small to accurately estimate group means. The CEM method appears to be best among them when within each exposure group at least a ’moderate’ number of individuals have their

  5. Estimating cost-effectiveness of mass cardiopulmonary resuscitation training strategies to improve survival from cardiac arrest in private locations.

    Science.gov (United States)

    Swor, Robert; Compton, Scott

    2004-01-01

    Most cardiopulmonary resuscitation (CPR) trainees are young, and most cardiac arrests occur in private residences witnessed by older individuals. To estimate the cost-effectiveness of a CPR training program targeted at citizens over the age of 50 years compared with that of current nontargeted public CPR training. A model was developed using cardiac arrest and known demographic data from a single suburban zip code (population 36,325) including: local data (1997-1999) regarding cardiac arrest locations (public vs. private); incremental survival with CPR (historical survival rate 7.8%, adjusted odds ratio for CPR 2.0); arrest bystander demographics obtained from bystander telephone interviews; zip code demographics regarding population age and distribution; and 12.50 dollars per student for the cost of CPR training. Published rates of CPR training programs by age were used to estimate the numbers typically trained. Several assumptions were made: 1) there would be one bystander per. arrest; 2) the bystander would always perform CPR if trained; 3) cardiac arrest would be evenly distributed in the population; and 4) CPR training for a proportion of the population would proportionally increase CPR provision. Rates of arrest, bystanders by age, number of CPR trainees needed to result in increased arrest survival, and training cost per life saved for a one-year study period were calculated. There were 24.3 cardiac arrests per year, with 21.9 (90%) occurring in homes. In 66.5% of the home arrests, the bystander was more than 50 years old. To yield one additional survivor using the current CPR training strategy, 12,306 people needed to be trained (3,510 bystanders aged 50 years), which resulted in CPR provision to 7.14 additional patients. The training cost per life saved for a bystander aged 50 years was 785,040 dollars. Using a strategy of training only those cost of 53,383 dollars per life saved. Using these assumptions, current CPR training strategy is not a cost

  6. Ionizing radiation exposure of LDEF (pre-recovery estimates)

    Science.gov (United States)

    Benton, E. V.; Heinrich, W.; Parnell, T. A.; Armstrong, T. W.; Derrickson, J. H.; Fishman, G. J.; Frank, A. L.; Watts, J. W. Jr; Wiegel, B.

    1992-01-01

    The long duration exposure facility (LDEF), launched into a 258 nautical mile orbit with an inclination of 28.5 degrees, remained in space for nearly 6 yr. The 21,500 lb NASA satellite was one of the largest payloads ever deployed by the Space Shuttle. LDEF completed 32,422 orbits and carried 57 major experiments representing more than 200 investigators from 33 private companies, 21 universities and nine countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures and power and propulsion. A number of the experiments were specifically designed to measure the radiation environment. These experiments are of specific interest, since the LDEF orbit is essentially the same as that of the Space Station Freedom. Consequently, the radiation measurements on LDEF will play a significant role in the design of radiation shielding of the space station. The contributions of the various authors presented here attempt to predict the major aspects of the radiation exposure received by the various LDEF experiments and therefore should be helpful to investigators who are in the process of analyzing experiments which may have been affected by exposure to ionizing radiation. The paper discusses the various types and sources of ionizing radiation including cosmic rays, trapped particles (both protons and electrons) and secondary particles (including neutrons, spallation products and high-LET recoils), as well as doses and LET spectra as a function of shielding. Projections of the induced radioactivity of LDEF are also discussed.

  7. Comparing the Advanced REACH Tool's (ART) Estimates With Switzerland's Occupational Exposure Data.

    Science.gov (United States)

    Savic, Nenad; Gasic, Bojan; Schinkel, Jody; Vernez, David

    2017-10-01

    The Advanced REACH Tool (ART) is the most sophisticated tool used for evaluating exposure levels under the European Union's Registration, Evaluation, Authorisation and restriction of CHemicals (REACH) regulations. ART provides estimates at different percentiles of exposure and within different confidence intervals (CIs). However, its performance has only been tested on a limited number of exposure data. The present study compares ART's estimates with exposure measurements collected over many years in Switzerland. Measurements from 584 cases of exposure to vapours, mists, powders, and abrasive dusts (wood/stone and metal) were extracted from a Swiss database. The corresponding exposures at the 50th and 90th percentiles were calculated in ART. To characterize the model's performance, the 90% CI of the estimates was considered. ART's performance at the 50th percentile was only found to be insufficiently conservative with regard to exposure to wood/stone dusts, whereas the 90th percentile showed sufficient conservatism for all the types of exposure processed. However, a trend was observed with the residuals, where ART overestimated lower exposures and underestimated higher ones. The median was more precise, however, and the majority (≥60%) of real-world measurements were within a factor of 10 from ART's estimates. We provide recommendations based on the results and suggest further, more comprehensive, investigations. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  8. Integrating travel behavior with land use regression to estimate dynamic air pollution exposure in Hong Kong.

    Science.gov (United States)

    Tang, Robert; Tian, Linwei; Thach, Thuan-Quoc; Tsui, Tsz Him; Brauer, Michael; Lee, Martha; Allen, Ryan; Yuchi, Weiran; Lai, Poh-Chin; Wong, Paulina; Barratt, Benjamin

    2018-04-01

    Epidemiological studies typically use subjects' residential address to estimate individuals' air pollution exposure. However, in reality this exposure is rarely static as people move from home to work/study locations and commute during the day. Integrating mobility and time-activity data may reduce errors and biases, thereby improving estimates of health risks. To incorporate land use regression with movement and building infiltration data to estimate time-weighted air pollution exposures stratified by age, sex, and employment status for population subgroups in Hong Kong. A large population-representative survey (N = 89,385) was used to characterize travel behavior, and derive time-activity pattern for each subject. Infiltration factors calculated from indoor/outdoor monitoring campaigns were used to estimate micro-environmental concentrations. We evaluated dynamic and static (residential location-only) exposures in a staged modeling approach to quantify effects of each component. Higher levels of exposures were found for working adults and students due to increased mobility. Compared to subjects aged 65 or older, exposures to PM 2.5 , BC, and NO 2 were 13%, 39% and 14% higher, respectively for subjects aged below 18, and 3%, 18% and 11% higher, respectively for working adults. Exposures of females were approximately 4% lower than those of males. Dynamic exposures were around 20% lower than ambient exposures at residential addresses. The incorporation of infiltration and mobility increased heterogeneity in population exposure and allowed identification of highly exposed groups. The use of ambient concentrations may lead to exposure misclassification which introduces bias, resulting in lower effect estimates than 'true' exposures. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Investigation of influence of 16-slice spiral CT electrocardiogram-controlled dose modulation on exposure dosage and image quality of cardiac CT imaging under simulated fluctuant heart rate

    International Nuclear Information System (INIS)

    Yin Yan; Chen Jie; Chai Weiming; Hua Jia; Gao Na; Xu Jianrong; Shen Yun

    2008-01-01

    Objective: To investigate the influence of electrocardiogram (ECG)-controlled dose modulation on exposure dosage and image quality of cardiac CT imaging in a cardiac phantom with simulated fluctuant heart rate. Methods: The basal heart rate of the cardiac pulsating phantom was set as 60 bpm, the experimental situations were divided as 6 groups according to different heart rates. The cardiac imaging was performed on the cardiac phantom when the ECG-controlled dose modulation was firstly turned off. The exposure dosage of each scan sequence was documented. The standard deviation of the CT values of the phantom was measured on the central slice after coronal reformation of the raw data. The quality of 2D and 3D images were scored. Then cardiac imaging was performed when ECG modulation was on and set as four groups according to different modulation parameters. All the data were documented as before. The results from the five groups with and without ECG modulation current were analyzed by F test and comparative rank sum test using the statistical software SPSS 10.0. Results: Statistical analysis showed no significant difference (P>0.05) between the SNR of images (SD value was 27.78 and 26.30) from the groups that full mA output at wide reconstruction phase (69%-99%) when the heart rate was fluctuant(≥7.5 bpm). There was also no significant difference (P>0.05) between the quality of the 2D and 3D images. But there was a significant difference (P 12.5 bpm, the exposure dosage would increase obviously (from 0.6 to 1.7 mSv). Conclusion: For cardiac imaging with 16-slice row CT, the application of ECG modulated current can effectively reduce the exposure dosage without compromising the image quality even if heart rate was fluctuant. (authors)

  10. Estimates of radiation doses from various sources of exposure

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter provides an overview of radiation doses to individuals and to the collective US population from various sources of ionizing radiation. Summary tables present doses from various sources of ionizing radiation. Summary tables present doses from occupational exposures and annual per capita doses from natural background, the healing arts, nuclear weapons, nuclear energy and consumer products. Although doses from non-ionizing radiation are not as yet readily available in a concise form, the major sources of non-ionizing radiation are listed

  11. Exposure to low dose benzo[a]pyrene during early life stages causes symptoms similar to cardiac hypertrophy in adult zebrafish.

    Science.gov (United States)

    Huang, Lixing; Gao, Dongxu; Zhang, Youyu; Wang, Chonggang; Zuo, Zhenghong

    2014-07-15

    Growing evidence indicates that polycyclic aromatic hydrocarbons (PAHs) can lead to cardiac hypertrophy and recent research indicates that exposure to low dose crude oil during early embryonic development may lead to impacts on heart health at later life stages. The aim of this study was to evaluate whether exposure during early life stages to low dose benzo[a]pyrene (BaP), as a high-ring PAH, would lead to cardiac hypertrophy at later life stages. Zebrafish were exposed to low dose BaP until 96 hpf, then transferred to clean water and maintained for a year before histological and molecular biological analysis. Our results showed that exposure to low level BaP during early life stages increased heart weight to body weight ratios and deposited collagen in the heart of adult zebrafish. ANP, BNP and c-Myc were also induced in the heart of adult zebrafish by BaP. These results proved that low level BaP exposure during early life stages caused symptoms similar to cardiac hypertrophy in adult zebrafish. Our results displayed an elevated expression of CdC42, RhoA, p-ERK1, 2 and Rac1. Therefore, the mechanism of the cardiac hypertrophy caused by BaP exposure during early life stages may be through inducing the expression of CdC42, RhoA and Rac1, together with activating ERK1, 2. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Estimation of the displacement of cardiac substructures and the motion of the coronary arteries using electrocardiographic gating

    Directory of Open Access Journals (Sweden)

    Tan W

    2013-09-01

    differ significantly between men and women. Conclusion: Most average displacements of the cardiac substructures and coronary arteries were 3–8 mm in three dimensions. These findings will be useful to accurately estimate the radiation dose to cardiac substructures during thoracic radiation and to evaluate the risk of radiation-related heart disease. Keywords: coronary artery, organ motion/displacement, radiotherapy, heart disease

  13. Predictive framework for estimating exposure of birds to pharmaceuticals.

    Science.gov (United States)

    Bean, Thomas G; Arnold, Kathryn E; Lane, Julie M; Bergström, Ed; Thomas-Oates, Jane; Rattner, Barnett A; Boxall, Alistair B A

    2017-09-01

    We present and evaluate a framework for estimating concentrations of pharmaceuticals over time in wildlife feeding at wastewater treatment plants (WWTPs). The framework is composed of a series of predictive steps involving the estimation of pharmaceutical concentration in wastewater, accumulation into wildlife food items, and uptake by wildlife with subsequent distribution into, and elimination from, tissues. Because many pharmacokinetic parameters for wildlife are unavailable for the majority of drugs in use, a read-across approach was employed using either rodent or human data on absorption, distribution, metabolism, and excretion. Comparison of the different steps in the framework against experimental data for the scenario where birds are feeding on a WWTP contaminated with fluoxetine showed that estimated concentrations in wastewater treatment works were lower than measured concentrations; concentrations in food could be reasonably estimated if experimental bioaccumulation data are available; and read-across from rodent data worked better than human to bird read-across. The framework provides adequate predictions of plasma concentrations and of elimination behavior in birds but yields poor predictions of distribution in tissues. The approach holds promise, but it is important that we improve our understanding of the physiological similarities and differences between wild birds and domesticated laboratory mammals used in pharmaceutical efficacy/safety trials, so that the wealth of data available can be applied more effectively in ecological risk assessments. Environ Toxicol Chem 2017;36:2335-2344. © 2017 SETAC. © 2017 SETAC.

  14. Predictive framework for estimating exposure of birds to pharmaceuticals

    Science.gov (United States)

    Bean, Thomas G.; Arnold, Kathryn E.; Lane, Julie M.; Bergström, Ed; Thomas-Oates, Jane; Rattner, Barnett A.; Boxall, Allistair B.A.

    2017-01-01

    We present and evaluate a framework for estimating concentrations of pharmaceuticals over time in wildlife feeding at wastewater treatment plants (WWTPs). The framework is composed of a series of predictive steps involving the estimation of pharmaceutical concentration in wastewater, accumulation into wildlife food items, and uptake by wildlife with subsequent distribution into, and elimination from, tissues. Because many pharmacokinetic parameters for wildlife are unavailable for the majority of drugs in use, a read-across approach was employed using either rodent or human data on absorption, distribution, metabolism, and excretion. Comparison of the different steps in the framework against experimental data for the scenario where birds are feeding on a WWTP contaminated with fluoxetine showed that estimated concentrations in wastewater treatment works were lower than measured concentrations; concentrations in food could be reasonably estimated if experimental bioaccumulation data are available; and read-across from rodent data worked better than human to bird read-across. The framework provides adequate predictions of plasma concentrations and of elimination behavior in birds but yields poor predictions of distribution in tissues. The approach holds promise, but it is important that we improve our understanding of the physiological similarities and differences between wild birds and domesticated laboratory mammals used in pharmaceutical efficacy/safety trials, so that the wealth of data available can be applied more effectively in ecological risk assessments.

  15. Protocols of radiocontaminant air monitoring for inhalation exposure estimates

    International Nuclear Information System (INIS)

    Shinn, J.H.

    1995-09-01

    Monitoring the plutonium and americium particle emissions from soils contaminated during atmospheric nuclear testing or due to accidental releases is important for several reasons. First, it is important to quantify the extent of potential human exposure from inhalation of alpha-emitting particles, which is the major exposure pathway from transuranic radionuclides. Second, the information provided by resuspension monitoring is the basis of criteria that determine the target soil concentrations for management and cleanup of contaminated soil sites. There are other radioactive aerosols, such as the fission products (cesium and strontium) and neutron-activation products (europium isotopes), which may be resuspended and therefore necessary to monitor as well. This Standard Protocol (SP) provides the method used for radiocontaminant air monitoring by the Health and Ecological Assessment Division (formerly Environmental Sciences Division), Lawrence Livermore National Laboratory, as developed and tested at Nevada Test Site (NTS) and in the Marshall Islands. The objective of this SP is to document the applications and methods of monitoring of all the relevant variables. This protocol deals only with measuring air concentrations of radionuclides and total suspended particulates (TSP, or open-quotes dustclose quotes). A separate protocol presents the more difficult measurements required to determine transuranic aerosol emission rates, or open-quotes resuspension rateclose quotes

  16. Use of an aggregate exposure model to estimate consumer exposure to fragrance ingredients in personal care and cosmetic products.

    Science.gov (United States)

    Safford, B; Api, A M; Barratt, C; Comiskey, D; Daly, E J; Ellis, G; McNamara, C; O'Mahony, C; Robison, S; Smith, B; Thomas, R; Tozer, S

    2015-08-01

    Ensuring the toxicological safety of fragrance ingredients used in personal care and cosmetic products is essential in product development and design, as well as in the regulatory compliance of the products. This requires an accurate estimation of consumer exposure which, in turn, requires an understanding of consumer habits and use of products. Where ingredients are used in multiple product types, it is important to take account of aggregate exposure in consumers using these products. This publication investigates the use of a newly developed probabilistic model, the Creme RIFM model, to estimate aggregate exposure to fragrance ingredients using the example of 2-phenylethanol (PEA). The output shown demonstrates the utility of the model in determining systemic and dermal exposure to fragrances from individual products, and aggregate exposure. The model provides valuable information not only for risk assessment, but also for risk management. It should be noted that data on the concentrations of PEA in products used in this article were obtained from limited sources and not the standard, industry wide surveys typically employed by the fragrance industry and are thus presented here to illustrate the output and utility of the newly developed model. They should not be considered an accurate representation of actual exposure to PEA. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Influence of heart motion on cardiac output estimation by means of electrical impedance tomography: a case study

    International Nuclear Information System (INIS)

    Proença, Martin; Braun, Fabian; Rapin, Michael; Solà, Josep; Lemay, Mathieu; Adler, Andy; Grychtol, Bartłomiej; Bohm, Stephan H; Thiran, Jean-Philippe

    2015-01-01

    Electrical impedance tomography (EIT) is a non-invasive imaging technique that can measure cardiac-related intra-thoracic impedance changes. EIT-based cardiac output estimation relies on the assumption that the amplitude of the impedance change in the ventricular region is representative of stroke volume (SV). However, other factors such as heart motion can significantly affect this ventricular impedance change. In the present case study, a magnetic resonance imaging-based dynamic bio-impedance model fitting the morphology of a single male subject was built. Simulations were performed to evaluate the contribution of heart motion and its influence on EIT-based SV estimation. Myocardial deformation was found to be the main contributor to the ventricular impedance change (56%). However, motion-induced impedance changes showed a strong correlation (r = 0.978) with left ventricular volume. We explained this by the quasi-incompressibility of blood and myocardium. As a result, EIT achieved excellent accuracy in estimating a wide range of simulated SV values (error distribution of 0.57 ± 2.19 ml (1.02 ± 2.62%) and correlation of r = 0.996 after a two-point calibration was applied to convert impedance values to millilitres). As the model was based on one single subject, the strong correlation found between motion-induced changes and ventricular volume remains to be verified in larger datasets. (paper)

  18. Probabilistic Reverse dOsimetry Estimating Exposure Distribution (PROcEED)

    Science.gov (United States)

    PROcEED is a web-based application used to conduct probabilistic reverse dosimetry calculations.The tool is used for estimating a distribution of exposure concentrations likely to have produced biomarker concentrations measured in a population.

  19. Energy expenditure estimation in beta-blocker-medicated cardiac patients by combining heart rate and body movement data.

    Science.gov (United States)

    Kraal, Jos J; Sartor, Francesco; Papini, Gabriele; Stut, Wim; Peek, Niels; Kemps, Hareld Mc; Bonomi, Alberto G

    2016-11-01

    Accurate assessment of energy expenditure provides an opportunity to monitor physical activity during cardiac rehabilitation. However, the available assessment methods, based on the combination of heart rate (HR) and body movement data, are not applicable for patients using beta-blocker medication. Therefore, we developed an energy expenditure prediction model for beta-blocker-medicated cardiac rehabilitation patients. Sixteen male cardiac rehabilitation patients (age: 55.8 ± 7.3 years, weight: 93.1 ± 11.8 kg) underwent a physical activity protocol with 11 low- to moderate-intensity common daily life activities. Energy expenditure was assessed using a portable indirect calorimeter. HR and body movement data were recorded during the protocol using unobtrusive wearable devices. In addition, patients underwent a symptom-limited exercise test and resting metabolic rate assessment. Energy expenditure estimation models were developed using multivariate regression analyses based on HR and body movement data and/or patient characteristics. In addition, a HR-flex model was developed. The model combining HR and body movement data and patient characteristics showed the highest correlation and lowest error (r 2  = 0.84, root mean squared error = 0.834 kcal/minute) with total energy expenditure. The method based on individual calibration data (HR-flex) showed lower accuracy (i 2  = 0.83, root mean squared error = 0.992 kcal/minute). Our results show that combining HR and body movement data improves the accuracy of energy expenditure prediction models in cardiac patients, similar to methods that have been developed for healthy subjects. The proposed methodology does not require individual calibration and is based on the data that are available in clinical practice. © The European Society of Cardiology 2016.

  20. Prenatal exposure to dexamethasone in the mouse alters cardiac growth patterns and increases pulse pressure in aged male offspring.

    Directory of Open Access Journals (Sweden)

    Lee O'Sullivan

    Full Text Available Exposure to synthetic glucocorticoids during development can result in later cardiovascular and renal disease in sheep and rats. Although prenatal glucocorticoid exposure is associated with impaired renal development, less is known about effects on the developing heart. This study aimed to examine the effects of a short-term exposure to dexamethasone (60 hours from embryonic day 12.5 on the developing mouse heart, and cardiovascular function in adult male offspring. Dexamethasone (DEX exposed fetuses were growth restricted compared to saline treated controls (SAL at E14.5, but there was no difference between groups at E17.5. Heart weights of the DEX fetuses also tended to be smaller at E14.5, but not different at E17.5. Cardiac AT1aR, Bax, and IGF-1 mRNA expression was significantly increased by DEX compared to SAL at E17.5. In 12-month-old offspring DEX exposure caused an increase in basal blood pressure of ~3 mmHg. In addition, DEX exposed mice had a widened pulse pressure compared to SAL. DEX exposed males at 12 months had an approximate 25% reduction in nephron number compared to SAL, but no difference in cardiomyocyte number. Exposure to DEX in utero appears to adversely impact on nephrogenesis and heart growth but is not associated with a cardiomyocyte deficit in male mice in adulthood, possibly due to compensatory growth of the myocardium following the initial insult. However, the widened pulse pressure may be indicative of altered vascular compliance.

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

    Science.gov (United States)

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

  2. EPA's SHEDS-multimedia model: children's cumulative pyrethroid exposure estimates and evaluation against NHANES biomarker data

    Science.gov (United States)

    The U.S. EPA's SHEDS-Multimedia model was applied to enhance the understanding of children's exposures and doses to multiple pyrethroid pesticides, including major contributing chemicals and pathways. This paper presents combined dietary and residential exposure estimates and cum...

  3. Studies on the reference Korean and estimation of radiation exposure dose

    International Nuclear Information System (INIS)

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

    1982-01-01

    For the purpose of establishment of Reference Korean and estimation of internal and external exposure doses in the Reference Korean, we have surveyed reference values for Koreans such as physical standards including height, weight, and body surface area, food consumption rate of daily intake of radioactive substances and exposure dose from natural radiation. (Author)

  4. External exposure estimates for individuals near the Nevada Test Site

    International Nuclear Information System (INIS)

    Henderson, R.W.; Smale, R.F.

    1987-01-01

    Individuals living near the Nevada Test Site were exposed to both beta and gamma radiations from fission products and activation products resulting from the atmospheric testing of nuclear devices. These exposures were functions of the amount of material deposited, the time of arrival of the debris, and the amount of shielding afforded by structures. Results are presented for each of nine generic life styles. These are representative of the living patterns of the people residing in the area. For each event at each location for which data exist, a representative of each life style was closely followed for a period of thirty days. The results of these detailed calculations are then extrapolated to the present. 7 refs., 5 figs., 2 tabs

  5. Out-of-hospital cardiac arrests and outdoor air pollution exposure in Copenhagen, Denmark.

    Directory of Open Access Journals (Sweden)

    Janine Wichmann

    Full Text Available Cardiovascular disease is the number one cause of death globally and air pollution can be a contributing cause. Acute myocardial infarction and cardiac arrest are frequent manifestations of coronary heart disease. The objectives of the study were to investigate the association between 4 657 out-of-hospital cardiac arrests (OHCA and hourly and daily outdoor levels of PM(10, PM(2.5, coarse fraction of PM (PM(10-2.5, ultrafine particle proxies, NO(x, NO(2, O(3 and CO in Copenhagen, Denmark, for the period 2000-2010. Susceptible groups by age and sex was also investigated. A case-crossover design was applied. None of the hourly lags of any of the pollutants were significantly associated with OHCA events. The strongest association with OHCA events was observed for the daily lag4 of PM(2.5, lag3 of PM(10, lag3 of PM(10-2.5, lag3 of NO(x and lag4 of CO. An IQR increase of PM(2.5 and PM(10 was associated with a significant increase of 4% (95% CI: 0%; 9% and 5% (95% CI: 1%; 9% in OHCA events with 3 days lag, respectively. None of the other daily lags or other pollutants was significantly associated with OHCA events. Adjustment for O(3 slightly increased the association between OHCA and PM(2.5 and PM(10. No susceptible groups were identified.

  6. Ozone co-exposure modifies cardiac function responses to fine and ultrafine particulate matter in mice

    Science.gov (United States)

    There is growing evidence from epidemiological studies that show acute exposure to particulate matter (PM) increases the risk of cardiovascular morbidity and mortality. Although the data supporting these findings are increasingly more convincing, the immediate impact of PM inhala...

  7. Estimating Exchange Rate Exposure over Various Return Horizons: Focusing on Major Countries in East Asia

    Directory of Open Access Journals (Sweden)

    Jeong Wook Lee

    2016-12-01

    Full Text Available In this paper, we estimate the exchange rate exposure, indicating the effect of exchange rate movements on firm values, for a sample of 1,400 firms in seven East Asian countries. The exposure estimates based on various exchange rate variables, return horizons and a control variable are compared. A key result from our analysis is that the long term effect of exchange rate movements on firm values is greater than the short term effect. And we find very similar results from using other exchange rate variables such as the U.S. dollar exchange rate, etc. Second, we add exchange rate volatility as a control variable and find that the extent of exposure is not much changed. Third, we examine the changes in exposure to exchange rate volatility with an increase in return horizon. Consequently the ratio of firms with significant exposures increases with the return horizons. Interestingly, the increase of exposure with the return horizons is faster for exposure to volatility than for exposure to exchange rate itself. Taken as a whole, our findings suggest that the so-called "exposure puzzle" may be a matter of the methodology used to measure exposure.

  8. Use of ubiquitous materials for the estimation of accidental exposures

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Kim, J.L.; Lee, J.I.

    2012-01-01

    Incidents involving unexpected radiation exposure do take place due to human error, equipment failure or other reasons in spite of regulatory systems being in place. Medical physicists who are also radiation safety officers (RSO) of their institutions in several countries, like India, have the responsibility of radiation protection of the staff, carers and comforters of the patients, visitors and public at large, apart from ensuring patient-specific treatment planning for accurate dose delivery, adoption of optimized practices, and minimization of chances of radiation accidents in radiation therapy, radio-diagnostic, and nuclear medicine practices. Theft and mishandling of 137 Cs teletherapy source in 1987 in Goiania (Brazil) in which 28 people suffered radiation burns and five people (three men, one woman, and one child) died and several other incidents demonstrated that mishandling of a source from a place like hospital cannot be ruled out. In the recent times, especially after terrorist attack on World Trade Center, New York, USA (on September 11, 2001), apprehensions of radiation terrorism and other malevolent uses (Dirty Bomb) of radioactive materials have considerably increased all over the world. To meet the situation of any radiation accident (due to external sources or the hospital-based sources), preparedness for dosimetry of the exposed persons in the quickest possible way becomes important for the implementation of the necessary follow-up procedures

  9. Long-term cognitive and cardiac outcomes after prenatal exposure to chemotherapy in children aged 18 months or older: an observational study.

    NARCIS (Netherlands)

    Amant, F.; Calsteren, K. van; Halaska, M.J.; Gziri, M.M.; Hui, W.; Lagae, L.; Willemsen, M.A.A.P.; Kapusta, L.; Calster, B. van; Wouters, H; Heyns, L.; Han, S.N.; Tomek, V.; Mertens, L.; Ottevanger, P.B.

    2012-01-01

    BACKGROUND: Chemotherapy for the treatment of maternal cancers during pregnancy has become more acceptable in the past decade; however, the effect of prenatal exposure to chemotherapy on cardiac and neurodevelopmental outcomes of the offspring is still uncertain. We aimed to record the general

  10. Transient receptor potential cation channel A1 (TRPA1) mediates decrements in cardiac mechanical function and dysrhythmia caused by a single air pollution exposure in mice

    Science.gov (United States)

    This work, which will be presented at SOT 2014, demonstrates that a single exposure to either ozone or acrolein causes decrements in cardiac function and altered electrical activity (i.e. arrhythmia). The results suggest that this effect is mediated by the airway sensor TRPA1. ...

  11. Trait anxiety mediates the effect of stress exposure on post-traumatic stress disorder and depression risk in cardiac surgery patients

    NARCIS (Netherlands)

    Kok, Lotte; Sep, Milou S; Veldhuijzen, Dieuwke S; Cornelisse, Sandra; Nierich, Arno P; van der Maaten, Joost; Rosseel, Peter M; Hofland, Jan; Dieleman, Jan M; Vinkers, Christiaan H; Joëls, Marian; van Dijk, Diederik; Hillegers, Manon H

    2016-01-01

    BACKGROUND: Post-traumatic stress disorder (PTSD) and depression are common after cardiac surgery. Lifetime stress exposure and personality traits may influence the development of these psychiatric conditions. METHODS: Self-reported rates of PTSD and depression and potential determinants (i.e.,

  12. Estimating the incidence of lung cancer attributable to occupational exposure in Iran

    Directory of Open Access Journals (Sweden)

    Mousavi-Jarrahi Yasaman

    2009-05-01

    Full Text Available Abstract Objective The aim of this study was to estimate the fraction of lung cancer incidence in Iran attributed to occupational exposures to the well-established lung cancer carcinogens, including silica, cadmium, nickel, arsenic, chromium, diesel fumes, beryllium, and asbestos. Methods Nationwide exposure to each of the mentioned carcinogens was estimated using workforce data from the Iranian population census of 1995, available from the International Labor Organization (ILO website. The prevalence of exposure to carcinogens in each industry was estimated using exposure data from the CAREX (CARcinogen EXposure database, an international occupational carcinogen information system kept and maintained by the European Union. The magnitude of the relative risk of lung cancer for each carcinogen was estimated from local and international literature. Using the Levin modified population attributable risk (incidence fraction, lung cancer incidence (as estimated by the Tehran Population-Based Cancer Registry attributable to workplace exposure to carcinogens was estimated. Results The total workforce in Iran according to the 1995 census identified 12,488,020 men and 677,469 women. Agriculture is the largest sector with 25% of the male and 0.27% of female workforce. After applying the CAREX exposure estimate to each sector, the proportion exposed to lung carcinogens was 0.08% for male workers and 0.02% for female workers. Estimating a relative risk of 1.9 (95% CI of 1.7–2.1 for high exposure and 1.3 (95% CI 1.2–1.4 for low exposure, and employing the Levin modified formula, the fraction of lung cancer attributed to carcinogens in the workplace was 1.5% (95% CI of 1.2–1.9 for females and 12% (95% CI of 10–15 for males. These fractions correspond to an estimated incidence of 1.3 and 0.08 cases of lung cancer per 100,000 population for males and females, respectively. Conclusion The incidence of lung cancer due to occupational exposure is low in

  13. Estimation of children's radiation dose from cardiac catheterisations, performed for the diagnosis or the treatment of a congenital heart disease using TLD dosimetry and Monte Carlo simulation

    International Nuclear Information System (INIS)

    Yakoumakis, E N; Gialousis, G I; Papadopoulou, Despina; Makri, Triantafillia; Pappouli, Zografia; Yakoumakis, Nikolaos; Papagiannis, Panayotis; Georgiou, Evangelos

    2009-01-01

    Entrance surface radiation doses were measured with thermoluminescent dosimeters for 98 children who were referred to a cardiology department for the diagnosis or the treatment of a congenital heart disease. Additionally, all the radiographic parameters were recorded and Monte Carlo simulations were performed for the estimation of entrance surface dose to effective dose conversion factors, in order to further calculate the effective dose for each child. For diagnostic catheterisations the values ranged from 0.16 to 14.44 mSv, with average 3.71 mSv, and for therapeutic catheterisations the values ranged from 0.38 to 25.01 mSv, with average value 5 mSv. Effective doses were estimated for diagnostic procedures and interventional procedures performed for the treatment of five different heart diseases: (a) atrial septal defect (ASD), (b) ventricular septal defect (VSD), (c) patent ductus arteriosus (PDA), (d) aorta coarctation and (e) pulmonary stenosis. The high levels of radiation exposure are, however, balanced with the advantages of cardiac catheterisations such as the avoidance of surgical closure and the necessity of shorter or even no hospitalisation.

  14. Estimation of children's radiation dose from cardiac catheterisations, performed for the diagnosis or the treatment of a congenital heart disease using TLD dosimetry and Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Yakoumakis, E N; Gialousis, G I; Papadopoulou, Despina; Makri, Triantafillia; Pappouli, Zografia; Yakoumakis, Nikolaos; Papagiannis, Panayotis; Georgiou, Evangelos [Medical Physics Department, University of Athens, 75 Mikras Asias Street, Athens 11527 (Greece)

    2009-06-15

    Entrance surface radiation doses were measured with thermoluminescent dosimeters for 98 children who were referred to a cardiology department for the diagnosis or the treatment of a congenital heart disease. Additionally, all the radiographic parameters were recorded and Monte Carlo simulations were performed for the estimation of entrance surface dose to effective dose conversion factors, in order to further calculate the effective dose for each child. For diagnostic catheterisations the values ranged from 0.16 to 14.44 mSv, with average 3.71 mSv, and for therapeutic catheterisations the values ranged from 0.38 to 25.01 mSv, with average value 5 mSv. Effective doses were estimated for diagnostic procedures and interventional procedures performed for the treatment of five different heart diseases: (a) atrial septal defect (ASD), (b) ventricular septal defect (VSD), (c) patent ductus arteriosus (PDA), (d) aorta coarctation and (e) pulmonary stenosis. The high levels of radiation exposure are, however, balanced with the advantages of cardiac catheterisations such as the avoidance of surgical closure and the necessity of shorter or even no hospitalisation.

  15. Exposure Estimation and Interpretation of Occupational Risk: Enhanced Information for the Occupational Risk Manager

    Science.gov (United States)

    Waters, Martha; McKernan, Lauralynn; Maier, Andrew; Jayjock, Michael; Schaeffer, Val; Brosseau, Lisa

    2015-01-01

    The fundamental goal of this article is to describe, define, and analyze the components of the risk characterization process for occupational exposures. Current methods are described for the probabilistic characterization of exposure, including newer techniques that have increasing applications for assessing data from occupational exposure scenarios. In addition, since the probability of health effects reflects variability in the exposure estimate as well as the dose-response curve—the integrated considerations of variability surrounding both components of the risk characterization provide greater information to the occupational hygienist. Probabilistic tools provide a more informed view of exposure as compared to use of discrete point estimates for these inputs to the risk characterization process. Active use of such tools for exposure and risk assessment will lead to a scientifically supported worker health protection program. Understanding the bases for an occupational risk assessment, focusing on important sources of variability and uncertainty enables characterizing occupational risk in terms of a probability, rather than a binary decision of acceptable risk or unacceptable risk. A critical review of existing methods highlights several conclusions: (1) exposure estimates and the dose-response are impacted by both variability and uncertainty and a well-developed risk characterization reflects and communicates this consideration; (2) occupational risk is probabilistic in nature and most accurately considered as a distribution, not a point estimate; and (3) occupational hygienists have a variety of tools available to incorporate concepts of risk characterization into occupational health and practice. PMID:26302336

  16. Second Report. Dose reduction of occupational exposure during cardiac catheterization and angiography

    International Nuclear Information System (INIS)

    Saito, Yoshimi; Matsumoto, Kunihiro; Fujihashi, Hiroshi; Umeda, Kazuhiro

    2000-01-01

    Since X-ray fluoroscopy in the IVR has tended to take longer than usual diagnosis, exposure of medical personnel to scattered X-rays has increased and become a problem. The authors report the results of a questionnaire survey to investigate the types of devices currently being used in medical facilities to protect against scattered X-ray exposure. Questionnaires were distributed to a total of 71 medical facilities, and replies were obtained from 57 (80%). Many facilities used ''ceiling-suspended types'', as commercially available devices, and ''examining-table fixed type'' and ''mobile type'' devices were described as self-manufactured devices in some facilities. The overall evaluation of protective devices yielded opinions such as ''time-consuming'', ''restricted imaging directions'' and expensive'', and the mobile-type devices were said to involve the problem of taking up a great deal of space in the fluoroscopy room. In regard to the problems or degree of satisfaction with the devices, 75% answered ''we have some problems'', but a reply of ''unsatisfactory'' was obtained from only one facility. The results of this survey show that popularization of protective devices and reduction of exposure depend on ''consideration of operator exposure'' and that it is important to increase awareness of exposure and the need for protective devices. (K.H.)

  17. Early transcriptional changes in cardiac mitochondria during chronic doxorubicin exposure and mitigation by dexrazoxane in mice

    Energy Technology Data Exchange (ETDEWEB)

    Vijay, Vikrant; Moland, Carrie L.; Han, Tao; Fuscoe, James C. [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Lee, Taewon [Department of Mathematics, Korea University, Sejong (Korea, Republic of); Herman, Eugene H. [Toxicology and Pharmacology Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, The National Cancer Institute, 9609 Medical Center Drive, Rockville, MD 20850-9734 (United States); Jenkins, G. Ronald [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Lewis, Sherry M. [Office of Scientific Coordination, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Cummings, Connie A. [UltraPath Imaging, 2228 Page Road, Durham, NC 27703 (United States); Gao, Yuan; Cao, Zhijun; Yu, Li-Rong [Biomarkers and Alternative Models Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Desai, Varsha G., E-mail: varsha.desai@fda.hhs.gov [Personalized Medicine Branch, Division of Systems Biology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States)

    2016-03-15

    Identification of early biomarkers of cardiotoxicity could help initiate means to ameliorate the cardiotoxic actions of clinically useful drugs such as doxorubicin (DOX). Since DOX has been shown to target mitochondria, transcriptional levels of mitochondria-related genes were evaluated to identify early candidate biomarkers in hearts of male B6C3F{sub 1} mice given a weekly intravenous dose of 3 mg/kg DOX or saline (SAL) for 2, 3, 4, 6, or 8 weeks (6, 9, 12, 18, or 24 mg/kg cumulative DOX doses, respectively). Also, a group of mice was pretreated (intraperitoneally) with the cardio-protectant, dexrazoxane (DXZ; 60 mg/kg) 30 min before each weekly dose of DOX or SAL. At necropsy a week after the last dose, increased plasma concentrations of cardiac troponin T (cTnT) were detected at 18 and 24 mg/kg cumulative DOX doses, whereas myocardial alterations were observed only at the 24 mg/kg dose. Of 1019 genes interrogated, 185, 109, 140, 184, and 451 genes were differentially expressed at 6, 9, 12, 18, and 24 mg/kg cumulative DOX doses, respectively, compared to concurrent SAL-treated controls. Of these, expression of 61 genes associated with energy metabolism and apoptosis was significantly altered before and after occurrence of myocardial injury, suggesting these as early genomics markers of cardiotoxicity. Much of these DOX-induced transcriptional changes were attenuated by pretreatment of mice with DXZ. Also, DXZ treatment significantly reduced plasma cTnT concentration and completely ameliorated cardiac alterations induced by 24 mg/kg cumulative DOX. This information on early transcriptional changes during DOX treatment may be useful in designing cardioprotective strategies targeting mitochondria. - Highlights: • Altered mitochondria-related gene expression before heart injury by doxorubicin • Dexrazoxane mitigated doxorubicin-induced early expression changes in mitochondria. • Dexrazoxane completely ameliorated doxorubicin-induced pathology in mouse heart.

  18. Estimating group size: effects of category membership, differential construal and selective exposure

    NARCIS (Netherlands)

    Bosveld, W.; Koomen, W.; van der Pligt, J.

    1996-01-01

    Examined the role of category membership, differential construal, and selective exposure in consensus estimation concerning the social categorization of religion. 54 involved and less involved Christians and 40 non-believers were asked to estimate the percentage of Christians in the Netherlands

  19. Novel serologic biomarkers provide accurate estimates of recent Plasmodium falciparum exposure for individuals and communities.

    Science.gov (United States)

    Helb, Danica A; Tetteh, Kevin K A; Felgner, Philip L; Skinner, Jeff; Hubbard, Alan; Arinaitwe, Emmanuel; Mayanja-Kizza, Harriet; Ssewanyana, Isaac; Kamya, Moses R; Beeson, James G; Tappero, Jordan; Smith, David L; Crompton, Peter D; Rosenthal, Philip J; Dorsey, Grant; Drakeley, Christopher J; Greenhouse, Bryan

    2015-08-11

    Tools to reliably measure Plasmodium falciparum (Pf) exposure in individuals and communities are needed to guide and evaluate malaria control interventions. Serologic assays can potentially produce precise exposure estimates at low cost; however, current approaches based on responses to a few characterized antigens are not designed to estimate exposure in individuals. Pf-specific antibody responses differ by antigen, suggesting that selection of antigens with defined kinetic profiles will improve estimates of Pf exposure. To identify novel serologic biomarkers of malaria exposure, we evaluated responses to 856 Pf antigens by protein microarray in 186 Ugandan children, for whom detailed Pf exposure data were available. Using data-adaptive statistical methods, we identified combinations of antibody responses that maximized information on an individual's recent exposure. Responses to three novel Pf antigens accurately classified whether an individual had been infected within the last 30, 90, or 365 d (cross-validated area under the curve = 0.86-0.93), whereas responses to six antigens accurately estimated an individual's malaria incidence in the prior year. Cross-validated incidence predictions for individuals in different communities provided accurate stratification of exposure between populations and suggest that precise estimates of community exposure can be obtained from sampling a small subset of that community. In addition, serologic incidence predictions from cross-sectional samples characterized heterogeneity within a community similarly to 1 y of continuous passive surveillance. Development of simple ELISA-based assays derived from the successful selection strategy outlined here offers the potential to generate rich epidemiologic surveillance data that will be widely accessible to malaria control programs.

  20. Measurement error in mobile source air pollution exposure estimates due to residential mobility during pregnancy.

    Science.gov (United States)

    Pennington, Audrey Flak; Strickland, Matthew J; Klein, Mitchel; Zhai, Xinxin; Russell, Armistead G; Hansen, Craig; Darrow, Lyndsey A

    2017-09-01

    Prenatal air pollution exposure is frequently estimated using maternal residential location at the time of delivery as a proxy for residence during pregnancy. We describe residential mobility during pregnancy among 19,951 children from the Kaiser Air Pollution and Pediatric Asthma Study, quantify measurement error in spatially resolved estimates of prenatal exposure to mobile source fine particulate matter (PM 2.5 ) due to ignoring this mobility, and simulate the impact of this error on estimates of epidemiologic associations. Two exposure estimates were compared, one calculated using complete residential histories during pregnancy (weighted average based on time spent at each address) and the second calculated using only residence at birth. Estimates were computed using annual averages of primary PM 2.5 from traffic emissions modeled using a Research LINE-source dispersion model for near-surface releases (RLINE) at 250 m resolution. In this cohort, 18.6% of children were born to mothers who moved at least once during pregnancy. Mobile source PM 2.5 exposure estimates calculated using complete residential histories during pregnancy and only residence at birth were highly correlated (r S >0.9). Simulations indicated that ignoring residential mobility resulted in modest bias of epidemiologic associations toward the null, but varied by maternal characteristics and prenatal exposure windows of interest (ranging from -2% to -10% bias).

  1. Uncertain quantities in estimating radiation exposure from former landfill sites: groundwater pathway

    International Nuclear Information System (INIS)

    Kistinger, S.

    2005-01-01

    With regard to the title of the closed meeting, ''Realistic determination of radiation exposure'', we state that generic estimates can by definition never be realistic, but that it is their purpose to be conservative. However this still leaves us with the question of how conservative a generic dose estimate must be and how the existing variability or indeterminacy of reality should be taken into account. This paper presents various methods for dealing with this indeterminacy in generic dose estimates. The example used for this purpose is a simplified model for the determination of the potential radiation exposure caused by a former landfill site via the water pathway

  2. Estimation of exposure to 222Rn from the excretion rates of 21πPb

    International Nuclear Information System (INIS)

    Holtzman, R.B.; Rundo, J.

    1981-01-01

    A model is proposed with which estimates of exposure to 227 Rn and its daughter products may be made from urinary excretion rates of 210 Pb. It is assumed that 20% of all the 210 Pb inhaled reaches the blood and that 50% of the endogenous excretion is through the urine. The estimates from the model are compared with the results of measurements on a subject residing in a house with high levels of radon. Whole body radioactivity and excretion data were consistent with the model, but the estimates of exposure (WL) were higher than those measured with an Environmental Working Level Monitor

  3. Cytogenetic examination of cosmonauts for space radiation exposure estimation

    Science.gov (United States)

    Snigiryova, G. P.; Novitskaya, N. N.; Fedorenko, B. S.

    2012-08-01

    PurposeTo evaluate radiation induced chromosome aberration frequency in peripheral blood lymphocytes of cosmonauts who participated in flights on Mir Orbital Station and ISS (International Space Station). Materials and methodsCytogenetic examination which has been performed in the period 1992-2008 included the analysis of chromosome aberrations using conventional Giemsa staining method in 202 blood samples from 48 cosmonauts who participated in flights on Mir Orbital Station and ISS. ResultsSpace flights led to an increase of chromosome aberration frequency. Frequency of dicentrics plus centric rings (Dic+Rc) depend on the space flight duration and accumulated dose value. After the change of space stations (from Mir Orbital Station to ISS) the radiation load of cosmonauts based on data of cytogenetic examination decreased. Extravehicular activity also adds to chromosome aberration frequency in cosmonauts' blood lymphocytes. Average doses after the first flight, estimated by the frequency of Dic+Rc, were 227 and 113 mGy Eq for long-term flights (LTF) and 107 and 53 mGy Eq for short-term flights (STF). ConclusionCytogenetic examination of cosmonauts can be applied to assess equivalent doses.

  4. Precise Estimation of Cellular Radio Electromagnetic Field in Elevators and EMI Impact on Implantable Cardiac Pacemakers

    Science.gov (United States)

    Harris, Louis-Ray; Hikage, Takashi; Nojima, Toshio

    The purpose of this paper is to investigate the possible impact of cellular phones' signals on implantable cardiac pacemakers in elevators. This is achieved by carrying out precise numerical simulations based on the Finite-Difference-Time-Domain method to examine the electromagnetic fields in elevator models. In order to examine the realistic and complicated situations where humans are present in the elevator, we apply the realistic homogeneous human phantom and cellular radios operating in the frequency bands 800MHz, 1.5GHz and 2GHz. These computed results of field strength inside the elevator are compared with a certain reference level determined from the experimentally obtained maximum interference distance of implantable cardiac pacemakers. This enables us to carry out a quantitative evaluation of the EMI risk to pacemakers by cellular radio transmission. The results show that for the case when up to 5 mobile radio users are present in the elevator model used, there is no likelihood of pacemaker malfunction for the frequency bands 800MHz, 1.5GHz and 2GHz.

  5. Silica exposure and silicosis among Ontario hardrock miners: II. Exposure estimates.

    Science.gov (United States)

    Verma, D K; Sebestyen, A; Julian, J A; Muir, D C; Schmidt, H; Bernholz, C D; Shannon, H S

    1989-01-01

    An epidemiological investigation was carried out to determine the relationship between silicosis in hardrock miners in Ontario and cumulative exposure to silica (free crystalline silica--alpha quartz) dust. This second report describes a side-by-side air-sampling program used to derive a konimeter/gravimetric silica conversion curve. A total of 2,360 filter samples and 90,000 konimeter samples were taken over 2 years in two mines representing the ore types gold and uranium, both in existing conditions as well as in an experimental stope in which dry drilling was used to simulate the high dust conditions of the past. The method of calculating cumulative respirable silica exposure indices for each miner is reported.

  6. Magnetic Field Exposure Estimates Based on Power Lines Near Homes (invited paper)

    International Nuclear Information System (INIS)

    Ahlbom, A.; Feychting, M.

    1999-01-01

    Several epidemiological studies have based their estimates of magnetic field exposure on the proximity to power lines. This has been done in three principally different ways, which differ in the amount of information that is used. These are: (1) distance; (2) distance and configuration (wire code); and (3) distance, configuration, and load (calculated field). It is presumed that the more information that is used, the more accurate is the exposure estimate. All these three approaches suffer from the limitation that they only account for exposure that is generated by power lines. The influence on the in-home magnetic field from sources other than the power line are not considered, nor is exposure experienced at places other than the home. This raises the following question. What is the implication for the result of the epidemiological study of the exposure misclassification that is introduced by basing magnetic field exposure estimation on power lines near homes? Although the necessary information is only partly at hand the answers to this question will be discussed. The basis will be some general epidemiological principles combined with data from a Swedish study on residential exposure and cancer risk. (author)

  7. Towards estimating the burden of disease attributable to second-hand smoke exposure in Polish children

    Directory of Open Access Journals (Sweden)

    Dorota Jarosińska

    2014-02-01

    Full Text Available Objectives: To estimate the burden of disease attributable to second-hand smoke (SHS exposure in Polish children in terms of the number of deaths and disability adjusted life years (DALYs due to lower respiratory infections (LRI, otitis media (OM, asthma, low birth weight (LBW and sudden infant death syndrome (SIDS. Materials and Methods: Estimates of SHS exposure in children and in pregnant women as well as information concerning maternal smoking were derived from a national survey, the Global Youth Tobacco Survey, and the Global Adult Tobacco Survey in Poland. Mortality data (LRI, OM, asthma, and SIDS, the number of cases (LBW, and population data were obtained from national statistics (year 2010, and DALYs came from the WHO (year 2004. The burden of disease due to SHS was calculated by multiplying the total burden of a specific health outcome (deaths or DALYs by a population attributable fraction. Results: Using two estimates of SHS exposure in children: 48% and 60%, at least 12 and 14 deaths from LRI in children aged up to 2 years were attributed to SHS, for the two exposure scenarios, respectively. The highest burden of DALYs was for asthma in children aged up to 15 years: 2412, and 2970 DALYs, for the two exposure scenarios, respectively. For LRI, 419 and 500 DALYs, and for OM, 61 and 77 DALYs were attributed to SHS, for the two exposure scenarios, respectively. Between 13% and 27% of SIDS cases and between 3% and 16% of the cases of LBW at term were attributed to SHS exposure. Conclusions: This study provides a conservative estimate of the public health impact of SHS exposure on Polish children. Lack of comprehensive, up to date health data concerning children, as well as lack of measures that would best reflect actual SHS exposure are major limitations of the study, likely to underestimate the burden of disease.

  8. Out-of-Hospital Cardiac Arrests and Outdoor Air Pollution Exposure in Copenhagen, Denmark

    DEFF Research Database (Denmark)

    Wichmann, Janine; Folke, Fredrik; Torp-Pedersen, Christian

    2013-01-01

    -of-hospital cardiac arrests (OHCA) and hourly and daily outdoor levels of PM(10), PM(2.5), coarse fraction of PM (PM(10-2.5)), ultrafine particle proxies, NO(x), NO(2), O(3) and CO in Copenhagen, Denmark, for the period 2000-2010. Susceptible groups by age and sex was also investigated. A case-crossover design...... was applied. None of the hourly lags of any of the pollutants were significantly associated with OHCA events. The strongest association with OHCA events was observed for the daily lag4 of PM(2.5), lag3 of PM(10), lag3 of PM(10-2.5), lag3 of NO(x) and lag4 of CO. An IQR increase of PM(2.5) and PM(10......) was associated with a significant increase of 4% (95% CI: 0%; 9%) and 5% (95% CI: 1%; 9%) in OHCA events with 3 days lag, respectively. None of the other daily lags or other pollutants was significantly associated with OHCA events. Adjustment for O(3) slightly increased the association between OHCA and PM(2...

  9. Coefficients calculations of conversion of cancer risk for occupational exposure using Monte Carlo simulations in cardiac procedures of interventionist radiology

    International Nuclear Information System (INIS)

    Santos, William S.; Neves, Lucio P.; Perini, Ana P.; Caldas, Linda V.E.; Maia, Ana F.

    2014-01-01

    Cardiac procedures are among the most common procedures in interventional radiology (IR), and can lead to high medical and occupational exposures, as in most cases are procedures complex and long lasting. In this work, conversion coefficients (CC) for the risk of cancer, normalized by kerma area product (KAP) to the patient, cardiologist and nurse were calculated using Monte Carlo simulation. The patient and the cardiologist were represented by anthropomorphic simulators MESH, and the nurse by anthropomorphic phantom FASH. Simulators were incorporated into the code of Monte Carlo MCNPX. Two scenarios were created: in the first (1), lead curtain and protective equipment suspended were not included, and in the second (2) these devices were inserted. The radiographic parameters employed in Monte Carlo simulations were: tube voltage of 60 kVp and 120 kVp; filtration of the beam and 3,5 mmAl beam area of 10 x 10 cm 2 . The average values of CCs to eight projections (in 10 -4 / Gy.cm 2 were 1,2 for the patient, 2,6E-03 (scenario 1) and 4,9E-04 (scenario 2) for cardiologist and 5,2E-04 (scenario 1) and 4,0E-04 (Scenario 2) to the nurse. The results show a significant reduction in CCs for professionals, when the lead curtain and protective equipment suspended are employed. The evaluation method used in this work can provide important information on the risk of cancer patient and professional, and thus improve the protection of workers in cardiac procedures of RI

  10. Estimating post-marketing exposure to pharmaceutical products using ex-factory distribution data.

    Science.gov (United States)

    Telfair, Tamara; Mohan, Aparna K; Shahani, Shalini; Klincewicz, Stephen; Atsma, Willem Jan; Thomas, Adrian; Fife, Daniel

    2006-10-01

    The pharmaceutical industry has an obligation to identify adverse reactions to drug products during all phases of drug development, including the post-marketing period. Estimates of population exposure to pharmaceutical products are important to the post-marketing surveillance of drugs, and provide a context for assessing the various risks and benefits, including drug safety, associated with drug treatment. This paper describes a systematic approach to estimating post-marketing drug exposure using ex-factory shipment data to estimate the quantity of medication available, and dosage information (stratified by indication or other factors as appropriate) to convert the quantity of medication to person time of exposure. Unlike the non-standardized methods often used to estimate exposure, this approach provides estimates whose calculations are explicit, documented, and consistent across products and over time. The methods can readily be carried out by an individual or small group specializing in this function, and lend themselves to automation. The present estimation approach is practical and relatively uncomplicated to implement. We believe it is a useful innovation. Copyright 2006 John Wiley & Sons, Ltd.

  11. Canines as sentinel species for assessing chronic exposures to air pollutants: part 2. Cardiac pathology.

    Science.gov (United States)

    Calderón-Garcidueñas, L; Gambling, T M; Acuña, H; García, R; Osnaya, N; Monroy, S; Villarreal-Calderón, A; Carson, J; Koren, H S; Devlin, R B

    2001-06-01

    The principal objective of this study is to evaluate by light and electron microscopy (LM, EM) the heart tissues in stray southwest and northeast metropolitan Mexico City (SWMMC, NEMMC) dogs and compare their findings to those from 3 less polluted cities (Cuernavaca, Tlaxcala, and Tuxpam). Clinically healthy mongrel dogs, including 109 from highly polluted SWMMC and NEMMC, and 43 dogs from less polluted cities were studied. Dogs residing in cities with lower levels of pollutants showed little or no cardiac abnormalities. Mexico City and Cuernavaca dogs exhibited LM myocardial alterations including apoptotic myocytes, endothelial and immune effector cells, degranulated mast cells associated with scattered foci of mononuclear cells in left and right ventricles and interventricular septum, and clusters of adipocytes interspersed with mononuclear cells. Vascular changes included scattered polymorphonuclear leukocytes (PMN) margination and microthrombi in capillaries, and small venous and arteriolar blood vessels. Small veins exhibited smooth muscle cell hyperplasia, and arteriolar blood vessels showed deposition of particulate matter (PM) in the media and adventitia. Unmyelinated nerve fibers showed endoneural and epineural degranulated mast cells. EM examination of myocardial mast cells showed distended and abundant rough endoplasmic reticulum with few secretory granules. Myocardial capillaries exhibited fibrin deposition and their endothelial cells displayed increased luminal and abluminal pinocytic activity and the formation of anemone-like protrusions of the endothelium into the lumen. A close association between myocardial findings, lung epithelial and endothelial pathology, and chronic inflammatory lung changes was noted. The myocardial changes described in dogs exposed to ambient air pollutants may form the basis for developing hypothesis-driven mechanistic studies that might explain the epidemiological data of increased cardiovascular morbidity and mortality in

  12. Estimating the whole-body exposure annual dose of radiation workers of petroleum nuclear well logging

    International Nuclear Information System (INIS)

    Tian Yizong; Gao Jianzheng; Liu Wenhong

    2006-01-01

    Objective: By imitating experiment of radioactive sources being installed, to estimate the annual whole-body exposure dose of radiation workers of petroleum nuclear determining wells; Methods: To compre the values of the theory, imitating experiment and γ individual dose monitor calculations. Results: The three values measured above tally with one anather. Conclusion: The annual whole-body exposure doses of radiation workers of petroleum nuclear determining wells are no more than 5 mSv. (authors)

  13. ART, Stoffenmanager, and TRA: A Systematic Comparison of Exposure Estimates Using the TREXMO Translation System.

    Science.gov (United States)

    Savic, Nenad; Gasic, Bojan; Vernez, David

    2017-12-15

    Several occupational exposure models are recommended under the EU's REACH legislation. Due to limited availability of high-quality exposure data, their validation is an ongoing process. It was shown, however, that different models may calculate significantly different estimates and thus lead to potentially dangerous conclusions about chemical risk. In this paper, the between-model translation rules defined in TREXMO were used to generate 319000 different in silico exposure situations in ART, Stoffenmanager, and ECETOC TRA v3. The three models' estimates were computed and the correlation and consistency between them were investigated. The best correlated pair was Stoffenmanager-ART (R, 0.52-0.90), whereas the ART-TRA and Stoffenmanager-TRA correlations were either lower (R, 0.36-0.69) or no correlation was found. Consistency varied significantly according to different exposure types (e.g. vapour versus dust) or settings (near-field versus far-field and indoors versus outdoors). The percentages of generated situations for which estimates differed by more than a factor of 100 ranged from 14 to 97%, 37 to 99%, and 1 to 68% for Stoffenmanager-ART, TRA-ART, and TRA-Stoffenmanager, respectively. Overall, the models were more consistent for vapours than for dusts and solids, near-fields than for far-fields, and indoor than for outdoor exposure. Multiple linear regression analyses evidenced the relationship between the models' parameters and the relative differences between the models' predictions. The relative difference can be used to estimate the consistency between the models. Furthermore, the study showed that the tiered approach is not generally applicable to all exposure situations. These findings emphasize the need for a multiple-model approach to assessing critical exposure scenarios under REACH. Moreover, in combination with occupational exposure measurements, they might also be used for future studies to improve prediction accuracy. © The Author(s) 2017

  14. Association Between Satellite-based Estimates of Long-term PM2.5 Exposure and Coronary Artery Disease

    Science.gov (United States)

    Background: Epidemiological studies have identified associations between long-term PM2.5 exposure and cardiovascular events, though most have relied on concentrations from central-site air quality monitors. Methods: We utilized a cohort of 5679 patients who had undergone cardiac ...

  15. Some statistical considerations related to the estimation of cancer risk following exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Land, C.E.; Pierce, D.A.

    1983-01-01

    Statistical theory and methodology provide the logical structure for scientific inference about the cancer risk associated with exposure to ionizing radiation. Although much is known about radiation carcinogenesis, the risk associated with low-level exposures is difficult to assess because it is too small to measure directly. Estimation must therefore depend upon mathematical models which relate observed risks at high exposure levels to risks at lower exposure levels. Extrapolated risk estimates obtained using such models are heavily dependent upon assumptions about the shape of the dose-response relationship, the temporal distribution of risk following exposure, and variation of risk according to variables such as age at exposure, sex, and underlying population cancer rates. Expanded statistical models, which make explicit certain assumed relationships between different data sets, can be used to strengthen inferences by incorporating relevant information from diverse sources. They also allow the uncertainties inherent in information from related data sets to be expressed in estimates which partially depend upon that information. To the extent that informed opinion is based upon a valid assessment of scientific data, the larger context of decision theory, which includes statistical theory, provides a logical framework for the incorporation into public policy decisions of the informational content of expert opinion

  16. The impact of composite AUC estimates on the prediction of systemic exposure in toxicology experiments.

    Science.gov (United States)

    Sahota, Tarjinder; Danhof, Meindert; Della Pasqua, Oscar

    2015-06-01

    Current toxicity protocols relate measures of systemic exposure (i.e. AUC, Cmax) as obtained by non-compartmental analysis to observed toxicity. A complicating factor in this practice is the potential bias in the estimates defining safe drug exposure. Moreover, it prevents the assessment of variability. The objective of the current investigation was therefore (a) to demonstrate the feasibility of applying nonlinear mixed effects modelling for the evaluation of toxicokinetics and (b) to assess the bias and accuracy in summary measures of systemic exposure for each method. Here, simulation scenarios were evaluated, which mimic toxicology protocols in rodents. To ensure differences in pharmacokinetic properties are accounted for, hypothetical drugs with varying disposition properties were considered. Data analysis was performed using non-compartmental methods and nonlinear mixed effects modelling. Exposure levels were expressed as area under the concentration versus time curve (AUC), peak concentrations (Cmax) and time above a predefined threshold (TAT). Results were then compared with the reference values to assess the bias and precision of parameter estimates. Higher accuracy and precision were observed for model-based estimates (i.e. AUC, Cmax and TAT), irrespective of group or treatment duration, as compared with non-compartmental analysis. Despite the focus of guidelines on establishing safety thresholds for the evaluation of new molecules in humans, current methods neglect uncertainty, lack of precision and bias in parameter estimates. The use of nonlinear mixed effects modelling for the analysis of toxicokinetics provides insight into variability and should be considered for predicting safe exposure in humans.

  17. Model-based estimation with boundary side information or boundary regularization [cardiac emission CT].

    Science.gov (United States)

    Chiao, P C; Rogers, W L; Fessler, J A; Clinthorne, N H; Hero, A O

    1994-01-01

    The authors have previously developed a model-based strategy for joint estimation of myocardial perfusion and boundaries using ECT (emission computed tomography). They have also reported difficulties with boundary estimation in low contrast and low count rate situations. Here they propose using boundary side information (obtainable from high resolution MRI and CT images) or boundary regularization to improve both perfusion and boundary estimation in these situations. To fuse boundary side information into the emission measurements, the authors formulate a joint log-likelihood function to include auxiliary boundary measurements as well as ECT projection measurements. In addition, they introduce registration parameters to align auxiliary boundary measurements with ECT measurements and jointly estimate these parameters with other parameters of interest from the composite measurements. In simulated PET O-15 water myocardial perfusion studies using a simplified model, the authors show that the joint estimation improves perfusion estimation performance and gives boundary alignment accuracy of <0.5 mm even at 0.2 million counts. They implement boundary regularization through formulating a penalized log-likelihood function. They also demonstrate in simulations that simultaneous regularization of the epicardial boundary and myocardial thickness gives comparable perfusion estimation accuracy with the use of boundary side information.

  18. Black-box modeling to estimate tissue temperature during radiofrequency catheter cardiac ablation: feasibility study on an agar phantom model

    International Nuclear Information System (INIS)

    Blasco-Gimenez, Ramón; Lequerica, Juan L; Herrero, Maria; Hornero, Fernando; Berjano, Enrique J

    2010-01-01

    The aim of this work was to study linear deterministic models to predict tissue temperature during radiofrequency cardiac ablation (RFCA) by measuring magnitudes such as electrode temperature, power and impedance between active and dispersive electrodes. The concept involves autoregressive models with exogenous input (ARX), which is a particular case of the autoregressive moving average model with exogenous input (ARMAX). The values of the mode parameters were determined from a least-squares fit of experimental data. The data were obtained from radiofrequency ablations conducted on agar models with different contact pressure conditions between electrode and agar (0 and 20 g) and different flow rates around the electrode (1, 1.5 and 2 L min −1 ). Half of all the ablations were chosen randomly to be used for identification (i.e. determination of model parameters) and the other half were used for model validation. The results suggest that (1) a linear model can be developed to predict tissue temperature at a depth of 4.5 mm during RF cardiac ablation by using the variables applied power, impedance and electrode temperature; (2) the best model provides a reasonably accurate estimate of tissue temperature with a 60% probability of achieving average errors better than 5 °C; (3) substantial errors (larger than 15 °C) were found only in 6.6% of cases and were associated with abnormal experiments (e.g. those involving the displacement of the ablation electrode) and (4) the impact of measuring impedance on the overall estimate is negligible (around 1 °C)

  19. Consumer exposure. Basic considerations for regulatory exposure estimations; Exposition des Verbrauchers. Grundlegende Ueberlegungen fuer die Expositionsabschaetzung im regulatorischen Bereich

    Energy Technology Data Exchange (ETDEWEB)

    Heinemeyer, G. [Bundesinstitut fuer Risikobewertung, Berlin (Germany)

    2003-05-01

    ) or LOAEL (low observed adverse effect level). A small hazard/exposure ratio can be attributed to a probability of high risk, whereas a large ratio indicates a small risk of health hazards. The following article discusses the main principles of exposure estimation. (orig.) [German] Die Bewertung von Verbraucherexpositionen umschliesst alle Quellen und Pfade, ueber die Personen im privaten und haeuslichen Umfeld mit Chemikalien in Kontakt kommen. Dabei sind Verbraucher nicht nur diejenigen, die selbst Verbraucherprodukte anwenden, sondern auch alle weiteren Personen, die sekundaer (indirekt) mit dem Produkt Kontakt haben, z.B. Familienangehoerige. Eine Verbraucherexposition kann gemessen oder geschaetzt werden. Beide Verfahren haben Vor- und Nachteile. Waehrend sich Messungen meistens auf individuelle Expositionssituationen beziehen, beschreiben Modelle eher eine verallgemeinerte Expositionssituation (Szenario). Messungen haben daher ihren Platz, wo Quellen von Schadstoffen aufgespuert werden muessen, Modelle eher dort, wo systematisierte Betrachtungen von Risiken durchgefuehrt werden. Zur Expositionsschaetzung gehoeren 3 Abschnitte, erstens die Charakterisierung der Expositionsquelle (z.B. eine Haushaltschemikalie) mit Beschreibung der Anwendungsmodalitaeten (Haeufigkeit, Dauer); zweitens die Beschreibung des zeitlichen Verlaufes der Konzentration des Stoffes im Kontaktmedium, vor allem in der Luft und auf der Haut. Die Exposition wird darueber hinaus durch das Verhalten der exponierten Person selbst bestimmt. Hier ist die Kontaktdauer, auch Zeitbudget genannt, von grosser Bedeutung. Besondere Verhaltensmuster koennen auch fuer bestimmte Populationen von Bedeutung sein. Man nimmt an, dass z.B. im Kindesalter die orale Aufnahme durch das sog. Mouthing (Hand-in-den-Mund-Stecken) eine besondere Rolle spielt. Die Risikocharakterisierung erfolgt durch einen Vergleich der Exposition, ausgedrueckt als Konzentration oder Dosis, mit dem NOAEL (No Observed Adverse Effect Level

  20. Trait anxiety mediates the effect of stress exposure on post-traumatic stress disorder and depression risk in cardiac surgery patients.

    Science.gov (United States)

    Kok, Lotte; Sep, Milou S; Veldhuijzen, Dieuwke S; Cornelisse, Sandra; Nierich, Arno P; van der Maaten, Joost; Rosseel, Peter M; Hofland, Jan; Dieleman, Jan M; Vinkers, Christiaan H; Joëls, Marian; van Dijk, Diederik; Hillegers, Manon H

    2016-12-01

    Post-traumatic stress disorder (PTSD) and depression are common after cardiac surgery. Lifetime stress exposure and personality traits may influence the development of these psychiatric conditions. Self-reported rates of PTSD and depression and potential determinants (i.e., trait anxiety and stress exposure) were established 1.5 to 4 years after cardiac surgery. Data was available for 1125 out of 1244 (90.4%) participants. Multivariable linear regressions were conducted to investigate mediating and/or moderating effects of trait anxiety on the relationship between stress exposure, and PTSD and depression. Pre-planned subgroup analyses were performed for both sexes. PTSD and depression symptoms were present in 10.2% and 13.1% of the participants, respectively. Trait anxiety was a full mediator of the association between stress exposure and depression in both the total cohort and female and male subgroups. Moreover, trait anxiety partially mediated the relationship between stress exposure and PTSD in the full cohort and the male subgroup, whereas trait anxiety fully mediated this relationship in female patients. Trait anxiety did not play a moderating role in the total patient sample, nor after stratification on gender. The unequal distribution of male (78%) and female patients (22%) might limit the generalizability of our findings. Furthermore, risk factors were investigated retrospectively and with variable follow-up time. In cardiac surgery patients, trait anxiety was found to be an important mediator of postoperative PTSD and depression. Prospective research is necessary to verify whether these factors are reliable screening measures of individuals' vulnerability for psychopathology development after cardiac surgery. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. The non-invasive and continuous estimation of cardiac output using a photoplethysmogram and electrocardiogram during incremental exercise

    International Nuclear Information System (INIS)

    Wang, L; Poon, C C Y; Zhang, Y T

    2010-01-01

    Cardiac output (CO) monitoring is not only essential for critically ill patients in the hospital, but also for patients at home and those undergoing cardiopulmonary exercise testing. However, CO is difficult to monitor during daily activities and exercise. In this paper, we aim at developing a novel CO estimation method that can be used under these challenging conditions. The tube model was utilized to derive a CO index, namely the pulse time reflection ratio (PTRR) from an electrocardiogram and photoplethysmogram. After calibration, the PTRR can be used to estimate beat-to-beat CO. The proposed method was verified against CO measured by impedance cardiography on 19 healthy subjects in an incremental intensity exercise test. Results showed that there were strong correlations (r) between the PTRR and reference CO in 18 subjects (mean r: 0.88, n = 245 trials). Two calibration approaches reported in the literature were applied to the proposed method and the corresponding bias ± precisions of estimation errors were 0 ± 1.89 L min −1 and −0.22 ± 2.12 L min −1 , respectively. The percent errors were 21.94% and 24.90%, smaller than the clinical acceptance limit (30%). To conclude, after calibration, this method can be used to monitor CO on healthy subjects during incremental intensity exercise

  2. Estimate of safe human exposure levels for lunar dust based on comparative benchmark dose modeling.

    Science.gov (United States)

    James, John T; Lam, Chiu-Wing; Santana, Patricia A; Scully, Robert R

    2013-04-01

    Brief exposures of Apollo astronauts to lunar dust occasionally elicited upper respiratory irritation; however, no limits were ever set for prolonged exposure to lunar dust. The United States and other space faring nations intend to return to the moon for extensive exploration within a few decades. In the meantime, habitats for that exploration, whether mobile or fixed, must be designed to limit human exposure to lunar dust to safe levels. Herein we estimate safe exposure limits for lunar dust collected during the Apollo 14 mission. We instilled three respirable-sized (∼2 μ mass median diameter) lunar dusts (two ground and one unground) and two standard dusts of widely different toxicities (quartz and TiO₂) into the respiratory system of rats. Rats in groups of six were given 0, 1, 2.5 or 7.5 mg of the test dust in a saline-Survanta® vehicle, and biochemical and cellular biomarkers of toxicity in lung lavage fluid were assayed 1 week and one month after instillation. By comparing the dose--response curves of sensitive biomarkers, we estimated safe exposure levels for astronauts and concluded that unground lunar dust and dust ground by two different methods were not toxicologically distinguishable. The safe exposure estimates were 1.3 ± 0.4 mg/m³ (jet-milled dust), 1.0 ± 0.5 mg/m³ (ball-milled dust) and 0.9 ± 0.3 mg/m³ (unground, natural dust). We estimate that 0.5-1 mg/m³ of lunar dust is safe for periodic human exposures during long stays in habitats on the lunar surface.

  3. The assessment of neonates’ exposure to traumatic factors in the cardiac ward within the first 24 hours of hospitalization

    Directory of Open Access Journals (Sweden)

    Grażyna Cepuch

    2016-03-01

    Full Text Available Introduction: During the first 24 hours of hospitalization, neonates with ductus-dependent CHD are exposed to a number of traumatic impulses arising from the need for necessary care and therapeutic procedures. Material and methods: The studied group consisted of neonates in a stable condition, suffering from ductusdependent CHD, monitored from the first to the fifth day of their life. The research involved the observation of 10 patients of the cardiac ward at the University Children’s Hospital. The research was carried out by means of the following methods: observation with available assessment tools, such as author’s questionnaire, CRIES scale, sound level meter and stopper. Results: The total number of all procedures performed on the group of 10 neonates amounted to 622 per day. The average number of invasive procedures per day performed on one patient was 6.6, while the procedures connected with touching averaged at 57.3. The average daily noise level amounted to 72.2 dB; the total daily time of exposure to artificial light averaged at 87 minutes, with the average duration of a single lighting episode lasting 14.6 minutes. The average pain level of a neonate connected with chosen invasive procedures fell between 5 and 7 points in the CRIES scale. Conclusions: The impact of traumatic factors disrupts the process of adaptation, may adversely influence further development of central nervous system, perception and sense organs and disturbs psychological development.

  4. Estimation of lung cancer risk from environmental exposure to airborne plutonium from the Rocky Flats Plant

    International Nuclear Information System (INIS)

    Sutherland, J.V.

    1983-01-01

    A three-phase study was undertaken to (1) determine the nature of disagreement among scientists concerning risk of environmental release of plutonium, (2) develop an analytic procedure for determining risk based on clearly stated principles defensible by reference to the literature, and (3) develop estimates of radiation dose to the lung from exposure to plutonium in ambient air for the purpose of evaluating risk to an individual with a specified age and smoking history. Eleven epidemiologists, biostatisticians and radiation scientists participated in Phase I of the study. It was shown that no clearly stated analytical principles for risk estimation were in common use, resulting in widely divergent risk estimates. Five of these disagreeing scientists in Phase I (including all cancer epidemiologists in the Denver metropolitan area) were chosen for Phase II of the study. A single analytic procedure was developed which was unanimously agreed upon. This procedure was dependent on the estimate of dose to the lung from ambient air levels of Rocky Flats plutonium. In Phase III of the study, a panel of four radiation scientists developed a procedure for estimation of dose to the lung from chronic exposure to plutonium ambient air levels. Results from all phases of the study were used to develop a method for estimation of relative risk of lung cancer for an individual, given plutonium dose to the lung, age, smoking history and other radiation exposure

  5. An Updated Algorithm for Estimation of Pesticide Exposure Intensity in the Agricultural Health Study

    Directory of Open Access Journals (Sweden)

    Aaron Blair

    2011-12-01

    Full Text Available An algorithm developed to estimate pesticide exposure intensity for use in epidemiologic analyses was revised based on data from two exposure monitoring studies. In the first study, we estimated relative exposure intensity based on the results of measurements taken during the application of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D (n = 88 and the insecticide chlorpyrifos (n = 17. Modifications to the algorithm weighting factors were based on geometric means (GM of post-application urine concentrations for applicators grouped by application method and use of chemically-resistant (CR gloves. Measurement data from a second study were also used to evaluate relative exposure levels associated with airblast as compared to hand spray application methods. Algorithm modifications included an increase in the exposure reduction factor for use of CR gloves from 40% to 60%, an increase in the application method weight for boom spray relative to in-furrow and for air blast relative to hand spray, and a decrease in the weight for mixing relative to the new weights assigned for application methods. The weighting factors for the revised algorithm now incorporate exposure measurements taken on Agricultural Health Study (AHS participants for the application methods and personal protective equipment (PPE commonly reported by study participants.

  6. Use of photographic film to estimate exposure near the Three Mile Island Nuclear Power Station

    International Nuclear Information System (INIS)

    Shuping, R.E.

    1981-02-01

    This report documents the methodology and results of a Bureau of Radiological Health study of the use of photographic film samples for estimating exposure levels near the Three Mile Island nuclear power station. The study was conducted to provide an independent assessment of the radiation levels near TMI following the accident on March 28, 1979

  7. Estimating overall exposure effects for the clustered and censored outcome using random effect Tobit regression models.

    Science.gov (United States)

    Wang, Wei; Griswold, Michael E

    2016-11-30

    The random effect Tobit model is a regression model that accommodates both left- and/or right-censoring and within-cluster dependence of the outcome variable. Regression coefficients of random effect Tobit models have conditional interpretations on a constructed latent dependent variable and do not provide inference of overall exposure effects on the original outcome scale. Marginalized random effects model (MREM) permits likelihood-based estimation of marginal mean parameters for the clustered data. For random effect Tobit models, we extend the MREM to marginalize over both the random effects and the normal space and boundary components of the censored response to estimate overall exposure effects at population level. We also extend the 'Average Predicted Value' method to estimate the model-predicted marginal means for each person under different exposure status in a designated reference group by integrating over the random effects and then use the calculated difference to assess the overall exposure effect. The maximum likelihood estimation is proposed utilizing a quasi-Newton optimization algorithm with Gauss-Hermite quadrature to approximate the integration of the random effects. We use these methods to carefully analyze two real datasets. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal

    2017-01-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth...... cohort, 275 and 349 participated in clinical examinations and provided blood samples at ages 18 months and 5 years. PFAS concentrations were measured at birth and at the clinical examinations. Using information on duration of breastfeeding, serum-PFAS concentration profiles during infancy were estimated......, with decreases by up to about 20% for each two-fold higher exposure, while associations for serum concentrations at ages 18 months and 5 years were weaker. Modeling of serum-PFAS concentration showed levels for age 18 months that were similar to those measured. Concentrations estimated for ages 3 and 6 months...

  9. Accounting for multiple climate components when estimating climate change exposure and velocity

    Science.gov (United States)

    Nadeau, Christopher P.; Fuller, Angela K.

    2015-01-01

    The effect of anthropogenic climate change on organisms will likely be related to climate change exposure and velocity at local and regional scales. However, common methods to estimate climate change exposure and velocity ignore important components of climate that are known to affect the ecology and evolution of organisms.We develop a novel index of climate change (climate overlap) that simultaneously estimates changes in the means, variation and correlation between multiple weather variables. Specifically, we estimate the overlap between multivariate normal probability distributions representing historical and current or projected future climates. We provide methods for estimating the statistical significance of climate overlap values and methods to estimate velocity using climate overlap.We show that climates have changed significantly across 80% of the continental United States in the last 32 years and that much of this change is due to changes in the variation and correlation between weather variables (two statistics that are rarely incorporated into climate change studies). We also show that projected future temperatures are predicted to be locally novel (using climate overlap compared to 1·4 km yr−1 when estimated using traditional methods.Our results suggest that accounting for changes in the means, variation and correlation between multiple weather variables can dramatically affect estimates of climate change exposure and velocity. These climate components are known to affect the ecology and evolution of organisms, but are ignored by most measures of climate change. We conclude with a set of future directions and recommend future work to determine which measures of climate change exposure and velocity are most related to biological responses to climate change.

  10. Computed tomography to estimate cardiac preload and extravascular lung water. A retrospective analysis in critically ill patients

    Directory of Open Access Journals (Sweden)

    Schmid Roland M

    2011-05-01

    Full Text Available Abstract Background In critically ill patients intravascular volume status and pulmonary edema need to be quantified as soon as possible. Many critically ill patients undergo a computed tomography (CT-scan of the thorax after admission to the intensive care unit (ICU. This study investigates whether CT-based estimation of cardiac preload and pulmonary hydration can accurately assess volume status and can contribute to an early estimation of hemodynamics. Methods Thirty medical ICU patients. Global end-diastolic volume index (GEDVI and extravascular lung water index (EVLWI were assessed using transpulmonary thermodilution (TPTD serving as reference method (with established GEDVI/EVLWI normal values. Central venous pressure (CVP was determined. CT-based estimation of GEDVI/EVLWI/CVP by two different radiologists (R1, R2 without analyzing software. Primary endpoint: predictive capabilities of CT-based estimation of GEDVI/EVLWI/CVP compared to TPTD and measured CVP. Secondary endpoint: interobserver correlation and agreement between R1 and R2. Results Accuracy of CT-estimation of GEDVI ( 800 mL/m2 was 33%(R1/27%(R2. For R1 and R2 sensitivity for diagnosis of low GEDVI (2 was 0% (specificity 100%. Sensitivity for prediction of elevated GEDVI (> 800 mL/m2 was 86%(R1/57%(R2 with a specificity of 57%(R1/39%(R2 (positive predictive value 38%(R1/22%(R2; negative predictive value 93%(R1/75%(R2. Estimated CT-GEDVI and TPTD-GEDVI were significantly different showing an overestimation of GEDVI by the radiologists (R1: mean difference ± standard error (SE: 191 ± 30 mL/m2, p 2, p 10 mL/kg was 30% for R1 and 40% for R2. CT-EVLWI and TPTD-EVLWI were significantly different (R1: mean difference ± SE: 3.3 ± 1.2 mL/kg, p = 0.013; R2: mean difference ± SE: 2.8 ± 1.1 mL/kg, p = 0.021. Again ccc was low with -0.02 (R1; 95% CI: -0.20 to +0.13, BCF = 0.44 and +0.14 (R2; 95% CI: -0.05 to +0.32, BCF = 0.53. GEDVI, EVLWI and CVP estimations of R1 and R2 showed a poor

  11. Radiotherapy verification film for estimating cumulative entrance skin exposure for fluoroscopic examinations

    International Nuclear Information System (INIS)

    Geise, R.A.; Ansel, H.J.

    1990-01-01

    Measurement of skin entrance exposures during fluoroscopic procedures is complicated by the use of automatic exposure control devices and the presence of contrast media. Due to variability in positioning spot films from patient to patient, standard dosimeters, such as thermoluminescent, cannot be properly placed on the skin prior to examination. Prepackaged film of the type used for portal verification in radiation therapy held next to the patient's skin in a specially modified patient examination gown was found to be useful for determining the entrance skin exposure from both fluoroscopy and spot films during air contrast barium enema exams. The usable sensitivity range of this film has been found satisfactory for exposure measurements at exposures and kVps typically used for gastrointestinal fluoroscopic procedures. Errors in exposure estimates due to changes in film speed and contrast with kVp are less than 5% for the range of kVps used. Errors from variations in beam quality due to the adjacency of scattering material are approximately 5%. Entrance exposures determined with film agreed with those determined from TLD measurements to within 21%, with an average difference of 9%

  12. Estimation of occupational and nonoccupational nitrogen dioxide exposure for Korean taxi drivers using a microenvironmental model

    International Nuclear Information System (INIS)

    Son, Busoon; Yang, Wonho; Breysse, Patrick; Chung, Taewoong; Lee, Youngshin

    2004-01-01

    Occupational and nonoccupational personal nitrogen dioxide (NO 2 ) exposures were measured using passive samplers for 31 taxi drivers in Asan and Chunan, Korea. Exposures were also estimated using a microenvironmental time-weighted average model based on indoor, outdoor and inside the taxi area measurements. Mean NO 2 indoor and outdoor concentrations inside and outside the taxi drivers' houses were 24.7±10.7 and 23.3±8.3 ppb, respectively, with a mean indoor to outdoor NO 2 ratio of 1.1. Mean personal NO 2 exposure of taxi drivers was 30.3±9.7 ppb. Personal NO 2 exposures for drivers were more strongly correlated with interior vehicle NO 2 levels (r=0.89) rather than indoor residential NO 2 levels (r=0.74) or outdoor NO 2 levels (r=0.71). The main source of NO 2 exposure for taxi drivers was considered to be occupational driving. Interestingly, the NO 2 exposures for drivers' using LPG-fueled vehicles (26.3±1.3 ppb) were significantly lower than those (38.1±1.3 ppb) using diesel-fueled vehicle (P 2 exposure with indoor and outdoor NO 2 levels of the residence, and interior vehicle NO 2 levels (P 2 levels because they drive diesel-using vehicles outdoors in Korea

  13. Planning Tools For Estimating Radiation Exposure At The National Ignition Facility

    International Nuclear Information System (INIS)

    Verbeke, J.; Young, M.; Brereton, S.; Dauffy, L.; Hall, J.; Hansen, L.; Khater, H.; Kim, S.; Pohl, B.; Sitaraman, S.

    2010-01-01

    A set of computational tools was developed to help estimate and minimize potential radiation exposure to workers from material activation in the National Ignition Facility (NIF). AAMI (Automated ALARA-MCNP Interface) provides an efficient, automated mechanism to perform the series of calculations required to create dose rate maps for the entire facility with minimal manual user input. NEET (NIF Exposure Estimation Tool) is a web application that combines the information computed by AAMI with a given shot schedule to compute and display the dose rate maps as a function of time. AAMI and NEET are currently used as work planning tools to determine stay-out times for workers following a given shot or set of shots, and to help in estimating integrated doses associated with performing various maintenance activities inside the target bay. Dose rate maps of the target bay were generated following a low-yield 10 16 D-T shot and will be presented in this paper.

  14. High-pitch computed tomography coronary angiography-a new dose-saving algorithm: estimation of radiation exposure.

    Science.gov (United States)

    Ketelsen, Dominik; Buchgeister, Markus; Korn, Andreas; Fenchel, Michael; Schmidt, Bernhard; Flohr, Thomas G; Thomas, Christoph; Schabel, Christoph; Tsiflikas, Ilias; Syha, Roland; Claussen, Claus D; Heuschmid, Martin

    2012-01-01

    Purpose. To estimate effective dose and organ equivalent doses of prospective ECG-triggered high-pitch CTCA. Materials and Methods. For dose measurements, an Alderson-Rando phantom equipped with thermoluminescent dosimeters was used. The effective dose was calculated according to ICRP 103. Exposure was performed on a second-generation dual-source scanner (SOMATOM Definition Flash, Siemens Medical Solutions, Germany). The following scan parameters were used: 320 mAs per rotation, 100 and 120 kV, pitch 3.4 for prospectively ECG-triggered high-pitch CTCA, scan range of 13.5 cm, collimation 64 × 2 × 0.6 mm with z-flying focal spot, gantry rotation time 280 ms, and simulated heart rate of 60 beats per minute. Results. Depending on the applied tube potential, the effective whole-body dose of the cardiac scan ranged from 1.1 mSv to 1.6 mSv and from 1.2 to 1.8 mSv for males and females, respectively. The radiosensitive breast tissue in the range of the primary beam caused an increased female-specific effective dose of 8.6%±0.3% compared to males. Decreasing the tube potential, a significant reduction of the effective dose of 35.8% and 36.0% can be achieved for males and females, respectively (P < 0.001). Conclusion. The radiologist and the CT technician should be aware of this new dose-saving strategy to keep the radiation exposure as low as reasonablly achievable.

  15. ESTIMATION OF EXPOSURE DOSES FOR THE SAFE MANAGEMENT OF NORM WASTE DISPOSAL.

    Science.gov (United States)

    Jeong, Jongtae; Ko, Nak Yul; Cho, Dong-Keun; Baik, Min Hoon; Yoon, Ki-Hoon

    2018-03-16

    Naturally occurring radioactive materials (NORM) wastes with different radiological characteristics are generated in several industries. The appropriate options for NORM waste management including disposal options should be discussed and established based on the act and regulation guidelines. Several studies calculated the exposure dose and mass of NORM waste to be disposed in landfill site by considering the activity concentration level and exposure dose. In 2012, the Korean government promulgated an act on the safety control of NORM around living environments to protect human health and the environment. For the successful implementation of this act, we suggest a reference design for a landfill for the disposal of NORM waste. Based on this reference landfill, we estimate the maximum exposure doses and the relative impact of each pathway to exposure dose for three scenarios: a reference scenario, an ingestion pathway exclusion scenario, and a low leach rate scenario. Also, we estimate the possible quantity of NORM waste disposal into a landfill as a function of the activity concentration level of U series, Th series and 40K and two kinds of exposure dose levels, 1 and 0.3 mSv/y. The results of this study can be used to support the establishment of technical bases of the management strategy for the safe disposal of NORM waste.

  16. Estimating mortality derived from indoor exposure to particles of outdoor origin.

    Directory of Open Access Journals (Sweden)

    Wenjing Ji

    Full Text Available Following an extensive review of the literature, we further analyze the published data to examine the health effects of indoor exposure to particulate matter (PM of outdoor origin. We obtained data on all-cause, cardiovascular, and respiratory mortality per 10 μg/m3 increase in outdoor PM10 or PM2.5; the infiltration factors for buildings; and estimated time spent outdoors by individuals in the United States, Europe, China, and globally. These data were combined log-linear exposure-response model to estimate the all-cause, cardiovascular, and respiratory mortality of exposure to indoor PM pollution of outdoor origin. Indoor PM pollution of outdoor origin is a cause of considerable mortality, accounting for 81% to 89% of the total increase in mortality associated with exposure to outdoor PM pollution for the studied regions. The findings suggest that enhancing the capacity of buildings to protect occupants against exposure to outdoor PM pollution has significant potential to improve public health outcomes.

  17. Estimated drinking water fluoride exposure and risk of hip fracture: a cohort study.

    Science.gov (United States)

    Näsman, P; Ekstrand, J; Granath, F; Ekbom, A; Fored, C M

    2013-11-01

    The cariostatic benefit from water fluoridation is indisputable, but the knowledge of possible adverse effects on bone and fracture risk due to fluoride exposure is ambiguous. The association between long-term (chronic) drinking water fluoride exposure and hip fracture (ICD-7-9: '820' and ICD-10: 'S72.0-S72.2') was assessed in Sweden using nationwide registers. All individuals born in Sweden between January 1, 1900 and December 31, 1919, alive and living in their municipality of birth at the time of start of follow-up, were eligible for this study. Information on the study population (n = 473,277) was linked among the Swedish National In-Patient Register (IPR), the Swedish Cause of Death Register, and the Register of Population and Population Changes. Estimated individual drinking water fluoride exposure was stratified into 4 categories: very low, hip fracture. The risk estimates did not change in analyses restricted to only low-trauma osteoporotic hip fractures. Chronic fluoride exposure from drinking water does not seem to have any important effects on the risk of hip fracture, in the investigated exposure range.

  18. The associations between birth outcomes and satellite-estimated maternal PM2.5 exposure in Shanghai, China

    Science.gov (United States)

    Xiao, Q.; Liu, Y.; Strickland, M. J.; Chang, H. H.; Kan, H.

    2017-12-01

    Background: Satellite remote sensing data have been employed for air pollution exposure assessment, with the intent of better characterizing exposure spatio-temproal variations. However, non-random missingness in satellite data may lead to exposure error. Objectives: We explored the differences in health effect estimates due to different exposure metrics, with and without satellite data, when analyzing the associations between maternal PM2.5 exposure and birth outcomes. Methods: We obtained birth registration records of 132,783 singleton live births during 2011-2014 in Shanghai. Trimester-specific and total pregnancy exposures were estimated from satellite PM2.5 predictions with missingness, gap-filled satellite PM2.5 predictions with complete coverage and regional average PM2.5 measurements from monitoring stations. Linear regressions estimated associations between birth weight and maternal PM2.5 exposure. Logistic regressions estimated associations between preterm birth and the first and second trimester exposure. Discrete-time models estimated third trimester and total pregnancy associations with preterm birth. Effect modifications by maternal age and parental education levels were investigated. Results: we observed statistically significant associations between maternal PM2.5 exposure during all exposure windows and adverse birth outcomes. A 10 µg/m3 increase in pregnancy PM2.5 exposure was associated with a 12.85 g (95% CI: 18.44, 7.27) decrease in birth weight for term births, and a 27% (95% CI: 20%, 36%) increase in the risk of preterm birth. Greater effects were observed between first and third trimester exposure and birth weight, as well as between first trimester exposure and preterm birth. Mothers older than 35 years and without college education tended to have higher associations with preterm birth. Conclusions: Gap-filled satellite data derived PM2.5 exposure estimates resulted in reduced exposure error and more precise health effect estimates.

  19. Estimating Inorganic Arsenic Exposure from U.S. Rice and Total Water Intakes

    OpenAIRE

    Mantha, Madhavi; Yeary, Edward; Trent, John; Creed, Patricia A.; Kubachka, Kevin; Hanley, Traci; Shockey, Nohora; Heitkemper, Douglas; Caruso, Joseph; Xue, Jianping; Rice, Glenn; Wymer, Larry; Creed, John T.

    2017-01-01

    Background: Among nonoccupationally exposed U.S. residents, drinking water and diet are considered primary exposure pathways for inorganic arsenic (iAs). In drinking water, iAs is the primary form of arsenic (As), while dietary As speciation techniques are used to differentiate iAs from less toxic arsenicals in food matrices. Objectives: Our goal was to estimate the distribution of iAs exposure rates from drinking water intakes and rice consumption in the U.S. population and ethnic- and age-b...

  20. Music exposure induced prolongation of cardiac allograft survival and generated regulatory CD4⁺ cells in mice.

    Science.gov (United States)

    Uchiyama, M; Jin, X; Zhang, Q; Amano, A; Watanabe, T; Niimi, M

    2012-05-01

    In clinical practice, music has been used to decrease stress, heart rate, and blood pressure and to provide a distraction from disease symptoms. We investigated sound effects on alloimmune responses in murine heart transplantation. Naïve and eardrum-ruptured CBA/N (CBA, H2(K)) underwent transplantation of a C57BL/6 (B6, H2(b)) heart and were exposed to 1 of 3 types of music-opera (La Traviata), classical (Mozart), and New Age (Enya)-or 1 of 6 different single sound frequencies for 7 days. An adoptive transfer study was performed to determine whether regulatory cells were generated in allograft recipients. Cell-proliferation, cytokine, and flow cytometry assessments were also performed. CBA recipients of a B6 graft exposed to opera and classical music had significantly prolonged allograft survival (median survival times [MSTs], 26.5 and 20 days, respectively), whereas those exposed to 6 single sound frequencies and New Age did not (MSTs, 7, 8, 9, 8, 8, 8, and 11 days, respectively). Untreated and eardrum-ruptured CBA rejected B6 grafts acutely (MSTs, 7 and 8.5 days, respectively). Adoptive transfer of whole splenocytes, CD4(+) cells, and CD4(+)CD25(+) cells from opera-exposed primary recipients resulted in significantly prolonged allograft survival in naive secondary recipients (MSTs, 36, 68, and >50 days, respectively). Cell-proliferation, interleukin (IL)-2 and interferon-γ were suppressed in opera-exposed mice, whereas IL-4 and IL-10 from opera-exposed recipients were up-regulated. Flow cytometry studies showed an increased CD4(+)CD25(+)Foxp3(+) cell population in splenocytes from opera-exposed mice. In conclusion, exposure to some types of music may induce prolonged survival of fully allogeneic cardiac allografts and generate CD4(+)CD25(+)Foxp3(+) regulatory cells. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. A comparison of methods for calculating population exposure estimates of daily weather for health research

    Directory of Open Access Journals (Sweden)

    Dear Keith BG

    2006-09-01

    Full Text Available Abstract Background To explain the possible effects of exposure to weather conditions on population health outcomes, weather data need to be calculated at a level in space and time that is appropriate for the health data. There are various ways of estimating exposure values from raw data collected at weather stations but the rationale for using one technique rather than another; the significance of the difference in the values obtained; and the effect these have on a research question are factors often not explicitly considered. In this study we compare different techniques for allocating weather data observations to small geographical areas and different options for weighting averages of these observations when calculating estimates of daily precipitation and temperature for Australian Postal Areas. Options that weight observations based on distance from population centroids and population size are more computationally intensive but give estimates that conceptually are more closely related to the experience of the population. Results Options based on values derived from sites internal to postal areas, or from nearest neighbour sites – that is, using proximity polygons around weather stations intersected with postal areas – tended to include fewer stations' observations in their estimates, and missing values were common. Options based on observations from stations within 50 kilometres radius of centroids and weighting of data by distance from centroids gave more complete estimates. Using the geographic centroid of the postal area gave estimates that differed slightly from the population weighted centroids and the population weighted average of sub-unit estimates. Conclusion To calculate daily weather exposure values for analysis of health outcome data for small areas, the use of data from weather stations internal to the area only, or from neighbouring weather stations (allocated by the use of proximity polygons, is too limited. The most

  2. Cardiac CT

    International Nuclear Information System (INIS)

    Dewey, Marc

    2011-01-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  3. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  4. Improved exposure estimation in soil screening and cleanup criteria for volatile organic chemicals.

    Science.gov (United States)

    DeVaull, George E

    2017-09-01

    Soil cleanup criteria define acceptable concentrations of organic chemical constituents for exposed humans. These criteria sum the estimated soil exposure over multiple pathways. Assumptions for ingestion, dermal contact, and dust exposure generally presume a chemical persists in surface soils at a constant concentration level for the entire exposure duration. For volatile chemicals, this is an unrealistic assumption. A calculation method is presented for surficial soil criteria that include volatile depletion of chemical for these uptake pathways. The depletion estimates compare favorably with measured concentration profiles and with field measurements of soil concentration. Corresponding volatilization estimates compare favorably with measured data for a wide range of volatile and semivolatile chemicals, including instances with and without the presence of a mixed-chemical residual phase. Selected examples show application of the revised factors in estimating screening levels for benzene in surficial soils. Integr Environ Assess Manag 2017;13:861-869. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

  5. Estimation of respirable dust exposure among coal miners in South Africa.

    Science.gov (United States)

    Naidoo, Rajen; Seixas, Noah; Robins, Thomas

    2006-06-01

    The use of retrospective occupational hygiene data for epidemiologic studies is useful in determining exposure-outcome relationships, but the potential for exposure misclassification is high. Although dust sampling in the South African coal industry has been a legal requirement for several decades, these historical data are not readily adequate for estimating past exposures. This study describes the respirable coal mine dust levels in three South African coal mines over time. Each of the participating mining operations had well-documented dust sampling information that was used to describe historical trends in dust exposure. Investigator-collected personal dust samples were taken using standardized techniques from the face, backbye (underground jobs not at the coal face), and surface from 50 miners at each mine, repeated over three sampling cycles. Job histories and exposure information was obtained from a sample of 684 current miners and 188 ex-miners. Linear models were developed to estimate the exposure levels associated with work in each mine, exposure zone, and over time using a combination of operator-collected historical data and investigator-collected samples. The estimated levels were then combined with work history information to calculate cumulative exposure metrics for the miner cohort. The mean historical and investigator-collected respirable dust levels were within international norms and South African standards. Silica content of the dust samples was also below the 5% regulatory action level. Mean respirable dust concentrations at the face, based on investigator-collected samples, were 0.9 mg/m(3), 1.3 mg/m(3), and 1.9 mg/m(3) at Mines 1, 2, and 3, respectively. The operator-collected samples showed considerable variability across exposure zones, mines, and time, with the annual means at the face ranging from 0.4 mg/m(3) to 2.9 mg/m(3). Statistically significant findings were found between operator- and investigator-collected dust samples. Model

  6. Particulate Matter Exposure and Preterm Birth: Estimates of U.S. Attributable Burden and Economic Costs.

    Science.gov (United States)

    Trasande, Leonardo; Malecha, Patrick; Attina, Teresa M

    2016-12-01

    Preterm birth (PTB) rates (11.4% in 2013) in the United States remain high and are a substantial cause of morbidity. Studies of prenatal exposure have associated particulate matter ≤ 2.5 μm in diameter (PM2.5) and other ambient air pollutants with adverse birth outcomes; yet, to our knowledge, burden and costs of PM2.5-attributable PTB have not been estimated in the United States. We aimed to estimate burden of PTB in the United States and economic costs attributable to PM2.5 exposure in 2010. Annual deciles of PM2.5 were obtained from the U.S. Environmental Protection Agency. We converted PTB odds ratio (OR), identified in a previous meta-analysis (1.15 per 10 μg/m3 for our base case, 1.07-1.16 for low- and high-end scenarios) to relative risk (RRs), to obtain an estimate that better represents the true relative risk. A reference level (RL) of 8.8 μg/m3 was applied. We then used the RR estimates and county-level PTB prevalence to quantify PM2.5-attributable PTB. Direct medical costs were obtained from the 2007 Institute of Medicine report, and lost economic productivity (LEP) was estimated using a meta-analysis of PTB-associated IQ loss, and well-established relationships of IQ loss with LEP. All costs were calculated using 2010 dollars. An estimated 3.32% of PTBs nationally (corresponding to 15,808 PTBs) in 2010 could be attributed to PM2.5 (PM2.5 > 8.8 μg/m3). Attributable PTBs cost were estimated at $5.09 billion [sensitivity analysis (SA): $2.43-9.66 B], of which $760 million were spent for medical care (SA: $362 M-1.44 B). The estimated PM2.5 attributable fraction (AF) of PTB was highest in urban counties, with highest AFs in the Ohio Valley and the southern United States. PM2.5 may contribute substantially to burden and costs of PTB in the United States, and considerable health and economic benefits could be achieved through environmental regulatory interventions that reduce PM2.5 exposure in pregnancy. Citation: Trasande L, Malecha P, Attina TM. 2016

  7. Development and Validation of a Heart Atlas to Study Cardiac Exposure to Radiation Following Treatment for Breast Cancer

    International Nuclear Information System (INIS)

    Feng, Mary; Moran, Jean M.; Koelling, Todd; Chughtai, Aamer; Chan, June L.; Freedman, Laura; Hayman, James A.; Jagsi, Reshma; Jolly, Shruti; Larouere, Janice; Soriano, Julie; Marsh, Robin; Pierce, Lori J.

    2011-01-01

    Purpose: Cardiac toxicity is an important sequela of breast radiotherapy. However, the relationship between dose to cardiac structures and subsequent toxicity has not been well defined, partially due to variations in substructure delineation, which can lead to inconsistent dose reporting and the failure to detect potential correlations. Here we have developed a heart atlas and evaluated its effect on contour accuracy and concordance. Methods and Materials: A detailed cardiac computed tomography scan atlas was developed jointly by cardiology, cardiac radiology, and radiation oncology. Seven radiation oncologists were recruited to delineate the whole heart, left main and left anterior descending interventricular branches, and right coronary arteries on four cases before and after studying the atlas. Contour accuracy was assessed by percent overlap with gold standard atlas volumes. The concordance index was also calculated. Standard radiation fields were applied. Doses to observer-contoured cardiac structures were calculated and compared with gold standard contour doses. Pre- and post-atlas values were analyzed using a paired t test. Results: The cardiac atlas significantly improved contour accuracy and concordance. Percent overlap and concordance index of observer-contoured cardiac and gold standard volumes were 2.3-fold improved for all structures (p < 0.002). After application of the atlas, reported mean doses to the whole heart, left main artery, left anterior descending interventricular branch, and right coronary artery were within 0.1, 0.9, 2.6, and 0.6 Gy, respectively, of gold standard doses. Conclusions: This validated University of Michigan cardiac atlas may serve as a useful tool in future studies assessing cardiac toxicity and in clinical trials which include dose volume constraints to the heart.

  8. Estimation of utility values from visual analog scale measures of health in patients undergoing cardiac surgery

    Directory of Open Access Journals (Sweden)

    Oddershede L

    2014-01-01

    Full Text Available Lars Oddershede,1,2 Jan Jesper Andreasen,1 Lars Ehlers2 1Department of Cardiothoracic Surgery, Center for Cardiovascular Research, Aalborg University Hospital, Aalborg, Denmark; 2Danish Center for Healthcare Improvements, Faculty of Social Sciences and Faculty of Health Sciences, Aalborg University, Aalborg East, Denmark Introduction: In health economic evaluations, mapping can be used to estimate utility values from other health outcomes in order to calculate quality adjusted life-years. Currently, no methods exist to map visual analog scale (VAS scores to utility values. This study aimed to develop and propose a statistical algorithm for mapping five dimensions of health, measured on VASs, to utility scores in patients suffering from cardiovascular disease. Methods: Patients undergoing coronary artery bypass grafting at Aalborg University Hospital in Denmark were asked to score their health using the five VAS items (mobility, self-care, ability to perform usual activities, pain, and presence of anxiety or depression and the EuroQol 5 Dimensions questionnaire. Regression analysis was used to estimate four mapping models from patients' age, sex, and the self-reported VAS scores. Prediction errors were compared between mapping models and on subsets of the observed utility scores. Agreement between predicted and observed values was assessed using Bland–Altman plots. Results: Random effects generalized least squares (GLS regression yielded the best results when quadratic terms of VAS scores were included. Mapping models fitted using the Tobit model and censored least absolute deviation regression did not appear superior to GLS regression. The mapping models were able to explain approximately 63%–65% of the variation in the observed utility scores. The mean absolute error of predictions increased as the observed utility values decreased. Conclusion: We concluded that it was possible to predict utility scores from VAS scores of the five

  9. Estimate of Annual Ultraviolet-A Exposures in Cars in Australia

    International Nuclear Information System (INIS)

    Parisi, A.V.; Kimlin, M.G.

    2000-01-01

    The annual solar UVA exposures in four cars were estimated by measuring the UVA irradiances in the vehicles in each of the four seasons and in the morning, noon and afternoon. For the cars with untinted windows the maximum UVA irradiances in cars do not necessarily occur at noon when the outside irradiances are at their highest. Additionally, they do not occur in summer. The range of annual UVA exposures between 9:00 and 15:00 EST is 1918 to 6177 J.cm -2 for the cars without the after-market window tint. These correspond to 5% to 17% of the ambient UVA on a horizontal plane over the same period outside the cars. The range is for the different sites in the car. For the car with the after-market window tint, the range of the annual UVA exposures was 489 to 2969 J.cm -2 or 1% to 8% of the ambient UVA. (author)

  10. A computer-assisted procedure for estimating patient exposure and fetal dose in radiographic examinations

    International Nuclear Information System (INIS)

    Glaze, S.; Schneiders, N.; Bushong, S.C.

    1982-01-01

    A computer program for calculating patient entrance exposure and fetal dose for 11 common radiographic examinations was developed. The output intensity measured at 70 kVp and a 30-inch (76-cm) source-to-skin distance was entered into the program. The change in output intensity with changing kVp was examined for 17 single-phase and 12 three-phase x-ray units. The relationships obtained from a least squares regression analysis of the data, along with the technique factors for each examination, were used to calculate patient exposure. Fetal dose was estimated using published fetal dose in mrad (10 -5 Gy) per 1,000 mR (258 μC/kg) entrance exposure values. The computations are fully automated and individualized to each radiographic unit. The information provides a ready reference in large institutions and is particularly useful at smaller facilities that do not have available physicists who can make the calculations immediately

  11. A computer-assisted procedure for estimating patient exposure and fetal dose in radiographic examinations

    International Nuclear Information System (INIS)

    Glaze, S.; Schneiders, N.; Bushong, S.C.

    1982-01-01

    A computer program for calculating patient entrance exposure and fetal dose for 11 common radiographic examinations was developed. The output intensity measured at 70 kVp and a 30-inch (76-cm) source-to-skin distance was entered into the program. The change in output intensity with changing kVp was examined for 17 single-phase and 12 three-phase x-ray units. The relationships obtained from a least squares regression analysis of the data, along with the technique factors for each examination, were used to calculate patient exposure. Fetal dose was estimated using published fetal dose in mrad (10(-5) Gy) per 1,000 mR (258 microC/kg) entrance exposure values. The computations are fully automated and individualized to each radiographic unit. The information provides a ready reference in large institutions and is particularly useful at smaller facilities that do not have available physicians who can make the calculations immediately

  12. Recommendations for determining the surface contamination of the skin and estimating radiation exposure of the skin after contamination

    International Nuclear Information System (INIS)

    1989-01-01

    The recommendations are applicable to the determination of surface contaminations of the skin and to the estimation of the expected radiation exposure of the skin of contaminated persons. According to the present recommendations, the radiation exposure can only be estimated for the intact and healthy skin

  13. Acrylamide content in cigarette mainstream smoke and estimation of exposure to acrylamide from tobacco smoke in Poland

    Directory of Open Access Journals (Sweden)

    Hanna Mojska

    2016-07-01

    Our results demonstrate that tobacco smoke is a significant source of acrylamide and total exposure to acrylamide in the population of smokers, on average, is higher by more than 50% in comparison with non-smokers. Our estimation of exposure to acrylamide from tobacco smoke is the first estimation taking into account the actual determined acrylamide content in the cigarettes available on the market.

  14. Exposure Estimation for Risk Assessment of the Phthalate Incident in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chu-Chih Chen

    Full Text Available In May 2011, di(2-ethylhexyl phthalates (DEHP and, to a lesser extent, di-iso-nonyl phthalate (DiNP were found to have been illegally used for many years in Taiwan as clouding agents in foods including sports drinks, juice beverages, tea drinks, fruit jam/nectar/jelly, and health or nutrient supplements.To estimate the DEHP exposure for the study participants for the follow-up epidemiological study and health risk assessment.A total of 347 individuals possibly highly exposed to phthalate-tainted foods participated in the study. Exposure assessment was performed based on the participants' responses to a structured questionnaire, self-report of exposure history, urinary metabolite concentrations, and DEHP concentration information in 2449 food records. A Bayesian statistical approach using Markov chain Monte Carlo simulation was employed to deal with the uncertainties in the DEHP concentrations of the contaminated foods and the participants' likelihood of being exposed.An estimated 37% and 15% of children younger than 12 years old were exposed to DEHP at medium (20-50 μg / kg_bw / day and high AvDIs (50-100 μg / kg_bw / day, respectively, prior to the episode (9% and 3% in adults, respectively. Moreover, 11% of children and 1% of adults were highly exposed (> 100 μg / kg_bw / day, with a maximum of 414.1 μg / kg_bw / day and 126.4 μg / kg_bw / day, respectively.The phthalate exposure-associated adverse health effects for these participants warrant further investigation. The estimation procedure may be applied to other exposure assessment with various sources of uncertainties.

  15. Combined methodology for estimating dose rates and health effects from exposure to radioactive pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, D.E. Jr.; Leggett, R.W.; Yalcintas, M.G.

    1980-12-01

    The work described in the report is basically a synthesis of two previously existing computer codes: INREM II, developed at the Oak Ridge National Laboratory (ORNL); and CAIRD, developed by the Environmental Protection Agency (EPA). The INREM II code uses contemporary dosimetric methods to estimate doses to specified reference organs due to inhalation or ingestion of a radionuclide. The CAIRD code employs actuarial life tables to account for competing risks in estimating numbers of health effects resulting from exposure of a cohort to some incremental risk. The combined computer code, referred to as RADRISK, estimates numbers of health effects in a hypothetical cohort of 100,000 persons due to continuous lifetime inhalation or ingestion of a radionuclide. Also briefly discussed in this report is a method of estimating numbers of health effects in a hypothetical cohort due to continuous lifetime exposure to external radiation. This method employs the CAIRD methodology together with dose conversion factors generated by the computer code DOSFACTER, developed at ORNL; these dose conversion factors are used to estimate dose rates to persons due to radionuclides in the air or on the ground surface. The combination of the life table and dosimetric guidelines for the release of radioactive pollutants to the atmosphere, as required by the Clean Air Act Amendments of 1977.

  16. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years.

    Science.gov (United States)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal; Nielsen, Flemming; Mogensen, Ulla B; Timmermann, Amalie; Budtz-Jørgensen, Esben

    2017-12-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth cohort, 275 and 349 participated in clinical examinations and provided blood samples at ages 18 months and 5 years. PFAS concentrations were measured at birth and at the clinical examinations. Using information on duration of breastfeeding, serum-PFAS concentration profiles during infancy were estimated. As outcomes, serum concentrations of antibodies against tetanus and diphtheria vaccines were determined at age 5. Data from a previous cohort born eight years earlier were available for pooled analyses. Pre-natal exposure showed inverse associations with the antibody concentrations five years later, with decreases by up to about 20% for each two-fold higher exposure, while associations for serum concentrations at ages 18 months and 5 years were weaker. Modeling of serum-PFAS concentration showed levels for age 18 months that were similar to those measured. Concentrations estimated for ages 3 and 6 months showed the strongest inverse associations with antibody concentrations at age 5 years, particularly for tetanus. Joint analyses showed statistically significant decreases in tetanus antibody concentrations by 19-29% at age 5 for each doubling of the PFAS exposure in early infancy. These findings support the notion that the developing adaptive immune system is particularly vulnerable to immunotoxicity during infancy. This vulnerability appears to be the greatest during the first 6 months after birth, where PFAS exposures are affected by breast-feeding.

  17. LEA: An Algorithm to Estimate the Level of Location Exposure in Infrastructure-Based Wireless Networks

    Directory of Open Access Journals (Sweden)

    Francisco Garcia

    2017-01-01

    Full Text Available Location privacy in wireless networks is nowadays a major concern. This is due to the fact that the mere fact of transmitting may allow a network to pinpoint a mobile node. We consider that a first step to protect a mobile node in this situation is to provide it with the means to quantify how accurately a network establishes its position. To achieve this end, we introduce the location-exposure algorithm (LEA, which runs on the mobile terminal only and whose operation consists of two steps. In the first step, LEA discovers the positions of nearby network nodes and uses this information to emulate how they estimate the position of the mobile node. In the second step, it quantifies the level of exposure by computing the distance between the position estimated in the first step and its true position. We refer to these steps as a location-exposure problem. We tested our proposal with simulations and testbed experiments. These results show the ability of LEA to reproduce the location of the mobile node, as seen by the network, and to quantify the level of exposure. This knowledge can help the mobile user decide which actions should be performed before transmitting.

  18. Estimating population exposure to power plant emissions using CALPUFF: a case study in Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Ying Zhou; Levy, J.I. [Harvard School of Public Health, Boston, MA (United States); Hammitt, J.K.; Evans, J.S. [Harvard Center for Risk Analysis, Boston, MA (United States)

    2003-02-01

    Epidemiological studies have shown a significant association between ambient particulate matter (PM) exposures and increased mortality and morbidity risk. Power plants are significant emitters of precursor gases of fine particulate matter. To evaluate the public health risk posed by power plants, it is necessary to evaluate population exposure to different pollutants. The concept of intake fraction (the fraction of a pollutant emitted that is eventually inhaled or ingested by a population) has been proposed to provide a simple summary measure of the relationship between emissions and exposure. Currently available intake fraction estimates from developing countries used models that look only at the near field impacts, which may not capture the full impact of a pollution source. This case study demonstrated how the intake fraction of power plant emissions in China can be calculated using a detailed long-range atmospheric dispersion model-CALPUFF. We found that the intake fraction of primary fine particles is roughly on the order of 10{sup -5}, while the intake fractions of sulfur dioxide, sulfate and nitrate are on the order of 10{sup -6}. These estimates are an order of magnitude higher than the US estimates. We also tested how sensitive the results were to key assumptions within the model. The size distribution of primary particles has a large impact on the intake fraction for primary particles while the background ammonia concentration is an important factor influencing the intake fraction of nitrate. The background ozone concentration has a moderate impact on the intake fraction of sulfate and nitrate. Our analysis shows that this approach is applicable to a developing country and it provides reasonable population exposure estimates. (author)

  19. Estimates of per capita exposure to substances migrating from canned foods and beverages.

    Science.gov (United States)

    Dionisi, G; Oldring, P K T

    2002-09-01

    A study was undertaken by European industry to estimate the consumption of canned beverages and foodstuffs. European can production data were used with adjustments for imports into and out of the EU. It was further assumed that can production, with adjustments, equalled consumption. Owing to the lack of actual consumption country-by-country or household-by-household data throughout Europe, only per capita estimates of consumption were possible. Data were compiled country-by-country for seven major can-producing EU Member States and for eight different types of canned food and two types of canned beverage (beer and soft drinks). The per capita consumption of canned foods was 1.1 cans/person/week, and consumption of canned fish was estimated as 2.2 kg/person/year. The estimate of per capita consumption of canned food was 62 g/person/day or 22.6 kg/person/year. Canned beverages account for about 60% of the consumption of canned foodstuffs. The usefulness of per capita consumption of beverages is questionable because consumption habits may vary more widely than those for canned foods. However, as the migration into beverages is insignificant, these data were added for completeness. Per capita consumption of canned beverages is 67 cans/person/year or 61 g/person/day. From the average can sizes, the surface area of the cans consumed was estimated. The per capita surface area exposure was 0.55 dm(2)/person/day for canned foods and 0.55 dm(2)/person/day for canned beverages, giving 1.1 dm(2)/person/day. Migration of a substance at 0.02 mg dm(2) gives an exposure of 0.01 mg/person/day assuming a per capita consumption, using a surface area model. Migration at 0.12 mg kg(-1) in food gives an exposure of 0.007 mg/person/day using a weight model. Both models assumed migration into all food types at the same level, which is highly unrealistic. Exposure to BADGE from canned foods has been used as a case study. The best estimate for a worst case per capita exposure to BADGE and

  20. Estimation of the Relative Contribution of Postprandial Glucose Exposure to Average Total Glucose Exposure in Subjects with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Bo Ahrén

    2016-01-01

    Full Text Available We hypothesized that the relative contribution of fasting plasma glucose (FPG versus postprandial plasma glucose (PPG to glycated haemoglobin (HbA1c could be calculated using an algorithm developed by the A1c-Derived Average Glucose (ADAG study group to make HbA1c values more clinically relevant to patients. The algorithm estimates average glucose (eAG exposure, which can be used to calculate apparent PPG (aPPG by subtracting FPG. The hypothesis was tested in a large dataset (comprising 17 studies from the vildagliptin clinical trial programme. We found that 24 weeks of treatment with vildagliptin monotherapy (n=2523 reduced the relative contribution of aPPG to eAG from 8.12% to 2.95% (by 64%, p<0.001. In contrast, when vildagliptin was added to metformin (n=2752, the relative contribution of aPPG to eAG insignificantly increased from 1.59% to 2.56%. In conclusion, glucose peaks, which are often prominent in patients with type 2 diabetes, provide a small contribution to the total glucose exposure assessed by HbA1c, and the ADAG algorithm is not robust enough to assess this small relative contribution in patients receiving combination therapy.

  1. Estimating the acute health effects of coarse particulate matter accounting for exposure measurement error.

    Science.gov (United States)

    Chang, Howard H; Peng, Roger D; Dominici, Francesca

    2011-10-01

    In air pollution epidemiology, there is a growing interest in estimating the health effects of coarse particulate matter (PM) with aerodynamic diameter between 2.5 and 10 μm. Coarse PM concentrations can exhibit considerable spatial heterogeneity because the particles travel shorter distances and do not remain suspended in the atmosphere for an extended period of time. In this paper, we develop a modeling approach for estimating the short-term effects of air pollution in time series analysis when the ambient concentrations vary spatially within the study region. Specifically, our approach quantifies the error in the exposure variable by characterizing, on any given day, the disagreement in ambient concentrations measured across monitoring stations. This is accomplished by viewing monitor-level measurements as error-prone repeated measurements of the unobserved population average exposure. Inference is carried out in a Bayesian framework to fully account for uncertainty in the estimation of model parameters. Finally, by using different exposure indicators, we investigate the sensitivity of the association between coarse PM and daily hospital admissions based on a recent national multisite time series analysis. Among Medicare enrollees from 59 US counties between the period 1999 and 2005, we find a consistent positive association between coarse PM and same-day admission for cardiovascular diseases.

  2. Effects of insecticide exposure on movement and population size estimates of predatory ground beetles (Coleoptera: Carabidae).

    Science.gov (United States)

    Prasifka, Jarrad R; Lopez, Miriam D; Hellmich, Richard L; Prasifka, Patricia L

    2008-01-01

    Estimates of arthropod population size may paradoxically increase following insecticide applications. Research with ground beetles (Coleoptera: Carabidae) suggests that such unusual results reflect increased arthropod movement and capture in traps rather than real changes in population size. However, it is unclear whether direct (hyperactivity) or indirect (prey-mediated) mechanisms produce increased movement. Video tracking of Scarites quadriceps Chaudior indicated that brief exposure to lambda-cyhalothrin or tefluthrin increased total distance moved, maximum velocity and percentage of time moving. Repeated measurements on individual beetles indicated that movement decreased 240 min after initial lambda-cyhalothrin exposure, but increased again following a second exposure, suggesting hyperactivity could lead to increased trap captures in the field. Two field experiments in which ground beetles were collected after lambda-cyhalothrin or permethrin application attempted to detect increases in population size estimates as a result of hyperactivity. Field trials used mark-release-recapture methods in small plots and natural carabid populations in larger plots, but found no significant short-term (<6 day) increases in beetle trap captures. The disagreement between laboratory and field results suggests mechanisms other than hyperactivity may better explain unusual changes in population size estimates. When traps are used as a primary sampling tool, unexpected population-level effects should be interpreted carefully or with additional data less influenced by arthropod activity.

  3. Estimation of Exposure Doses for Several Scenarios of the Landfill Disposal of NORM Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jong Tae; Ko, Nak Yul; Baik, Min Hoon [KAERI, Daejeon (Korea, Republic of); Yoon, Ki Hoon [Korea Institude of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-05-15

    The Act on safety control of radioactive materials around living environment was promulgated to protect citizen's health and environment in 2013. According to this Act, the integrated plan for radiation protection and the necessary safety guides for treatment, reuse, and disposal of NORM wastes have to be made. And NORM wastes have to be disposed in landfill sites by reducing the concentration of radionuclide, and they should not be reutilized. In this study, we estimated exposure doses for several scenarios for NORM (Naturally Occurring Radioactive Materials) waste disposal into a reference landfill site to check the radiological safety. Also, we estimated the amount of NORM wastes for different activity levels of important radionuclides in wastes to be disposed into a landfill site based on the exposure dose limits to support the establishment of technical bases for safety guide. We estimated the amount of NORM wastes for different activity levels of wastes containing U series, Th series, and {sup 40}K based on the exposure dose limits. The results of this study can be used as technical bases to support the establishment of a guide for the safe management of NORM waste disposal.

  4. Video x-ray progressive scanning: new technique for decreasing x-ray exposure without decreasing image quality during cardiac catheterization

    International Nuclear Information System (INIS)

    Holmes, D.R. Jr.; Bove, A.A.; Wondrow, M.A.; Gray, J.E.

    1986-01-01

    A newly developed video x-ray progressive scanning system improves image quality, decreases radiation exposure, and can be added to any pulsed fluoroscopic x-ray system using a video display without major system modifications. With use of progressive video scanning, the radiation entrance exposure rate measured with a vascular phantom was decreased by 32 to 53% in comparison with a conventional fluoroscopic x-ray system. In addition to this substantial decrease in radiation exposure, the quality of the image was improved because of less motion blur and artifact. Progressive video scanning has the potential for widespread application to all pulsed fluoroscopic x-ray systems. Use of this technique should make cardiac catheterization procedures and all other fluoroscopic procedures safer for the patient and the involved medical and paramedical staff

  5. Estimates of Ethanol Exposure in Children from Food not Labeled as Alcohol-Containing.

    Science.gov (United States)

    Gorgus, Eva; Hittinger, Maike; Schrenk, Dieter

    2016-09-01

    Ethanol is widely used in herbal medicines, e.g., for children. Furthermore, alcohol is a constituent of fermented food such as bread or yogurt and "non-fermented" food such as fruit juices. At the same time, exposure to very low levels of ethanol in children is discussed as possibly having adverse effects on psychomotoric functions. Here, we have analyzed alcohol levels in different food products from the German market. It was found that orange, apple and grape juice contain substantial amounts of ethanol (up to 0.77 g/L). Furthermore, certain packed bakery products such as burger rolls or sweet milk rolls contained more than 1.2 g ethanol/100 g. We designed a scenario for average ethanol exposure by a 6-year-old child. Consumption data for the "categories" bananas, bread and bakery products and apple juice were derived from US and German surveys. An average daily exposure of 10.3 mg ethanol/kg body weight (b.w.) was estimated. If a high (acute) consumption level was assumed for one of the "categories," exposure rose to 12.5-23.3 mg/kg b.w. This amount is almost 2-fold (average) or up to 4-fold (high) higher than the lowest exposure from herbal medicines (6 mg/kg b.w.) suggested to require warning hints for the use in children. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Population estimates of Australian children's exposure to food and beverage sponsorship of sports clubs.

    Science.gov (United States)

    Kelly, Bridget; Bauman, Adrian E; Baur, Louise A

    2014-07-01

    Sponsorship by manufacturers of unhealthy food can undermine the health promoting goals of sport. This study aimed to describe Australian children's exposure to organised sport, and compare time spent in specific sports with patterns of sponsorship of children's sport identified in previous studies. Cross-sectional survey on children's sport participation collected by proxy report using a random-digit-dialling survey of 3416 parents. Data from the 2009/10 Australian Sports Commission's Exercise, Recreation and Sport Survey were used to calculate weekly total person-time exposure to sports for Australian children, as a product of median weekly exposure (minutes) and the number of children participating. Exposures for children in NSW were calculated based on population distribution. Based on a previous survey of sport clubs in NSW, cumulative weekly exposure to food/beverage sponsorship at sports clubs was estimated for children living in NSW. 77.3% of Australian children aged 5-14 participated in organised sport. In NSW, weekly total person-time exposure for children was highest for outdoor soccer (91,200 children×median frequency of 2 sessions per week of 1h duration=182,400h/week). Considering rates of sponsorship at different sports, children would be exposed to food/beverage sponsorship to the greatest extent for rugby league and outdoor cricket. Children's high frequency of participation in organised sport and time spent engaging in these activities highlights the potentially huge reach of food/beverage sponsorship promotions. Policy interventions to limit children's exposure to this sponsorship should target those sports that have both the highest levels of children's participation and food/beverage sponsorship arrangements. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  7. Estimating Inorganic Arsenic Exposure from U.S. Rice and Total Water Intakes.

    Science.gov (United States)

    Mantha, Madhavi; Yeary, Edward; Trent, John; Creed, Patricia A; Kubachka, Kevin; Hanley, Traci; Shockey, Nohora; Heitkemper, Douglas; Caruso, Joseph; Xue, Jianping; Rice, Glenn; Wymer, Larry; Creed, John T

    2017-05-30

    Among nonoccupationally exposed U.S. residents, drinking water and diet are considered primary exposure pathways for inorganic arsenic (iAs). In drinking water, iAs is the primary form of arsenic (As), while dietary As speciation techniques are used to differentiate iAs from less toxic arsenicals in food matrices. Our goal was to estimate the distribution of iAs exposure rates from drinking water intakes and rice consumption in the U.S. population and ethnic- and age-based subpopulations. The distribution of iAs in drinking water was estimated by population, weighting the iAs concentrations for each drinking water utility in the Second Six-Year Review data set. To estimate the distribution of iAs concentrations in rice ingested by U.S. consumers, 54 grain-specific, production-weighted composites of rice obtained from U.S. mills were extracted and speciated using both a quantitative dilute nitric acid extraction and speciation (DNAS) and an in vitro gastrointestinal assay to provide an upper bound and bioaccessible estimates, respectively. Daily drinking water intake and rice consumption rate distributions were developed using data from the What We Eat in America (WWEIA) study. Using these data sets, the Stochastic Human Exposure and Dose Simulation (SHEDS) model estimated mean iAs exposures from drinking water and rice were 4.2 μg/day and 1.4 μg/day, respectively, for the entire U.S. population. The Tribal, Asian, and Pacific population exhibited the highest mean daily exposure of iAs from cooked rice (2.8 μg/day); the mean exposure rate for children between ages 1 and 2 years in this population is 0.104 μg/kg body weight (BW)/day. An average consumer drinking 1.5 L of water daily that contains between 2 and 3 ng iAs/mL is exposed to approximately the same amount of iAs as a mean Tribal, Asian, and Pacific consumer is exposed to from rice. https://doi.org/10.1289/EHP418. Among nonoccupationally exposed U.S. residents, drinking water and diet are considered

  8. FOODCHAIN: a Monte Carlo model to estimate individual exposure to airborne pollutants via the foodchain pathway

    International Nuclear Information System (INIS)

    Dixon, E.; Holton, G.A.

    1984-01-01

    Ingestion of contaminated food due to the airborne release of radionuclides or chemical pollutants is a particularly difficult human exposure pathway to quantify. There are a number of important physical and biological processes such as atmospheric deposition and plant uptake to consider. These processes are approximate by techniques encoded in the computer program TEREX. Once estimates of pollutant concentrations are made, the problem can be reduced to computing exposure from ingestion of the food. Some assessments do not account for where the contaminated food is eaten, while others limit consumption to meat and vegetables produced within the affected area. While those approaches lead to an upper bound of exposure, a more realistic assumption is that if locally produced food is not sufficient to meet the dietary needs of the local populace, then uncontaminated food will be imported. This is the approach taken by the computer model FOODCHAIN. Exposures via ingestion of six basic types of food are modeled: beef, milk, grains, leafy vegetables, exposed produce (edible parts are exposed to atmospheric deposition), and protected produce (edible parts are protected from atmospheric deposition). Intake requirements for these six foods are based on a standard diet. Using TEREX-produced site-specific crop production values and food contamination values, FOODCHAIN randomly samples pollutant concentrations in each of the six foodstuffs in an inerative manner. Consumption of a particular food is weighted by a factor proportional to the total production of that food within the area studied. The exposures due to consumption of each of the six foodstuffs are summed to produce the total exposure for each randomly calculated diet

  9. Importance of exposure model in estimating impacts when a water distribution system is contaminated

    International Nuclear Information System (INIS)

    Davis, M. J.; Janke, R.; Environmental Science Division; USEPA

    2008-01-01

    The quantity of a contaminant ingested by individuals using tap water drawn from a water distribution system during a contamination event depends on the concentration of the contaminant in the water and the volume of water ingested. If the concentration varies with time, the actual time of exposure affects the quantity ingested. The influence of the timing of exposure and of individual variability in the volume of water ingested on estimated impacts for a contamination event has received limited attention. We examine the significance of ingestion timing and variability in the volume of water ingested by using a number of models for ingestion timing and volume. Contaminant concentrations were obtained from simulations of an actual distribution system for cases involving contaminant injections lasting from 1 to 24 h. We find that assumptions about exposure can significantly influence estimated impacts, especially when injection durations are short and impact thresholds are high. The influence of ingestion timing and volume should be considered when assessing impacts for contamination events

  10. Estimated lead (Pb) exposures for a population of urban community gardeners.

    Science.gov (United States)

    Spliethoff, Henry M; Mitchell, Rebecca G; Shayler, Hannah; Marquez-Bravo, Lydia G; Russell-Anelli, Jonathan; Ferenz, Gretchen; McBride, Murray

    2016-08-01

    Urban community gardens provide affordable, locally grown, healthy foods and many other benefits. However, urban garden soils can contain lead (Pb) that may pose risks to human health. To help evaluate these risks, we measured Pb concentrations in soil, vegetables, and chicken eggs from New York City community gardens, and we asked gardeners about vegetable consumption and time spent in the garden. We then estimated Pb intakes deterministically and probabilistically for adult gardeners, children who spend time in the garden, and adult (non-gardener) household members. Most central tendency Pb intakes were below provisional total tolerable intake (PTTI) levels. High contact intakes generally exceeded PTTIs. Probabilistic estimates showed approximately 40 % of children and 10 % of gardeners exceeding PTTIs. Children's exposure came primarily from dust ingestion and exposure to higher Pb soil between beds. Gardeners' Pb intakes were comparable to children's (in µg/day) but were dominated by vegetable consumption. Adult household members ate less garden-grown produce than gardeners and had the lowest Pb intakes. Our results suggest that healthy gardening practices to reduce Pb exposure in urban community gardens should focus on encouraging cultivation of lower Pb vegetables (i.e., fruits) for adult gardeners and on covering higher Pb non-bed soils accessible to young children. However, the common practice of replacement of root-zone bed soil with clean soil (e.g., in raised beds) has many benefits and should also continue to be encouraged.

  11. Estimation of radiation exposure from lung cancer screening program with low-dose computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Yeon; Jun, Jae Kwan [Graduate School of Cancer Science and Policy, National Cancer Center, Seoul (Korea, Republic of)

    2016-12-15

    The National Lung Screening Trial (NLST) demonstrated that screening with Low-dose Computed Tomography (LDCT) screening reduced lung cancer mortality in a high-risk population. Recently, the United States Preventive Services Task Force (USPSTF) gave a B recommendation for annual LDCT screening for individuals at high-risk. With the promising results, Korea developed lung cancer screening guideline and is planning a pilot study for implementation of national lung cancer screening. With widespread adoption of lung cancer screening with LDCT, there are concerns about harms of screening, including high false-positive rates and radiation exposure. Over the 3 rounds of screening in the NLST, 96.4% of positive results were false-positives. Although the initial screening is performed at low dose, subsequent diagnostic examinations following positive results additively contribute to patient's lifetime exposure. As with implementing a large-scale screening program, there is a lack of established risk assessment about the effect of radiation exposure from long-term screening program. Thus, the purpose of this study was to estimate cumulative radiation exposure of annual LDCT lung cancer screening program over 20-year period.

  12. Estimating the distribution of lifetime cumulative radon exposures for California residents: a brief summary

    International Nuclear Information System (INIS)

    Liu, K.-S.; Chang, Y.-L.; Hayward, S.B.; Gadgil, A.J.; Nero, A.V.

    1992-01-01

    Data on residential radon concentrations in California, together with information on California residents' moving houses and time-activity patterns, have been used to estimate the distribution of lifetime cumulative exposures to 222 Rn. This distribution was constructed using Monte Carlo techniques to simulate the lifetime occupancy histories and associated radon exposures of 10,000 California residents. For standard male and female lifespans, the simulation sampled from transition probability matrices representing changes of residence within and between six regions of California, as well as into and out of the other United States, and then sampled from the appropriate regional (or national) distribution of indoor concentrations. The resulting distribution of lifetime cumulative exposures has a significantly narrower relative width than the distribution of California indoor concentrations, with only a small fraction (less than 0.2%) of the population having lifetime exposures equivalent to living their lifetimes in a single home with a radon concentration of 148 Bq.m -3 or more. (author)

  13. Comparison of temporal realistic telecommunication base station exposure with worst-case estimation in two countries

    International Nuclear Information System (INIS)

    Mahfouz, Z.; Verloock, L.; Joseph, W.; Tanghe, E.; Gati, A.; Wiart, J.; Lautru, D.; Hanna, V. F.; Martens, L.

    2013-01-01

    The influence of temporal daily exposure to global system for mobile communications (GSM) and universal mobile telecommunications systems and high speed down-link packet access (UMTS-HSDPA) is investigated using spectrum analyser measurements in two countries, France and Belgium. Temporal variations and traffic distributions are investigated. Three different methods to estimate maximal electric-field exposure are compared. The maximal realistic (99 %) and the maximal theoretical extrapolation factor used to extrapolate the measured broadcast control channel (BCCH) for GSM and the common pilot channel (CPICH) for UMTS are presented and compared for the first time in the two countries. Similar conclusions are found in the two countries for both urban and rural areas: worst-case exposure assessment overestimates realistic maximal exposure up to 5.7 dB for the considered example. In France, the values are the highest, because of the higher population density. The results for the maximal realistic extrapolation factor at the weekdays are similar to those from weekend days. (authors)

  14. Comparison of temporal realistic telecommunication base station exposure with worst-case estimation in two countries.

    Science.gov (United States)

    Mahfouz, Zaher; Verloock, Leen; Joseph, Wout; Tanghe, Emmeric; Gati, Azeddine; Wiart, Joe; Lautru, David; Hanna, Victor Fouad; Martens, Luc

    2013-12-01

    The influence of temporal daily exposure to global system for mobile communications (GSM) and universal mobile telecommunications systems and high speed downlink packet access (UMTS-HSDPA) is investigated using spectrum analyser measurements in two countries, France and Belgium. Temporal variations and traffic distributions are investigated. Three different methods to estimate maximal electric-field exposure are compared. The maximal realistic (99 %) and the maximal theoretical extrapolation factor used to extrapolate the measured broadcast control channel (BCCH) for GSM and the common pilot channel (CPICH) for UMTS are presented and compared for the first time in the two countries. Similar conclusions are found in the two countries for both urban and rural areas: worst-case exposure assessment overestimates realistic maximal exposure up to 5.7 dB for the considered example. In France, the values are the highest, because of the higher population density. The results for the maximal realistic extrapolation factor at the weekdays are similar to those from weekend days.

  15. Lifetime ultraviolet exposure estimates for selected population groups in south-east Queensland

    International Nuclear Information System (INIS)

    Parisi, A.V.; Meldrum, L.R.; Wong, J.C.F.; Fleming, R.A.; Aitken, J.

    1999-01-01

    The lifetime erythemal UV exposures received by selected population groups in south-east Queensland from birth up to an age of 55 years have been quantitatively estimated. A representative sample of teachers and other school workers received (64±22)x10 5 J m -2 to the neck compared with (4.1±1.4)x10 5 Jm -2 to the upper leg. A sample of indoor workers (bank officers, solicitors and psychologists) received approximately 2% less and a sample of outdoor workers (carpenters, tilers, electricians and labourers) received approximately 10% more to the neck than the school workers. These differences in erythemal UV exposures may influence the risk of non-melanoma skin cancer. (author)

  16. Estimating population exposure to power plant emissions using CALPUFF: a case study in Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.; Levy, J.I.; Hammitt, J.K.; Evans, J.S. [Harvard University, Boston, MA (USA). School of Public Health, Landmark Center

    2003-02-01

    Power plants are significant emitters of precursor gases of fine particulate matter. To evaluate the public health risk posed by power plants, it is necessary to evaluate population exposure to different pollutants. The concept of intake fraction (the fraction of a pollutant emitted that is eventually inhaled or ingested by a population) has been proposed to provide a simple summary measure of the relationship between emissions and exposure. Currently available intake fraction estimates from developing countries used models that look only at the near field impacts, which may not capture the full impact of a pollution source. This case study demonstrated how the intake fraction of power plant emissions in China can be calculated using a detailed long-range atmospheric dispersion model, CALPUFF. It was found that the intake fraction of primary fine particles is roughly on the order of 10{sup -5}, while the intake fractions of sulfur dioxide, sulfate and nitrate are on the order of 10{sup -6}. These estimates are an order of magnitude higher than the US estimates. The authors also tested how sensitive the results were to key assumptions within the model. The size distribution of primary particles has a large impact on the intake fraction for primary particles while the background ammonia concentration is an important factor influencing the intake fraction of nitrate. The background ozone concentration has a moderate impact on the intake fraction of sulfate and nitrate.

  17. Ultrasound simulator-assisted teaching of cardiac anatomy to preclinical anatomy students: A pilot randomized trial of a three-hour learning exposure.

    Science.gov (United States)

    Canty, David Jeffrey; Hayes, Jenny A; Story, David Andrew; Royse, Colin Forbes

    2015-01-01

    Ultrasound simulation allows students to virtually explore internal anatomy by producing accurate, moving, color, three-dimensional rendered slices from any angle or approach leaving the organs and their relationships intact without requirement for consumables. The aim was to determine the feasibility and efficacy of self-directed learning of cardiac anatomy with an ultrasound simulator compared to cadavers and plastic models. After a single cardiac anatomy lecture, fifty university anatomy students participated in a three-hour supervised self-directed learning exposure in groups of five, randomized to an ultrasound simulator or human cadaveric specimens and plastic models. Pre- and post-tests were conducted using pictorial and non-pictorial multiple-choice questions (MCQs). Simulator students completed a survey on their experience. Four simulator and seven cadaver group students did not attend after randomization. Simulator use in groups of five students was feasible and feedback from participants was very positive. Baseline test scores were similar (P = 0.9) between groups. After the learning intervention, there was no difference between groups in change in total test score (P = 0.37), whether they were pictorial (P = 0.6) or non-pictorial (P = 0.21). In both groups there was an increase in total test scores (simulator +19.8 ±12.4%% and cadaver: +16.4% ± 10.2, P human cadaveric prosections for learning cardiac anatomy. © 2014 American Association of Anatomists.

  18. Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

    Directory of Open Access Journals (Sweden)

    Robin B. Harris

    2012-03-01

    Full Text Available The Binational Arsenic Exposure Survey (BAsES was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001, urinary inorganic arsenic concentration (p < 0.001, and urinary sum of species (p < 0.001. Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

  19. Estimation of internal exposure dose from food after the Fukushima Daiichi Nuclear Power Station disaster

    International Nuclear Information System (INIS)

    Takizawa, Mari; Yoshizawa, Nobuaki; Kawai, Masaki; Miyatake, Hirokazu; Hirakawa, Sachiko; Murakami, Kana; Sato, Osamu; Takagi, Shunji; Suzuki, Gen

    2016-01-01

    In order to estimate the internal exposure dose from food due to the Fukushima Daiichi Nuclear Power Station accident, total diet study (TDS) has been carried out. TDS is a method for estimating how much of certain chemicals people intake in the normal diet. A wide range of food products are chosen as targets, and the increase or decrease of chemicals depending on processing or cooking is taken into account. This paper glanced at the transition of TDS survey results, and with a focus on the survey results of the market basket (MB) system, which is one of the TDS techniques, it examined a decrease in the committed effective dose per year of radioactive cesium. Although the values of internal exposure dose from food in Fukushima Prefecture and surrounding prefectures are even now in a relatively high tendency compared with those in the distant regions, the difference has been narrowing. According to the attenuation prediction of internal exposure dose in each region of Fukushima Prefecture, the values after 5 years from the accident will be lower than the measured value on the food in market that has been investigated during 1989 and 2005. In addition, the internal exposure dose that was the survey results based on MB system in September - October 2014 was 0.0007 to 0.0022 mSv/year. These values are very small at 1% or less of the upper limit dose of 1 mSv/year as the setting basis of current reference value in Japan. (A.O.)

  20. Tsunami exposure estimation with land-cover data: Oregon and the Cascadia subduction zone

    Science.gov (United States)

    Wood, N.

    2009-01-01

    A Cascadia subduction-zone earthquake has the potential to generate tsunami waves which would impact more than 1000 km of coastline on the west coast of the United States and Canada. Although the predictable extent of tsunami inundation is similar for low-lying land throughout the region, human use of tsunami-prone land varies, creating variations in community exposure and potential impacts. To better understand such variations, land-cover information derived from midresolution remotely-sensed imagery (e.g., 30-m-resolution Landsat Thematic Mapper imagery) was coupled with tsunami-hazard information to describe tsunami-prone land along the Oregon coast. Land-cover data suggest that 95% of the tsunami-prone land in Oregon is undeveloped and is primarily wetlands and unconsolidated shores. Based on Spearman rank correlation coefficients (rs), correlative relationships are strong and statistically significant (p < 0.05) between city-level estimates of the amount of land-cover pixels classified as developed (impervious cover greater than 20%) and the amount of various societal assets, including residential and employee populations, homes, businesses, and tax-parcel values. Community exposure to tsunami hazards, described here by the amount and relative percentage of developed land in tsunami-prone areas, varies considerably among the 26 communities of the study area, and these variations relate to city size. Correlative relationships are strong and significant (p < 0.05) for community exposure rankings based on land-cover data and those based on aggregated socioeconomic data. In the absence of socioeconomic data or community-based knowledge, the integration of hazards information and land-cover information derived from midresolution remotely-sensed imagery to estimate community exposure may be a useful first step in understanding variations in community vulnerability to regional hazards.

  1. Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Curl, Cynthia L; Beresford, Shirley A A; Fenske, Richard A; Fitzpatrick, Annette L; Lu, Chensheng; Nettleton, Jennifer A; Kaufman, Joel D

    2015-05-01

    Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce ("conventional consumers"), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p organic produce (p organic produce was associated with lower DAPs.

  2. Estimation of baseline lifetime risk of developed cancer related to radiation exposure in China

    International Nuclear Information System (INIS)

    Li Xiaoliang; Niu Haowei; Sun Quanfu; Ma Weidong

    2011-01-01

    Objective: To introduce the general international method for estimation of lifetime risk of developed cancer, and to estimate the lifetime risk baseline values of several kinds of cancers related to radiation exposures in China. Methods: The risk estimation was based on the data from Chinese Cancer Registry Annual Report (2010) and China Population and Employment Statistics Yearbook (2009), and made according to the method previously published by National Cancer Institute (NCI) in USA. Results: The lifetime risk of all cancer in China in 2007 was estimated to be 27.77%, that of lung cancer 5.96%, that of breast cancer for female 3.34%, that of all leukemia 0.14%, that of thyroid cancer 0.37%. The lifetime risks of all cancer were estimated to be 32.74% for males and 24.73% for females, and that was 36.47% for urban residents and 26.79% for rural people. Conclusions: The lifetime risk of all cancer for males in 2007 was about 1.25 times as much as that for females. The value of all cancer for urban residents was about 1.35 times as much as that for rural residents. The lifetime risk of developed cancers in 2007 in China is lower than that in the developed countries,such as Japan. (authors)

  3. Low-dose computed tomography scans with automatic exposure control for patients of different ages undergoing cardiac PET/CT and SPECT/CT.

    Science.gov (United States)

    Yang, Ching-Ching; Yang, Bang-Hung; Tu, Chun-Yuan; Wu, Tung-Hsin; Liu, Shu-Hsin

    2017-06-01

    This study aimed to evaluate the efficacy of automatic exposure control (AEC) in order to optimize low-dose computed tomography (CT) protocols for patients of different ages undergoing cardiac PET/CT and single-photon emission computed tomography/computed tomography (SPECT/CT). One PET/CT and one SPECT/CT were used to acquire CT images for four anthropomorphic phantoms representative of 1-year-old, 5-year-old and 10-year-old children and an adult. For the hybrid systems investigated in this study, the radiation dose and image quality of cardiac CT scans performed with AEC activated depend mainly on the selection of a predefined image quality index. Multiple linear regression methods were used to analyse image data from anthropomorphic phantom studies to investigate the effects of body size and predefined image quality index on CT radiation dose in cardiac PET/CT and SPECT/CT scans. The regression relationships have a coefficient of determination larger than 0.9, indicating a good fit to the data. According to the regression models, low-dose protocols using the AEC technique were optimized for patients of different ages. In comparison with the standard protocol with AEC activated for adult cardiac examinations used in our clinical routine practice, the optimized paediatric protocols in PET/CT allow 32.2, 63.7 and 79.2% CT dose reductions for anthropomorphic phantoms simulating 10-year-old, 5-year-old and 1-year-old children, respectively. The corresponding results for cardiac SPECT/CT are 8.4, 51.5 and 72.7%. AEC is a practical way to reduce CT radiation dose in cardiac PET/CT and SPECT/CT, but the AEC settings should be determined properly for optimal effect. Our results show that AEC does not eliminate the need for paediatric protocols and CT examinations using the AEC technique should be optimized for paediatric patients to reduce the radiation dose as low as reasonably achievable.

  4. Estimated values of the genetic and somatic radiation exposure of the Bulgarian population in 1976

    International Nuclear Information System (INIS)

    Poppitz, R.; Dobrev, D.

    1979-01-01

    The genetically and leukemia-significant doses (GSD and LSD) were calculated from the average gonad and bone marrow doses caused by the most frequently applied radiopharmaceuticals in Bulgaria in 1976. Because of the lack of information about the age groups of the patients examined assumptions have been made which led to estimated values of 0.97 mrad for GSD and 2.0 mrad for LSD which must be considered as the upper limit of the real GSD and LSD. The influence of the different radiopharmaceuticals on the average radiation exposure of the population is discussed. (author)

  5. Estimation of health effects due to elevated radiation exposure levels in structures

    International Nuclear Information System (INIS)

    Marks, S.; Cross, F.T.; Denham, D.H.; Kennedy, W.E. Jr.

    1985-02-01

    Uranium mill tailings were used as landfill for many years in the United States before the health risk associated with such use was recognized. Occupants of buildings erected on or adjacent to contaminated landfills may experience radiation exposures sufficient to warrant remedial action. Estimates of the cost-effectiveness of the remedial measures may be provided using a combination of occupancy data, appropriate risk coefficients and projected costs. This effort is in support of decisions by the US Department of Energy (DOE) to conduct remedial action at such locations. The methods used in this project, with examples of their application, will be presented in this paper

  6. Biological dose estimation of partial body exposures in cervix cancer patients

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Nasazzi, Nora B.; Taja, Maria R.; Roth, B.; Sardi, M.; Menendez, P.

    2000-01-01

    At present, unstable chromosome aberrations analysis in peripheral blood lymphocytes is the most sensitive method to provide a biological estimation of the dose in accidental radiation over exposures. The assessment of the dose is particularly reliable in cases of acute, uniform, whole-body exposures or after irradiation of large parts of the body. However, the scenarios of most radiation accidents result in partial-body exposures or non-uniform dose distribution, leading to a differential exposure of lymphocytes in the body. Inhomogeneity produces a yield of dicentrics, which does not conform to a Poisson distribution, but is generally over dispersed. This arises because those lymphocytes in tissues outside the radiation field will not be damaged. Most of the lymphocytes (80 %) belong to the 'redistributional pool' (lymphatic tissues and other organs) and made recirculate into peripheral blood producing a mixed irradiated and unirradiated population of lymphocytes. So-called over dispersion, with a variance greater than the mean, can be taken as an indication of non-uniform exposure. The main factors operating in vivo partial-body irradiation may be the location and size of the irradiation field and, at high doses, various cellular reactions such as reduced blast transformation, mitotic delay or interphase death may contribute. For partial-body exposures, mathematical-statistical analysis of chromosome aberration data can be performed to derive a dose estimate for the irradiated fraction of the body, been more realistic than to quote a mean equivalent uniform whole body dose. The 'Contaminated Poisson' method of Dolphin or the Qdr method of Sasaki, both based on similar principles, can achieve this. Contaminated Poisson considers the over dispersed distribution of dicentrics among all the cells scored. The observed distribution is considered to be the sum of a Poisson distribution, which represents the irradiated fraction of the body, and the remaining unexposed

  7. A single exposure to acrolein causes arrhythmogenesis, cardiac electrical dysfunction and decreased heart rate variability in hypertensive rats

    Science.gov (United States)

    Epidemiological studies demonstrate an association between cardiovascular morbidity, arrhythmias, and exposure to air toxicants such as acrolein. We hypothesized that a single exposure to acrolein would increase arrhythmias and cause changes in the electrocardiogram (ECG) of hype...

  8. Estimation of Radiofrequency Power Leakage from Microwave Ovens for Dosimetric Assessment at Nonionizing Radiation Exposure Levels

    Directory of Open Access Journals (Sweden)

    Peio Lopez-Iturri

    2015-01-01

    Full Text Available The electromagnetic field leakage levels of nonionizing radiation from a microwave oven have been estimated within a complex indoor scenario. By employing a hybrid simulation technique, based on coupling full wave simulation with an in-house developed deterministic 3D ray launching code, estimations of the observed electric field values can be obtained for the complete indoor scenario. The microwave oven can be modeled as a time- and frequency-dependent radiating source, in which leakage, basically from the microwave oven door, is propagated along the complete indoor scenario interacting with all of the elements present in it. This method can be of aid in order to assess the impact of such devices on expected exposure levels, allowing adequate minimization strategies such as optimal location to be applied.

  9. A randomly-controlled study on the cardiac function at the early stage of return to the plains after short-term exposure to high altitude.

    Directory of Open Access Journals (Sweden)

    Qiquan Zhou

    Full Text Available High altitude acclimatization and adaptation mechanisms have been well clarified, however, high altitude de-adaptation mechanism remains unclear. In this study, we conducted a controlled study on cardiac functions in 96 healthy young male who rapidly entered the high altitude (3700 m and returned to the plains (1500 m after 50 days. Ninety eight healthy male who remained at low altitude were recruited as control group. The mean pulmonary arterial pressure (mPAP, left ventricular ejection fraction (LVEF, left ventricular fraction shortening (LVFS, cardiac function index (Tei index were tested. Levels of serum creatine kinase isoform MB (CK-MB, lactate dehydrogenase isoenzyme-1 (LDH-1, endothelin-1 (ET-1, nitrogen oxide (NO, serum hypoxia-inducible factor-1α (HIF-1α, 8-iso-prostaglandin F(2α (8-iso PGF(2α, superoxide dismutase (SOD and malonaldehyde (MDA were measured at an altitude of 3700 m and 1500 m respectively. The results showed that after short-term exposure to high altitude mPAP and Tei index increased significantly, while LVEF and LVFS decreased significantly. These changes were positively correlated with altitude. On the 15(th day after the subjects returned to low altitude, mPAP, LVEF and LVFS levels returned to the same level as those of the control subjects, but the Tei index in the returned subjects was still significantly higher than that in the control subjects (P<0.01. We also found that changes in Tei index was positively correlated with mPAP, ET-1, HIF-1α and 8-iso PGF(2α levels, and negatively correlated with the level of NO, LVEF, LVFS, CK-MB and LDH-1. These findings suggest that cardiac function de-adapts when returning to the plains after short-term exposure to high altitude and the function recovery takes a relatively long time.

  10. Estimating Effective Dose of Radiation From Pediatric Cardiac CT Angiography Using a 64-MDCT Scanner: New Conversion Factors Relating Dose-Length Product to Effective Dose.

    Science.gov (United States)

    Trattner, Sigal; Chelliah, Anjali; Prinsen, Peter; Ruzal-Shapiro, Carrie B; Xu, Yanping; Jambawalikar, Sachin; Amurao, Maxwell; Einstein, Andrew J

    2017-03-01

    The purpose of this study is to determine the conversion factors that enable accurate estimation of the effective dose (ED) used for cardiac 64-MDCT angiography performed for children. Anthropomorphic phantoms representative of 1- and 10-year-old children, with 50 metal oxide semiconductor field-effect transistor dosimeters placed in organs, underwent scanning performed using a 64-MDCT scanner with different routine clinical cardiac scan modes and x-ray tube potentials. Organ doses were used to calculate the ED on the basis of weighting factors published in 1991 in International Commission on Radiological Protection (ICRP) publication 60 and in 2007 in ICRP publication 103. The EDs and the scanner-reported dose-length products were used to determine conversion factors for each scan mode. The effect of infant heart rate on the ED and the conversion factors was also assessed. The mean conversion factors calculated using the current definition of ED that appeared in ICRP publication 103 were as follows: 0.099 mSv · mGy -1 · cm -1 , for the 1-year-old phantom, and 0.049 mSv · mGy -1 · cm -1 , for the 10-year-old phantom. These conversion factors were a mean of 37% higher than the corresponding conversion factors calculated using the older definition of ED that appeared in ICRP publication 60. Varying the heart rate did not influence the ED or the conversion factors. Conversion factors determined using the definition of ED in ICRP publication 103 and cardiac, rather than chest, scan coverage suggest that the radiation doses that children receive from cardiac CT performed using a contemporary 64-MDCT scanner are higher than the radiation doses previously reported when older chest conversion factors were used. Additional up-to-date pediatric cardiac CT conversion factors are required for use with other contemporary CT scanners and patients of different age ranges.

  11. Estimated Risk of Developing Selected DSM-IV Disorders among 5-Year-Old Children with Prenatal Cocaine Exposure

    Science.gov (United States)

    Morrow, Connie E.; Accornero, Veronica H.; Xue, Lihua; Manjunath, Sudha; Culbertson, Jan L.; Anthony, James C.; Bandstra, Emmalee S.

    2009-01-01

    We estimated childhood risk of developing selected DSM-IV Disorders, including Attention-Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), and Separation Anxiety Disorder (SAD), in children with prenatal cocaine exposure (PCE). Children were enrolled prospectively at birth (n = 476) with prenatal drug exposures documented…

  12. Estimation of quantitative levels of diesel exhaust exposure and the health impact in the contemporary Australian mining industry

    NARCIS (Netherlands)

    Peters, Susan; de Klerk, Nicholas; Reid, Alison; Fritschi, Lin; Musk, Aw Bill; Vermeulen, Roel

    2017-01-01

    OBJECTIVES: To estimate quantitative levels of exposure to diesel exhaust expressed by elemental carbon (EC) in the contemporary mining industry and to describe the excess risk of lung cancer that may result from those levels. METHODS: EC exposure has been monitored in Western Australian miners

  13. Radiation exposure estimates on production and utilization of recycled items using dismantling waste

    International Nuclear Information System (INIS)

    Nakamura, Hisashi; Nakashima, Mikio

    2002-03-01

    Radiation exposure was estimated on production and utilization of recycled items using dismantling wastes by assuming that their usage are restricted to nuclear facilities. The radiation exposure attributed to production of a steel-plate cast iron waste container, a receptacle for slag, and a drum reinforcement was calculated to be in the range of several μSv to several tens of μSv even in recycling contaminated metal waste of which radioactivity concentration of Co-60 is higher than the clearance level by a factor of two figures. It is also elucidated that casting of a multiple casting waste package meets the standards of dose equivalent rate for the transport of a radioactive package and the weight of the package will be able to kept around 20 tons for the convenience of the handling, in case of disposal of metal waste less than 37 MBq/g with the steel-plate cast iron waste container. As the results, from the radiological exposure's point of view, it should be possible to use slightly contaminated metal for recycled items in waste management. (author)

  14. Dietary PCDD/PCDF exposure estimates for the U.S. population

    Energy Technology Data Exchange (ETDEWEB)

    South, P.; S. Kathleen Egan; Troxell, T.; P. Michael Bolger [U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park (United States)

    2004-09-15

    Dioxin-like compounds (DLCs) are a group of environmental contaminants whose primary route of human exposure occurs via the consumption of fatty foods of animal origin. Since the mid-1990s, the U.S. Food and Drug Administration (FDA) has tested specific foods with the goal of describing and reducing DLC exposure. In 1999, FDA's dioxin monitoring program began analyzing foods collected under its Total Diet Study (TDS). Conducted annually since 1961, the TDS is FDA's ongoing market basket survey designed to monitor the U.S. food supply for levels of toxic chemical contaminants (pesticide residues, industrial chemicals and toxic elements) and nutritional elements. This paper reports on dietary exposure estimates for DLCs, specifically polychlorinated dibenzo-pdioxin (PCDD) and polychlorinated dibenzofuran (PCDF), calculated from results of PCDD/PCDF analyses of TDS samples from 2001 and 2002 and food consumption data collected in USDA's 1994-96, 1998 Continuing Survey of Food Intakes by Individuals (CSFII).

  15. Cytogenetic biodosimetry to estimate radiation doses received in accidental radiological exposures

    International Nuclear Information System (INIS)

    AIsbeih, Ghazi

    2014-01-01

    The tremendous applications of nuclear technologies in various aspects of life increase the probability of over exposure due to involuntary or premeditated nuclear accidents. National radiation-protection preparedness requires adequate estimate of dose received for efficient medical assistance of victims. Cytogenetic biodosimetry is an ISO and IAEA standardized biotechnology technique. We have established a reference biological dosimetry laboratory to boost the nation's ability to respond to sporadic and mass radiation casualty incidents and to assess the magnitude of radiation overexposure. Accurate calculation of radiation doses received will result in evidence based treatment decisions and better management of valuable emergency resources. It will also contribute to the 'National Radiation Protection Program' by playing a role in nuclear emergency plans. The cytogenetic method is standardized and scalable. In addition to diagnosis of over exposure, it provides triage capability for rapid stratification of patients who need more specialized medical care. It can also detect false positives and false negatives exposure particularly in cases of legal allegations

  16. Hospital and clinic survey estimates of medical x-ray exposures in Hiroshima and Nagasaki, (1)

    International Nuclear Information System (INIS)

    Sawada, Shozo; Land, C.E.; Otake, Masanori; Russell, W.J.; Takeshita, Kenji.

    1980-11-01

    All large hospitals and 40% of the small hospitals and clinics in Hiroshima and Nagasaki cities were surveyed for the X-ray examinations they performed during a 2-week period in 1974. The frequency and type of X-ray examinations received by members of the RERF Adult Health Study (AHS) and the RERF Life Span Study (LSS) extended, excluding AHS (Non-AHS), were compared with the general population in each city. Radiologic exposures of patients at hospitals and clinics were most frequent among the general populations. The number of patients, examinations, and exposures per caput per year in each population were estimated. Since the age distribution differed among the three populations, comparisons were made only after correcting for age. On a per caput per year basis exposure frequency was relatively high in the AHS and low in the general populations, a reflection of the greater number of patients in the AHS than in the general populations. Non-AHS males in Nagasaki had a higher X-ray examination rate than did the AHS subjects. The others in the Non-AHS did not differ appreciably from the general populations. There was no difference among these groups according to body sites examined. (author)

  17. Estimating internal exposure risks by the relative risk and the National Institute of Health risk models

    International Nuclear Information System (INIS)

    Mehta, S.K.; Sarangapani, R.

    1995-01-01

    This paper presents tabulations of risk (R) and person-years of life lost (PYLL) for acute exposures of individual organs at ages 20 and 40 yrs for the Indian and Japanese populations to illustrate the effect of age at exposure in the two models. Results are also presented for the organ wise nominal probability coefficients (NPC) and PYLL for individual organs for the age distributed Indian population by the two models. The results presented show that for all organs the estimates of PYLL and NPC for the Indian population are lower than those for the Japanese population by both models except for oesophagus, breast and ovary by the relative risk (RR) model, where the opposite trend is observed. The results also show that the Indian all-cancer values of NPC averaged over the two models is 2.9 x 10 -2 Sv -1 , significantly lower than the world average value of 5x10 -2 Sv -1 estimated by the ICRP. (author). 9 refs., 2 figs., 2 tabs

  18. Estimated risk from exposure to radon decay products in US homes

    International Nuclear Information System (INIS)

    Nero, A.V. Jr.

    1986-05-01

    Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in US homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average 222 Rn concentrations averaging 55 Bq m -3 and having 2% of homes exceeding 300 Bq m -3 . Application of the results of occupational epidemiological studies, either directly or using recent advances in lung dosimetry, to indoor exposures suggests that the average indoor concentration entails a lifetime risk of lung cancer of 0.3% or about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m -3 or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m -3 correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. The potential for such average and high-level risks in ordinary homes forces development of a new perspective on environmental exposures

  19. Recent advances in the estimation of genetic risks of exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    2002-01-01

    This paper reviews the major advances that have occurred during the last few years in the estimation of genetic risks of exposure of human populations to ionizing radiation. Among these are: (i) an upward revision of the estimates of the baseline frequencies of Mendelian diseases (from 1.25% to 2.4%); (ii) the conceptual change to the use of a doubling dose based on human data on spontaneous mutation rates and mouse data on induced mutation rates (from the one based entirely on mouse data on spontaneous and induced mutation rates, which was the case thus far); (iii) the fuller development of the concept of mutation component (MC) and its application to predict the responsiveness of Mendelian and chronic multi factorial diseases to induced mutations; (iv) the introduction of the concept that the major adverse effects of radiation exposure of human germ cells are likely to be manifest as multi-system developmental abnormalities and (v) the introduction of concept of potential recoverability correction factor (PRCF) to bridge the gap between induced mutations studied in mice and the risk of genetic disease in humans are reviewed

  20. The influence of study species selection on estimates of pesticide exposure in free-ranging birds

    Science.gov (United States)

    Borges, Shannon L.; Vyas, Nimish B.; Christman, Mary C.

    2014-01-01

    Field studies of pesticide effects on birds often utilize indicator species with the purpose 16 of extrapolating to other avian taxa. Little guidance exists for choosing indicator species to 17 monitor the presence and/or effects of contaminants that are labile in the environment or body, 18 but are acutely toxic, such as anticholinesterase (anti-ChE) insecticides. Use of an indicator 19 species that does not represent maximum exposure and/or effects could lead to inaccurate risk 20 estimates. Our objective was to test the relevance of a priori selection of indicator species for a 21 study on pesticide exposure to birds inhabiting fruit orchards. We used total plasma 22 cholinesterase (ChE) activity and ChE reactivation to describe the variability in anti-ChE exposure among avian species in two conventionally managed fruit orchards. Of seven 24 species included in statistical analyses, the less common species, chipping sparrow (Spizella 25 passerina), showed the greatest percentage of exposed individuals and the greatest ChE 26 depression, whereas the two most common species, American robins (Turdus migratorius) and 27 grey catbirds (Dumatella carolinensis), did not show significant exposure. Due to their lower 28 abundance, chipping sparrows would have been an unlikely choice for study. Our results show 29 that selection of indicator species using traditionally accepted criteria such as abundance and 30 ease of collection may not identify species that are at greatest risk. Our efforts also demonstrate 31 the usefulness of conducting multiple-species pilot studies prior to initiating detailed studies on 32 pesticide effects. A study such as ours can help focus research and resources on study species 33 that are most appropriate.

  1. Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices: The Multi-Ethnic Study of Atherosclerosis (MESA)

    Science.gov (United States)

    Beresford, Shirley A.A.; Fenske, Richard A.; Fitzpatrick, Annette L.; Lu, Chensheng; Nettleton, Jennifer A.; Kaufman, Joel D.

    2015-01-01

    Background Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. Objectives We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Methods Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce (“conventional consumers”), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Results Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p Fenske RA, Fitzpatrick AL, Lu C, Nettleton JA, Kaufman JD. 2015. Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA). Environ Health Perspect 123:475–483; http://dx.doi.org/10.1289/ehp.1408197 PMID:25650532

  2. Estimated dietary dioxin exposure and breast cancer risk among women from the French E3N prospective cohort.

    Science.gov (United States)

    Danjou, Aurélie M N; Fervers, Béatrice; Boutron-Ruault, Marie-Christine; Philip, Thierry; Clavel-Chapelon, Françoise; Dossus, Laure

    2015-03-17

    Dioxins are environmental and persistent pollutants mostly emitted from combustion facilities (e.g. waste incinerators, metal and cement industries). Known to be endocrine disrupting chemicals, dioxins are suspected to increase breast cancer (BC) risk. Although diet is considered the primary source of dioxin exposure, no previous study has been published on dietary dioxin exposure in relation to BC risk. We aimed to assess dietary dioxin exposure among women from the E3N cohort and estimate BC risk associated with this exposure. The study included 63,830 women from the E3N cohort who completed a diet history questionnaire (DHQ) in 1993 and were followed until 2008. Dietary dioxin exposure was estimated by combining consumption data from the E3N DHQ and food dioxin contamination data from a French national monitoring program. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox models adjusted for BC risk factors. Mean dietary dioxin exposure was estimated at 1.3 ± 0.4 pg/kg body weight (BW)/day. A 0.4 pg/kg BW/d increase in dioxin intake was not associated with overall BC risk (HR = 1.00; 95% CI: 0.96, 1.05). A significant decrease in risk of estrogen receptor negative (ER-)/progesterone receptor negative (PR-) tumors was observed among post-menopausal women in the upper quartile of estimated dioxin intake (HR for Q4 vs. Q1: 0.65; 95% CI: 0.45, 0.96; P for trend across quartiles = 0.0463). Overall, no association between estimated dietary dioxin exposure and BC risk was found among E3N women. Further studies should include both dietary and environmental exposures to determine whether low-dose dioxin exposure is associated with BC risk.

  3. Gamma exposure rate estimation in irradiation facilities of nuclear research reactors

    International Nuclear Information System (INIS)

    Daoud, Adrian

    2009-01-01

    There are experimental situations in the nuclear field, in which dose estimations due to energy-dependent radiation fields are required. Nuclear research reactors provide such fields under normal operation or due to radioactive disintegration of fission products and structural materials activation. In such situations, it is necessary to know the exposure rate of gamma radiation the different materials under experimentation are subject to. Detectors of delayed reading are usually used for this purpose. Direct evaluation methods using portable monitors are not always possible, because in some facilities the entrance with such devices is often impracticable and also unsafe. Besides, these devices only provide information of the place where the measurement was performed, but not of temporal and spatial fluctuations the radiation fields could have. In this work a direct evaluation method was developed for the 'in-situ' gamma exposure rate for the irradiation facilities of the RA-1 reactor. This method is also applicable in any similar installation, and may be complemented by delayed evaluations without problem. On the other hand, it is well known that the residual effect of radiation modifies some properties of the organic materials used in reactors, such as density, colour, viscosity, oxidation level, among others. In such cases, a correct dosimetric evaluation enables in service estimation of material duration with preserved properties. This evaluation is for instance useful when applied to lubricating oils for the primary circuit pumps in nuclear power plants, thus minimizing waste generation. In this work the necessary elements required to estimate in-situ time and space integrated dose are also established for a gamma irradiated sample in an irradiation channel of a nuclear facility with zero neutron flux. (author)

  4. Estimated yield of double-strand breaks from internal exposure to tritium

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing [Health Canada, Radiation Protection Bureau, Ottawa, ON (Canada)

    2012-08-15

    Internal exposure to tritium may result in DNA lesions. Of those, DNA double-strand breaks (DSBs) are believed to be important. However, experimental and computational data of DSBs induction by tritium are very limited. In this study, microdosimetric characteristics of uniformly distributed tritium were determined in dimensions of critical significance in DNA DSBs. Those characteristics were used to identify other particles comparable to tritium in terms of microscopic energy deposition. The yield of DSBs could be strongly dependent on biological systems and cellular environments. After reviewing theoretically predicted and experimentally determined DSB yields available in the literature for low-energy electrons and high-energy protons of comparable microdosimetric characteristics to tritium in the dimensions relevant to DSBs, it is estimated that the average DSB yields of 2.7 x 10{sup -11}, 0.93 x 10{sup -11}, 2.4 x 10{sup -11} and 1.6 x 10{sup -11} DSBs Gy{sup -1} Da{sup -1} could be reasonable estimates for tritium in plasmid DNAs, yeast cells, Chinese hamster V79 cells and human fibroblasts, respectively. If a biological system is not specified, the DSB yield from tritium exposure can be estimated as (2.3 ± 0.7) x 10{sup -11} DSBs Gy{sup -1} Da{sup -1}, which is a simple average over experimentally determined yields of DSBs for low-energy electrons in various biological systems without considerations of variations caused by different techniques used and obvious differences among different biological systems where the DSB yield was measured. (orig.)

  5. Estimated yield of double-strand breaks from internal exposure to tritium.

    Science.gov (United States)

    Chen, Jing

    2012-08-01

    Internal exposure to tritium may result in DNA lesions. Of those, DNA double-strand breaks (DSBs) are believed to be important. However, experimental and computational data of DSBs induction by tritium are very limited. In this study, microdosimetric characteristics of uniformly distributed tritium were determined in dimensions of critical significance in DNA DSBs. Those characteristics were used to identify other particles comparable to tritium in terms of microscopic energy deposition. The yield of DSBs could be strongly dependent on biological systems and cellular environments. After reviewing theoretically predicted and experimentally determined DSB yields available in the literature for low-energy electrons and high-energy protons of comparable microdosimetric characteristics to tritium in the dimensions relevant to DSBs, it is estimated that the average DSB yields of 2.7 × 10(-11), 0.93 × 10(-11), 2.4 × 10(-11) and 1.6 × 10(-11) DSBs Gy(-1) Da(-1) could be reasonable estimates for tritium in plasmid DNAs, yeast cells, Chinese hamster V79 cells and human fibroblasts, respectively. If a biological system is not specified, the DSB yield from tritium exposure can be estimated as (2.3 ± 0.7) × 10(-11) DSBs Gy(-1) Da(-1), which is a simple average over experimentally determined yields of DSBs for low-energy electrons in various biological systems without considerations of variations caused by different techniques used and obvious differences among different biological systems where the DSB yield was measured.

  6. Energy expenditure estimation in beta-blocker-medicated cardiac patients by combining heart rate and body movement data

    NARCIS (Netherlands)

    Kraal, Jos J.; Sartor, Francesco; Papini, Gabriele; Stut, Wim; Peek, Niels; Kemps, Hareld Mc; Bonomi, Alberto G.

    2016-01-01

    Accurate assessment of energy expenditure provides an opportunity to monitor physical activity during cardiac rehabilitation. However, the available assessment methods, based on the combination of heart rate (HR) and body movement data, are not applicable for patients using beta-blocker medication.

  7. Cardiac autonomic regulation during exposure to auditory stimulation with classical baroque or heavy metal music of different intensities.

    Science.gov (United States)

    Amaral, Joice A T; Nogueira, Marcela L; Roque, Adriano L; Guida, Heraldo L; De Abreu, Luiz Carlos; Raimundo, Rodrigo Daminello; Vanderlei, Luiz Carlos M; Ribeiro, Vivian L; Ferreira, Celso; Valenti, Vitor E

    2014-03-01

    The effects of chronic music auditory stimulation on the cardiovascular system have been investigated in the literature. However, data regarding the acute effects of different styles of music on cardiac autonomic regulation are lacking. The literature has indicated that auditory stimulation with white noise above 50 dB induces cardiac responses. We aimed to evaluate the acute effects of classical baroque and heavy metal music of different intensities on cardiac autonomic regulation. The study was performed in 16 healthy men aged 18-25 years. All procedures were performed in the same soundproof room. We analyzed heart rate variability (HRV) in time (standard deviation of normal-to-normal R-R intervals [SDNN], root-mean square of differences [RMSSD] and percentage of adjacent NN intervals with a difference of duration greater than 50 ms [pNN50]) and frequency (low frequency [LF], high frequency [HF] and LF/HF ratio) domains. HRV was recorded at rest for 10 minutes. Subsequently, the volunteers were exposed to one of the two musical styles (classical baroque or heavy metal music) for five minutes through an earphone, followed by a five-minute period of rest, and then they were exposed to the other style for another five minutes. The subjects were exposed to three equivalent sound levels (60-70dB, 70-80dB and 80-90dB). The sequence of songs was randomized for each individual. Auditory stimulation with heavy metal music did not influence HRV indices in the time and frequency domains in the three equivalent sound level ranges. The same was observed with classical baroque musical auditory stimulation with the three equivalent sound level ranges. Musical auditory stimulation of different intensities did not influence cardiac autonomic regulation in men.

  8. Estimated population exposure from nuclear power production and other radiation sources

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1976-01-01

    Estimates are given of the total radiation dose from all forms of ionizing radiation resulting from nuclear power reduction. A power consumption of 1kW per head of population, derived entirely from nuclear energy, would increase the average radiation exposure of the whole population from 100mrem per year from natural sources (plus about 40mrem per year from medical procedures and other artificial causes) by about 6mrem per year. The genetically signifificant component of this increase would be about 4mrem per year. Available estimates of harm from radiation would indicate that this would give a risk per year per million of population of about 1 fatal induced malignancy, about the same number of malignancies fully treatable by operation, and, after many generations, about the same number of inherited defects, of greater or less severity, per year. Accidental injuries, particularly in constructional and mining work, would cause an estimated 1 fatality and 50 other accidents annually. Indications are given of the number of fatalities and accidents involved in equal power production by alternative methods, and of the value and limitations of such numerical comparisons in reaching decisions on the development of future power programmes

  9. Preliminary results of an attempt to predict over apron occupational exposure of cardiologists from cardiac fluoroscopy procedures based on DAP (dose area product) values.

    Science.gov (United States)

    Toossi, Mohammad Taghi Bahreyni; Mehrpouyan, Mohammad; Nademi, Hossein; Fardid, Reza

    2015-03-01

    This study is an effort to propose a mathematical relation between the occupational exposure measured by a dosimeter worn on a lead apron in the chest region of a cardiologist and the dose area product (DAP) recorded by a meter attached to the X-ray tube. We aimed to determine factors by which DAP values attributed to patient exposure could be converted to the over-apron entrance surface air kerma incurred by cardiologists during an angiographic procedure. A Rando phantom representing a patient was exposed by an X-ray tube from 77 pre-defined directions. DAP value for each exposure angle was recorded. Cardiologist exposure was measured by a Radcal ionization chamber 10X5-180 positioned on a second phantom representing the physician. The exposure conversion factor was determined as the quotient of over apron exposure by DAP value. To verify the validity of this method, the over-apron exposure of a cardiologist was measured using the ionization chamber while performing coronary angiography procedures on 45 patients weighing on average 75 ± 5 kg. DAP values for the corresponding procedures were also obtained. Conversion factors obtained from phantom exposure were applied to the patient DAP values to calculate physician exposure. Mathematical analysis of our results leads us to conclude that a linear relationship exists between two sets of data: (a) cardiologist exposure measured directly by Radcal & DAP values recorded by the X-ray machine system (R (2) = 0.88), (b) specialist measured and estimated exposure derived from DAP values (R (2) = 0.91). The results demonstrate that cardiologist occupational exposure can be derived from patient data accurately.

  10. Development of the town data base: Estimates of exposure rates and times of fallout arrival near the Nevada Test Site

    International Nuclear Information System (INIS)

    Thompson, C.B.; McArthur, R.D.; Hutchinson, S.W.

    1994-09-01

    As part of the U.S. Department of Energy's Off-Site Radiation Exposure Review Project, the time of fallout arrival and the H+12 exposure rate were estimated for populated locations in Arizona, California, Nevada, and Utah that were affected by fallout from one or more nuclear tests at the Nevada Test Site. Estimates of exposure rate were derived from measured values recorded before and after each test by fallout monitors in the field. The estimate for a given location was obtained by retrieving from a data base all measurements made in the vicinity, decay-correcting them to H+12, and calculating an average. Estimates were also derived from maps produced after most events that show isopleths of exposure rate and time of fallout arrival. Both sets of isopleths on these maps were digitized, and kriging was used to interpolate values at the nodes of a 10-km grid covering the pattern. The values at any location within the grid were then estimated from the values at the surrounding grid nodes. Estimates of dispersion (standard deviation) were also calculated. The Town Data Base contains the estimates for all combinations of location and nuclear event for which the estimated mean H+12 exposure rate was greater than three times background. A listing of the data base is included as an appendix. The information was used by other project task groups to estimate the radiation dose that off-site populations and individuals may have received as a result of exposure to fallout from Nevada nuclear tests

  11. Simultaneous exposure to concentrated ambient particles and acrolein causes cardiac effects mediated by parasympathetic modulation in mice

    Science.gov (United States)

    This study shows that exposure to CAPs and acrolein causes an increase in HRV that is mediated by the parasympathetic nervous system. Numerous studies show that short-term air pollution exposure modulates heart rate variability (HRV), which is an indicator of autonomic influence...

  12. Estimation of effectiveness of automatic exposure control in computed tomograph scanner

    International Nuclear Information System (INIS)

    Akhilesh, Philomina; Sharma, S.D.; Datta, D.; Kulkarni, Arti

    2018-01-01

    With the advent of multiple detector array technology, the use of Computed Tomography (CT) scanning has increase tremendously. Computed Tomography examinations deliver relatively high radiation dose to patients in comparison with conventional radiography. It is therefore required to reduce the dose delivered in CT scans without compromising the image quality. Several parameters like applied potential, tube current, scan length, pitch etc. influence the dose delivered in CT scans. For optimization of patient dose and image quality, all modern CT scanners are enabled with Automatic Exposure Control (AEC) systems. The aim of this work is to compare the dose delivered during CT scans performed with and without AEC in order to estimate the effectiveness of AEC techniques used in CT scanners of various manufacturer

  13. Low-cost extrapolation method for maximal LTE radio base station exposure estimation: test and validation.

    Science.gov (United States)

    Verloock, Leen; Joseph, Wout; Gati, Azeddine; Varsier, Nadège; Flach, Björn; Wiart, Joe; Martens, Luc

    2013-06-01

    An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on downlink band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2×2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders.

  14. Low-cost extrapolation method for maximal lte radio base station exposure estimation: Test and validation

    International Nuclear Information System (INIS)

    Verloock, L.; Joseph, W.; Gati, A.; Varsier, N.; Flach, B.; Wiart, J.; Martens, L.

    2013-01-01

    An experimental validation of a low-cost method for extrapolation and estimation of the maximal electromagnetic-field exposure from long-term evolution (LTE) radio base station installations are presented. No knowledge on down-link band occupation or service characteristics is required for the low-cost method. The method is applicable in situ. It only requires a basic spectrum analyser with appropriate field probes without the need of expensive dedicated LTE decoders. The method is validated both in laboratory and in situ, for a single-input single-output antenna LTE system and a 2x2 multiple-input multiple-output system, with low deviations in comparison with signals measured using dedicated LTE decoders. (authors)

  15. Thrombosis, systemic and cardiac oxidative stress and DNA damage induced by pulmonary exposure to diesel exhaust particles, and the effect of nootkatone thereon.

    Science.gov (United States)

    Nemmar, Abderrahim; Al-Salam, Suhail; Beegam, Sumaya; Yuvaraju, Priya; Ali, Badreldin H

    2018-01-05

    Adverse cardiovascular effects of particulate air pollution persist even at lower concentrations than those of the current air quality limit. Therefore, identification of safe and effective measures against particles-induced cardiovascular toxicity is needed. Nootkatone is a sesquiterpenoid in grapefruit with diverse bioactivities including anti-inflammatory and antioxidant effects. However, its protective effect on the cardiovascular injury induced by diesel exhaust particles (DEP) has not been studied before. We assessed the possible protective effect of nootkatone (90 mg/kg) administered by gavage 1h before intratracheal (i.t.) instillation of DEP (30 μg/mouse). Twenty-four h following the i.t. administration of DEP various thrombotic and cardiac parameters were assessed. Nootkatone inhibited the prothrombotic effect induced by DEP in pial arterioles and venules in vivo and platelet aggregation in whole blood in vitro. Also, nootkatone prevented the shortening of activated partial thromboplastin time and prothrombin time induced by DEP. Nootkatone inhibited the increase of plasma concentration of fibrinogen, plasminogen activator inhibitor-1, interleukin-6 and lipid peroxidation induced by DEP. Immunohistochemically, hearts showed an analogous increase in glutathione and nuclear factor erythroid-derived 2-like 2 (Nrf2) expression by cardiac myocytes and endothelial cells following DEP exposure, and these effects were enhanced in mice treated with nootkatone+DEP. Likewise, heme oxygenase-1 (HO-1) was increased in mice treated with nootkatone+DEP compared with those treated with DEP or nootkatone+saline. The DNA damage caused by DEP was prevented by nootkatoone pretreatment. In conclusion, nootkatoone alleviates DEP-induced thrombogenicity and systemic and cardiac oxidative stress and DNA damage, at least partly, through Nrf2 and HO-1 activation.

  16. Collective effective dose equivalent, population doses and risk estimates from occupational exposures in Japan

    International Nuclear Information System (INIS)

    Maruyama, Takashi; Nishizawa, Kanae; Kumamoto, Yoshikazu; Iwai, Kazuo; Mase, Naomichi.

    1993-01-01

    Collective dose equivalent and population dose from occupational exposures in Japan, 1988 were estimated on the basis of a nationwide survey. The survey was conducted on annual collective dose equivalents by sex, age group and type of radiation work for about 0.21 million workers except for the workers in nuclear power stations. The data on the workers in nuclear power stations were obtained from the official report of the Japan Nuclear Safety Commission. The total number of workers including nuclear power stations was estimated to be about 0.26 million. Radiation works were subdivided as follows: medical works including dental; non-atomic energy industry; research and education; atomic energy industry and nuclear power station. For the determination of effective dose equivalent and population dose, organ or tissue doses were measured with a phantom experiment. The resultant doses were compared with the doses previously calculated using a chord length technique and with data from ICRP publications. The annual collective effective dose equivalent were estimated to be about 21.94 person·Sv for medical workers, 7.73 person·Sv for industrial workers, 0.75 person·Sv for research and educational workers, 2.48 person·Sv for atomic energy industry and 84.4 person ·Sv for workers in nuclear power station. The population doses were calculated to be about 1.07 Sv for genetically significant dose, 0.89 Sv for leukemia significant dose and 0.42 Sv for malignant significant dose. The population risks were estimated using these population doses. (author)

  17. A Method to Estimate Students’ Exposure to Road Traffic Noise Events

    Directory of Open Access Journals (Sweden)

    Simone Secchi

    2018-03-01

    Full Text Available The correlation between exposure to traffic noise and students’ performance and annoyance has been investigated in literature mainly considering the relationship between indoor equivalent A-weighted sound pressure level (LAeq and students’ cognitive impairment. Annoyance is frequently related to the effect of short-duration noise events characterized by high sound pressure levels, such as those due to aircraft fly-over and pass-by of buses, heavy trucks, motorcycles, or street sweepers. These noise events are often described, over specific measurement periods, in terms of maximum A-weighted sound pressure level, LAmax, or statistical levels, such as LA1 or LA10. This aspect is not considered in the noise maps drawn in accordance with the European Environmental Noise Directive, as they provide the LAeq only, determined over day, evening, and night periods. In this paper, students’ exposure to road traffic noise is analyzed by means of regression equations obtained by the authors between LAeq and A-weighted maximum and statistical levels due to road traffic noise. The traffic noise of 28 urban streets was monitored during the opening period of Italian schools. A method is described to estimate students’ exposure to noise from data made available on noise maps by the municipalities of metropolitan areas. The application of this method to the case study of Florence shows that almost 60% of students from municipal primary and lower secondary schools could be exposed to the maximum sound pressure level (SPL inside the classroom greater than 55 dB(A every hour, probably exceeding the typical background noise in classrooms by more than 10 dB.

  18. Dose estimate of exposure to radioisotopes in molecular and cellular biology

    International Nuclear Information System (INIS)

    Onado, C.; Faretta, M.; Ubezio, P.

    1999-01-01

    A method for prospectively evaluating the annual equivalent doses and effective dose to biomedical researchers working with unsealed radioisotopes, and their classification, is presented here. Simplified formulae relate occupational data to a reasonable overestimate of the annual effective dose, and the equivalent doses to the hands and to the skin. The procedure, up to the classification of personnel and laboratories, can be made fully automatic, using a common spreadsheet on a personal computer. The method is based on occupational data, accounting for the amounts of each radioisotope used by a researcher, the time of exposure and the overall amounts employed in the laboratories where experiments are performed. The former data serve to forecast a contribution to the dose arising from a researcher's own work, the latter to a forecast of an 'environmental' contribution deriving simply from the presence in a laboratory where other people are working with radioisotopes. The estimates of the doses due to one's own radioisotope handling and to 'environment' were corrected for accidental exposure, considered as a linear function of the manipulated activity or of the time spent in the laboratories respectively, and summed up to give the effective dose. The effective dose associated with some common experiments in molecular and cellular biology is pre-evaluated by this method. (author)

  19. Bioassay of hair for estimation of body burden by tritium exposure

    International Nuclear Information System (INIS)

    Takeda, Hiroshi; Iwakura, Tetsuo

    1989-01-01

    For accurate estimation of radiation dose to human body from tritium exposure, it is needed to assess the concentration of tritium organically bound to the tissue constituents(OBT) as well as body water tritium. Since hair is an easily accessible tissue, it seems to be interesting to study the possibility of using hair for this purpose. In the present study, the pattern of tritium incorporation into hair and the quantitative relationship between OBT content in hair and in other internal tissues were investigated in rats exposed singly or continously to tritiated water, tritiated leucine and tritiated glycine. The rate of tritium incorporation into hair was slower than that into other tissues and the maximum concentrations were found on the 15-30th day after a single ingestion. The alterations in the concentration of OBT in internal tissues due to the difference of chemical form of ingested tritium were reflected on the OBT concentration in hair. Especially, the OBT content in hair under the condition of continuous exposure was almost the same as that in other tissues. These findings indicate the validity of hair analysis as a means for assessing OBT deposition in the body or tissues. (author)

  20. Estimating dose rates to organs as a function of age following internal exposure to radionuclides

    International Nuclear Information System (INIS)

    Leggett, R.W.; Eckerman, K.F.; Dunning, D.E. Jr.; Cristy, M.; Crawford-Brown, D.J.; Williams, L.R.

    1984-03-01

    The AGEDOS methodology allows estimates of dose rates, as a function of age, to radiosensitive organs and tissues in the human body at arbitrary times during or after internal exposure to radioactive material. Presently there are few, if any, radionuclides for which sufficient metabolic information is available to allow full use of all features of the methodology. The intention has been to construct the methodology so that optimal information can be gained from a mixture of the limited amount of age-dependent, nuclide-specific data and the generally plentiful age-dependent physiological data now available. Moreover, an effort has been made to design the methodology so that constantly accumulating metabolic information can be incorporated with minimal alterations in the AGEDOS computer code. Some preliminary analyses performed by the authors, using the AGEDOS code in conjunction with age-dependent risk factors developed from the A-bomb survivor data and other studies, has indicated that the doses and subsequent risks of eventually experiencing radiogenic cancers may vary substantially with age for some exposure scenarios and may be relatively invariant with age for other scenarios. We believe that the AGEDOS methodology provides a convenient and efficient means for performing the internal dosimetry

  1. Estimating burden and disease costs of exposure to endocrine-disrupting chemicals in the European union.

    Science.gov (United States)

    Trasande, Leonardo; Zoeller, R Thomas; Hass, Ulla; Kortenkamp, Andreas; Grandjean, Philippe; Myers, John Peterson; DiGangi, Joseph; Bellanger, Martine; Hauser, Russ; Legler, Juliette; Skakkebaek, Niels E; Heindel, Jerrold J

    2015-04-01

    Rapidly increasing evidence has documented that endocrine-disrupting chemicals (EDCs) contribute substantially to disease and disability. The objective was to quantify a range of health and economic costs that can be reasonably attributed to EDC exposures in the European Union (EU). A Steering Committee of scientists adapted the Intergovernmental Panel on Climate Change weight-of-evidence characterization for probability of causation based upon levels of available epidemiological and toxicological evidence for one or more chemicals contributing to disease by an endocrine disruptor mechanism. To evaluate the epidemiological evidence, the Steering Committee adapted the World Health Organization Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group criteria, whereas the Steering Committee adapted definitions recently promulgated by the Danish Environmental Protection Agency for evaluating laboratory and animal evidence of endocrine disruption. Expert panels used the Delphi method to make decisions on the strength of the data. Expert panels achieved consensus at least for probable (>20%) EDC causation for IQ loss and associated intellectual disability, autism, attention-deficit hyperactivity disorder, childhood obesity, adult obesity, adult diabetes, cryptorchidism, male infertility, and mortality associated with reduced testosterone. Accounting for probability of causation and using the midpoint of each range for probability of causation, Monte Carlo simulations produced a median cost of €157 billion (or $209 billion, corresponding to 1.23% of EU gross domestic product) annually across 1000 simulations. Notably, using the lowest end of the probability range for each relationship in the Monte Carlo simulations produced a median range of €109 billion that differed modestly from base case probability inputs. EDC exposures in the EU are likely to contribute substantially to disease and dysfunction across the life course with costs in

  2. Estimation of radiation exposure of prospectively triggered 128-slice computed tomography coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ketelsen, D.; Fenchel, M.; Thomas, C.; Boehringer, N.; Tsiflikas, I.; Kaempf, M.; Syha, R.; Claussen, C.D.; Heuschmid, M. [Tuebingen Univ. (Germany). Abt. fuer Diagnostische und Interventionelle Radiologie; Buchgeister, M. [Tuebingen Univ. (Germany). Medizinische Physik

    2010-12-15

    Purpose: To estimate the effective dose of prospectively triggered computed tomography coronary angiography (CTCA) in step-and-shoot (SAS) mode, depending on the tube current and tube voltage modulation. Materials and Methods: For dose measurements, an Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used. The effective dose was calculated according to ICRP 103. Exposure was performed on a 128-slice single source scanner providing a collimation of 128 x 0.6 mm and a rotation time of 0.38 seconds. CTCA in the SAS mode was acquired with variation of the tube current (160, 240, 320 mAs) and tube voltage (100, 120, 140 kV) at a simulated heart rate of 60 beats per minute and a scan range of 13.5 cm. Results: Depending on gender, tube current and tube voltage, the effective dose of a CTCA in SAS mode varies from 2.8 to 10.8 mSv. Due to breast tissue in the primary scan range, exposure in the case of females showed an increase of up to 60.0 {+-}.4 % compared to males. The dose reduction achieved by a reduction of tube current showed a significant positive, linear correlation to effective dose with a possible decrease in the effective dose of up to 60.4 % (r = 0.998; p = 0.044). Disproportionately high, the estimated effective dose can be reduced by using a lower tube voltage with a dose reduction of up to 52.4 %. Conclusion: Further substantial dose reduction of low-dose CTCA in SAS mode can be achieved by adapting the tube current and tube voltage and should be implemented in the clinical routine, i.e. adapting those protocol parameters to patient body weight. (orig.).

  3. Possible health hazards for cardiac pacemaker wearers from exposure to electromagnetic fields. L'exposition aux champs electromagnetiques: Risques pour la sante des porteurs de stimulateur cardiaque

    Energy Technology Data Exchange (ETDEWEB)

    1988-03-01

    Cardiac pacemakers are used to provide electrical stimulation to the heart when the heart's natural rhythm is interrupted. This study shows that they can be susceptible to electromagnetic fields. Pacemakers are well protected against common electromagnetic fields, such as those from household appliances. But intense electomagnetic fields, such as those found in some industrial settings, could affect the functioning of the pacemaker. Such interference may cause the pacemaker wearer to feel dizzy or experience an accelerated heartbeat. While this is not fatal, the pacemaker wearer should try to move away from the source of the interfering field and avoid situations in which interference could arise. After experiencing any of these symptoms, the pacemaker wearer should contact a physician. Potential sources of electromagnetic interference should be identified and characterized to determine if there could be an interference hazard. Exposure to interfering electomagnetic fields should be minimized. 7 refs., 1 fig.

  4. Estimation of quantitative levels of diesel exhaust exposure and the health impact in the contemporary Australian mining industry.

    Science.gov (United States)

    Peters, Susan; de Klerk, Nicholas; Reid, Alison; Fritschi, Lin; Musk, Aw Bill; Vermeulen, Roel

    2017-03-01

    To estimate quantitative levels of exposure to diesel exhaust expressed by elemental carbon (EC) in the contemporary mining industry and to describe the excess risk of lung cancer that may result from those levels. EC exposure has been monitored in Western Australian miners since 2003. Mixed-effects models were used to estimate EC levels for five surface and five underground occupation groups (as a fixed effect) and specific jobs within each group (as a random effect). Further fixed effects included sampling year and duration, and mineral mined. On the basis of published risk functions, we estimated excess lifetime risk of lung cancer mortality for several employment scenarios. Personal EC measurements (n=8614) were available for 146 different jobs at 124 mine sites. The mean estimated EC exposure level for surface occupations in 2011 was 14 µg/m 3 for 12 hour shifts. Levels for underground occupation groups ranged from 18 to 44 µg/m 3 . Underground diesel loader operators had the highest exposed specific job: 59 µg/m 3 . A lifetime career (45 years) as a surface worker or underground miner, experiencing exposure levels as estimated for 2011 (14 and 44 µg/m 3 EC), was associated with 5.5 and 38 extra lung cancer deaths per 1000 males, respectively. EC exposure levels in the contemporary Australian mining industry are still substantial, particularly for underground workers. The estimated excess numbers of lung cancer deaths associated with these exposures support the need for implementation of stringent occupational exposure limits for diesel exhaust. 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/.

  5. Method of risk estimates for genetic, leukemogenic and carcinogenic effects from medical and occupational exposures

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, T; Maruyama, T [National Inst. of Radiological Sciences, Chiba (Japan)

    1980-12-01

    For the risk estimate of fatal malignancies, an effective dose was proposed on the basis of the assumption that the risk should be equal whether the whole body irradiated uniformly or whether there is non-uniform irradiation. The effective dose was defined by the product of organ or tissue doses and a weighting factor representing the proportion of risk factor for a fatal malignancy resulting from organ or tissue irradiation to the total malignant factor. The risk of malignancies can be derived by multiplying the malignant significant factor by the product of the risk factor and the effective dose. For the genetic risk, a significant factor was a relative child expectancy and organ or tissue doses were gonad doses. And, for the leukemogenic risk, a significant factor was the leukemia significant factor and organ or tissue dose was mean bone marrow dose. The present method makes it easy to estimate the risk for individuals and population from medical and occupational exposures. The variation with age and sex of risk rates for stochastic effects was discussed, and the present data on risk rates were compared with the variation of risk rates recommended by the International Commission on Radiological Protection.

  6. Exposure dose estimation of nursing personnel and visitors following "1"2"5I brachytherapy

    International Nuclear Information System (INIS)

    Nakazato, Kazuhisa; Kikuchi, Hirosumi; Hotta, Harumi; Nishizawa, Kunihide

    2007-01-01

    An automated access management system to the controlled sickrooms for "1"2"5I brachytherapy was developed. The system consists of access control and video surveillance units. The patients implanted "1"2"5I seeds were isolated for about 20 h after surgery in the controlled sickrooms. The maximum doses and dose rates of the nurses and visitors were estimated by using the legal upper limit activity of 1,300 MBq, the measured longest staying time, and the shortest distance between the patients and individuals. Video analysis revealed activities of the nurses, patients, and visitors in the controlled sickroom, and relationships between the access frequency and staying time. The nurses' measured doses ranged from 1 to 3 μSv, and averaged 1.6 μSv. The nurses' maximum dose and dose rate were 16 μSv and 5.6 nSv·h"-"1·MBq"-"1. The visitors' maximum dose and dose rate were 6 μSv and 2.6 nSv·h"-"1·MBq"-"1. The nurses and visitors' exposure doses per patient were estimated to be negligible compared with the annual limit of the public. (author)

  7. Comparing population exposure to multiple Washington earthquake scenarios for prioritizing loss estimation studies

    Science.gov (United States)

    Wood, Nathan J.; Ratliff, Jamie L.; Schelling, John; Weaver, Craig S.

    2014-01-01

    Scenario-based, loss-estimation studies are useful for gauging potential societal impacts from earthquakes but can be challenging to undertake in areas with multiple scenarios and jurisdictions. We present a geospatial approach using various population data for comparing earthquake scenarios and jurisdictions to help emergency managers prioritize where to focus limited resources on data development and loss-estimation studies. Using 20 earthquake scenarios developed for the State of Washington (USA), we demonstrate how a population-exposure analysis across multiple jurisdictions based on Modified Mercalli Intensity (MMI) classes helps emergency managers understand and communicate where potential loss of life may be concentrated and where impacts may be more related to quality of life. Results indicate that certain well-known scenarios may directly impact the greatest number of people, whereas other, potentially lesser-known, scenarios impact fewer people but consequences could be more severe. The use of economic data to profile each jurisdiction’s workforce in earthquake hazard zones also provides additional insight on at-risk populations. This approach can serve as a first step in understanding societal impacts of earthquakes and helping practitioners to efficiently use their limited risk-reduction resources.

  8. A single exposure to acrolein desensitizes baroreflex responsiveness and increases cardiac arrhythmias in normotensive and hypertensive rats

    Science.gov (United States)

    Background – Short-term exposure to air pollutants has been linked to acute cardiovascular morbidity and mortality. Even in the absence of overt symptoms, pollutants can cause subtle disruptions of internal regulatory mechanisms, which maintain homeostatic balance, thereby reduci...

  9. In Utero Exposure to a Cardiac Teratogen Causes Reversible Deficits in Postnatal Cardiovascular Function, But Altered Adaptation to the Burden of Pregnancy.

    Science.gov (United States)

    Aasa, Kristiina L; Maciver, Rebecca D; Ramchandani, Shyamlal; Adams, Michael A; Ozolinš, Terence R S

    2015-11-01

    Congenital heart defects (CHD) are the most common birth anomaly and while many resolve spontaneously by 1 year of age, the lifelong burden on survivors is poorly understood. Using a rat model of chemically induced CHD that resolve postnatally, we sought to characterize the postnatal changes in cardiac function, and to investigate whether resolved CHD affects the ability to adapt to the increased the cardiovascular (CV) burden of pregnancy. To generate rats with resolved CHD, pregnant rats were administered distilled water or dimethadione (DMO) [300 mg/kg b.i.d. on gestation day (gd) 9 and 10] and pups delivered naturally. To characterize structural and functional changes in the heart, treated and control offspring were scanned by echocardiography on postnatal day 4, 21, and 10-12 weeks. Radiotelemeters were implanted for continuous monitoring of hemodynamics. Females were mated and scanned by echocardiography on gd12 and gd18 during pregnancy. On gd18, maternal hearts were collected for structural and molecular assessment. Postnatal echocardiography revealed numerous structural and functional differences in treated offspring compared with control; however, these resolved by 10-12 weeks of age. The CV demand of pregnancy revealed differences between treated and control offspring with respect to mean arterial pressure, CV function, cardiac strain, and left ventricular gene expression. In utero exposure to DMO also affected the subsequent generation. Gd18 fetal and placental weights were increased in treated F2 offspring. This study demonstrates that in utero chemical exposure may permanently alter the capacity of the postnatal heart to adapt to pregnancy and this may have transgenerational effects. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Effect of individual parameter changes on the outcome of the estimated short-term dietary exposure to pesticides.

    Science.gov (United States)

    van der Velde-Koerts, Trijntje; Breysse, Nicolas; Pattingre, Lauriane; Hamey, Paul Y; Lutze, Jason; Mahieu, Karin; Margerison, Sam; Ossendorp, Bernadette C; Reich, Hermine; Rietveld, Anton; Sarda, Xavier; Vial, Gaelle; Sieke, Christian

    2018-06-03

    In 2015 a scientific workshop was held in Geneva, where updating the International Estimate of Short-Term Intake (IESTI) equations was suggested. This paper studies the effects of the proposed changes in residue inputs, large portions, variability factors and unit weights on the overall short-term dietary exposure estimate. Depending on the IESTI case equation, a median increase in estimated overall exposure by a factor of 1.0-6.8 was observed when the current IESTI equations are replaced by the proposed IESTI equations. The highest increase in the estimated exposure arises from the replacement of the median residue (STMR) by the maximum residue limit (MRL) for bulked and blended commodities (case 3 equations). The change in large portion parameter does not have a significant impact on the estimated exposure. The use of large portions derived from the general population covering all age groups and bodyweights should be avoided when large portions are not expressed on an individual bodyweight basis. Replacement of the highest residue (HR) by the MRL and removal of the unit weight each increase the estimated exposure for small-, medium- and large-sized commodities (case 1, case 2a or case 2b equations). However, within the EU framework lowering of the variability factor from 7 or 5 to 3 counterbalances the effect of changes in other parameters, resulting in an estimated overall exposure change for the EU situation of a factor of 0.87-1.7 and 0.6-1.4 for IESTI case 2a and case 2b equations, respectively.

  11. Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography. Comparison with cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Belge, Benedicte; Pasquet, Agnes; Vanoverschelde, Jean-Louis J.; Coche, Emmanuel; Gerber, Bernhard L.

    2006-01-01

    Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134±51 and 67±56 ml) were similar to those by MR (137±57 and 70±60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55±21 vs. 56±21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3±1.8 vs. 8.8±1.9 mm and 12.7±3.4 vs. 13.3±3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54±30 vs. 51±31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR. (orig.)

  12. Biological dose estimation for accidental supra-high dose gamma-ray exposure

    International Nuclear Information System (INIS)

    Chen, Y.; Yan, X.K.; Du, J.; Wang, Z.D.; Zhang, X.Q.; Zeng, F.G.; Zhou, P.K.

    2011-01-01

    To correctly estimate the biological dose of victims accidentally exposed to a very high dose of 60 Co gamma-ray, a new dose-effect curve of chromosomal dicentrics/multicentrics and rings in the supra-high dose range was established. Peripheral blood from two healthy men was irradiated in vitro with doses of 60 Co gamma-rays ranging from 6 to 22 Gy at a dose rate of 2.0 Gy/min. Lymphocytes were concentrated, cultured and harvested at 52 h, 68 h and 72 h. The numbers of dic + r were counted. The dose-effect curves were established and validated using comparisons with doses from the Tokai-mura accident and were then applied to two victims of supra-high dose exposure accident. The results indicated that there were no significant differences in chromosome aberration frequency among the different culture times from 52 h to 72 h. The 6-22 Gy dose-effect curve was fitted to a linear quadratic model Y = -2.269 + 0.776D - 7.868 x l0 -3 D 2 . Using this mathematic model, the dose estimates were similar to data from Tokai-mura which were estimated by PCC ring. Whole body average doses of 9.7 Gy and 18.1 Gy for two victims in the Jining accident were satisfactorily given. We established and successfully applied a new dose-effect curve of chromosomal dicentrics plus ring (dic + r) after 6-22 Gy γ-irradiation from a supra-high dose 60 Co gamma-ray accident.

  13. Spatial variations in estimated chronic exposure to traffic-related air pollution in working populations: A simulation

    Directory of Open Access Journals (Sweden)

    Cloutier-Fisher Denise

    2008-07-01

    Full Text Available Abstract Background Chronic exposure to traffic-related air pollution is associated with a variety of health impacts in adults and recent studies show that exposure varies spatially, with some residents in a community more exposed than others. A spatial exposure simulation model (SESM which incorporates six microenvironments (home indoor, work indoor, other indoor, outdoor, in-vehicle to work and in-vehicle other is described and used to explore spatial variability in estimates of exposure to traffic-related nitrogen dioxide (not including indoor sources for working people. The study models spatial variability in estimated exposure aggregated at the census tracts level for 382 census tracts in the Greater Vancouver Regional District of British Columbia, Canada. Summary statistics relating to the distributions of the estimated exposures are compared visually through mapping. Observed variations are explored through analyses of model inputs. Results Two sources of spatial variability in exposure to traffic-related nitrogen dioxide were identified. Median estimates of total exposure ranged from 8 μg/m3 to 35 μg/m3 of annual average hourly NO2 for workers in different census tracts in the study area. Exposure estimates are highest where ambient pollution levels are highest. This reflects the regional gradient of pollution in the study area and the relatively high percentage of time spent at home locations. However, for workers within the same census tract, variations were observed in the partial exposure estimates associated with time spent outside the residential census tract. Simulation modeling shows that some workers may have exposures 1.3 times higher than other workers residing in the same census tract because of time spent away from the residential census tract, and that time spent in work census tracts contributes most to the differences in exposure. Exposure estimates associated with the activity of commuting by vehicle to work were

  14. [Estimation of the excess of lung cancer mortality risk associated to environmental tobacco smoke exposure of hospitality workers].

    Science.gov (United States)

    López, M José; Nebot, Manel; Juárez, Olga; Ariza, Carles; Salles, Joan; Serrahima, Eulàlia

    2006-01-14

    To estimate the excess lung cancer mortality risk associated with environmental tobacco (ETS) smoke exposure among hospitality workers. The estimation was done using objective measures in several hospitality settings in Barcelona. Vapour phase nicotine was measured in several hospitality settings. These measurements were used to estimate the excess lung cancer mortality risk associated with ETS exposure for a 40 year working life, using the formula developed by Repace and Lowrey. Excess lung cancer mortality risk associated with ETS exposure was higher than 145 deaths per 100,000 workers in all places studied, except for cafeterias in hospitals, where excess lung cancer mortality risk was 22 per 100,000. In discoteques, for comparison, excess lung cancer mortality risk is 1,733 deaths per 100,000 workers. Hospitality workers are exposed to ETS levels related to a very high excess lung cancer mortality risk. These data confirm that ETS control measures are needed to protect hospital workers.

  15. Comparison of entrance exposure and signal-to-noise ratio between an SBDX prototype and a wide-beam cardiac angiographic system

    International Nuclear Information System (INIS)

    Speidel, Michael A.; Wilfley, Brian P.; Star-Lack, Josh M.; Heanue, Joseph A.; Betts, Timothy D.; Van Lysel, Michael S.

    2006-01-01

    The scanning-beam digital x-ray (SBDX) system uses an inverse geometry, narrow x-ray beam, and a 2-mm thick CdTe detector to improve the dose efficiency of the coronary angiographic procedure. Entrance exposure and large-area iodine signal-to-noise ratio (SNR) were measured with the SBDX prototype and compared to that of a clinical cardiac interventional system with image intensifier (II) and charge coupled device (CCD) camera (Philips H5000, MRC-200 x-ray tube, 72 kWp max). Phantoms were 18.6-35.0 cm acrylic with an iohexol-equivalent disk placed at midthickness (35 mg/cm 2 iodine radiographic density). Imaging was performed at 15 frame/s, with the disk at mechanical isocenter and an 11-cm object-plane field width. The II/CCD system was operated in cine mode with automatic exposure control. With the SBDX prototype at maximum x-ray output (120 kVp, 24.3 kWp), the SBDX SNR was 107%-69% of the II/CCD SNR, depending on phantom thickness, and the SBDX entrance exposure rate was 10.7-9.3 R/min (9.4-8.2 cGy/min air kerma). For phantoms where an equal-kVp imaging comparison was possible (≥23.3 cm), the SBDX SNR ranged from 47% to 69% of the II/CCD SNR while delivering 6% to 9% of the II/CCD entrance exposure rate. From these measurements it was determined that the relative SBDX entrance exposure at equal SNR would be 31%-16%. Results were consistent with a model for relative entrance exposure at equal SNR, which predicted a 3-7 times reduction in entrance exposure due to SBDX's comparatively low scatter fraction (5.5%-8.1% measured, including off-focus radiation), high detector detective quantum efficiency (66%-73%, measured from 70 to 120 kVp), and large entrance field area (1.7x-2.3x, for the same object-plane field width). With improvements to the system geometry, detector, and x-ray source, SBDX technology is projected to achieve conventional cine-quality SNR over a full range of patient thicknesses, with 5-10 times lower skin dose

  16. Short-Term Nose-Only Water-Pipe (Shisha Smoking Exposure Accelerates Coagulation and Causes Cardiac Inflammation and Oxidative Stress in Mice

    Directory of Open Access Journals (Sweden)

    Abderrahim Nemmar

    2015-01-01

    Full Text Available Background/Aim: Water-pipe smoking (WPS has acquired worldwide popularity, and is disseminating particularly rapidly in Europe and North America. However, little is known about the short-term cardiovascular effects of WPS. Methods: Presently, we assessed the short-term cardiovascular effects of nose-only exposure to mainstream WPS in BALB/c mice for 30 min/day for 5 consecutive days. Control mice were exposed to air. At the end of the exposure period, several cardiovascular endpoints were measured. Results: WPS did not affect the number of leukocytes and the plasma concentrations of C-reactive protein, tumor necrosis factor α (TNFα and interleukin-6 (IL-6. Likewise, plasma levels of lipid peroxidation (LPO, reduced glutathione (GSH and catalase were not affected by WPS. By contrast, WPS aggravated in vivo thrombosis by shortening the thrombotic occlusion time in pial arterioles and venules. The number of circulating platelets was reduced by WPS suggesting the occurrence of platelet aggregation in vivo. Elevated concentrations of fibrinogen and plasminogen activator inhibitor-1 were seen after the exposure to WPS. Blood samples taken from mice exposed to WPS and exposed to adenosine diphosphate showed more platelet aggregation. The heart concentrations of IL-6 and TNFα were augmented by WPS. Likewise, heart levels of LPO, reactive oxygen species and the antioxidants catalase and GSH were increased by WPS. However, the systolic blood pressure and heart rate were not affected by WPS. Conclusion: It can be concluded that short-term exposure to WPS exerts procoagulatory effects and induce cardiac inflammation and oxidative stress. At the time point investigated, there was no evidence for blood inflammation or oxidative stress.

  17. Estimating Margin of Exposure to Thyroid Peroxidase Inhibitors Using High-Throughput in vitro Data, High-Throughput Exposure Modeling, and Physiologically Based Pharmacokinetic/Pharmacodynamic Modeling

    Science.gov (United States)

    Leonard, Jeremy A.; Tan, Yu-Mei; Gilbert, Mary; Isaacs, Kristin; El-Masri, Hisham

    2016-01-01

    Some pharmaceuticals and environmental chemicals bind the thyroid peroxidase (TPO) enzyme and disrupt thyroid hormone production. The potential for TPO inhibition is a function of both the binding affinity and concentration of the chemical within the thyroid gland. The former can be determined through in vitro assays, and the latter is influenced by pharmacokinetic properties, along with environmental exposure levels. In this study, a physiologically based pharmacokinetic (PBPK) model was integrated with a pharmacodynamic (PD) model to establish internal doses capable of inhibiting TPO in relation to external exposure levels predicted through exposure modeling. The PBPK/PD model was evaluated using published serum or thyroid gland chemical concentrations or circulating thyroxine (T4) and triiodothyronine (T3) hormone levels measured in rats and humans. After evaluation, the model was used to estimate human equivalent intake doses resulting in reduction of T4 and T3 levels by 10% (ED10) for 6 chemicals of varying TPO-inhibiting potencies. These chemicals were methimazole, 6-propylthiouracil, resorcinol, benzophenone-2, 2-mercaptobenzothiazole, and triclosan. Margin of exposure values were estimated for these chemicals using the ED10 and predicted population exposure levels for females of child-bearing age. The modeling approach presented here revealed that examining hazard or exposure alone when prioritizing chemicals for risk assessment may be insufficient, and that consideration of pharmacokinetic properties is warranted. This approach also provides a mechanism for integrating in vitro data, pharmacokinetic properties, and exposure levels predicted through high-throughput means when interpreting adverse outcome pathways based on biological responses. PMID:26865668

  18. A preliminary estimate of the EUVE cumulative distribution of exposure time on the unit sphere. [Extreme Ultra-Violet Explorer

    Science.gov (United States)

    Tang, C. C. H.

    1984-01-01

    A preliminary study of an all-sky coverage of the EUVE mission is given. Algorithms are provided to compute the exposure of the celestial sphere under the spinning telescopes, taking into account that during part of the exposure time the telescopes are blocked by the earth. The algorithms are used to give an estimate of exposure time at different ecliptic latitudes as a function of the angle of field of view of the telescope. Sample coverage patterns are also given for a 6-month mission.

  19. Estimate of lifetime excess lung cancer risk due to indoor exposure to natural radon-222 daughters in Korea

    International Nuclear Information System (INIS)

    Si-Young Chang; Jeong-Ho Lee; Chung-Woo Ha

    1993-01-01

    Lifetime excess lung cancer risk due to indoor 222 Rn daughters exposure in Korea was quantitatively estimated by a modified relative risk projection model proposed by the U.S. National Academy of Science and the recent Korean life table data. The lifetime excess risk of lung cancer death attributable to annual constant exposure to Korean indoor radon daughters was estimated to be about 230/10 6 per WLM, which seemed to be nearly in the median of the range of 150-450/10 6 per WLM reported by the UNSCEAR in 1988. (1 fig., 2 tabs.)

  20. PEDIC - A COMPUTER PROGRAM TO ESTIMATE THE EFFECT OF EVACUATION ON POPULATION EXPOSURE FOLLOWING ACUTE RADIONUCLIDE RELEASES TO THE ATOMSPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Strenge, D. L.; Peloquin, R. A.

    1981-01-01

    The computer program PEDIC is described for estimation of the effect of evacuation on population exposure. The program uses joint frequency, annual average meteorological data and a simple population evacuation model to estimate exposure reduction due to movement of people away from radioactive plumes following an acute release of activity. Atmospheric dispersion is based on a sector averaged Gaussian model with consideration of plume rise and building wake effects. Appendices to the report provide details of the computer program design, a program listing, input card preparation instructions and sample problems.

  1. Estimates of Environmental Exposure to Radiofrequency Electromagnetic Fields and Risk of Lymphoma Subtypes.

    Science.gov (United States)

    Satta, G; Mascia, N; Serra, T; Salis, A; Saba, L; Sanna, S; Zucca, M G; Angelucci, E; Gabbas, A; Culurgioni, F; Pili, P; Mura, E; Cappai, M; Ennas, M G; Cocco, P

    2018-05-01

    We investigated the association between environmental exposure to radiofrequency electromagnetic fields (RF-EMF) and risk of lymphoma subtypes in a case-control study comprised of 322 patients and 444 individuals serving as controls in Sardinia, Italy in 1998-2004. Questionnaire information included the self-reported distance of the three longest held residential addresses from fixed radio-television transmitters and mobile phone base stations. We georeferenced the residential addresses of all study subjects and obtained the spatial coordinates of mobile phone base stations. For each address within a 500-meter radius from a mobile phone base station, we estimated the RF-EMF intensity using predictions from spatial models, and we performed RF-EMF measurements at the door in the subset of the longest held addresses within a 250-meter radius. We calculated risk of lymphoma and its major subtypes associated with the RF-EMF exposure metrics with unconditional logistic regression, adjusting by age, gender and years of education. In the analysis of self-reported data, risk associated with residence in proximity (within 50 meters) to fixed radio-television transmitters was likewise elevated for lymphoma overall [odds ratio = 2.7, 95% confidence interval = 1.5-4.6], and for the major lymphoma subtypes. With reference to mobile phone base stations, we did not observe an association with either the self-reported, or the geocoded distance from mobile phone base stations. RF-EMF measurements did not vary by case-control status. By comparing the self-reports to the geocoded data, we discovered that the cases tended to underestimate the distance from mobile phone base stations differentially from the controls ( P = 0.073). The interpretation of our findings is compromised by the limited study size, particularly in the analysis of the individual lymphoma subtypes, and the unavailability of the spatial coordinates of radio-television transmitters. Nonetheless, our results do not

  2. Federal guidelines for estimating external exposure of radiation workers in Russia

    International Nuclear Information System (INIS)

    Chizhov, K.; Kryuchkov, V.; Mark, N.K.; Szoeke, I.; Sneve, M.K.

    2017-01-01

    In this paper, an overview of Russian federal guidelines for optimizing work procedures in terms of radiation protection for planned field work is presented. The general provisions, procedures and methods for applying the principles of optimization are provided in accordance with the Radiation Safety Standards (NRB-99/2009) and Basic sanitary rules of radiation safety (OSPORB-99/2010). Jobs in environments with actual or potential radiation hazards shall be planned on the basis of the principle of optimization in order to prevent unexpected exposure of the personnel. Control and optimization of dose to workers is a continuous process, which is carried out at various stages of radiation-hazardous work under constant involvement of the personnel in the planning procedure. Implementation of the principle of optimization should include considerations for human and organizational aspects for ensuring high level safety. The planning and optimization process includes education and training of personnel, estimation of radiation doses for the upcoming work, preparations for unplanned situations, and implementation of practical safety measures within the targeted radiation-hazardous works. The optimization principle is most important in the planning phase where uncertainties in planned exposure must be considered. Variability of radiation risks related to different scenarios (choices) can be managed by modern simulation technology, and use of advanced tools (software) for simulating planned activities and conditions in digital models including the environment (premises of an industrial complex) with dynamic visualization of the radiation exposure conditions. Existing hardware and emerging information technologies allow practical application of such techniques. Application of advanced information technology can reduce uncertainties related to the radiation environment by turning invisible radiation into directly perceivable risk information. In addition, virtual reality

  3. Measurement errors in the assessment of exposure to solar ultraviolet radiation and its impact on risk estimates in epidemiological studies.

    Science.gov (United States)

    Dadvand, Payam; Basagaña, Xavier; Barrera-Gómez, Jose; Diffey, Brian; Nieuwenhuijsen, Mark

    2011-07-01

    To date, many studies addressing long-term effects of ultraviolet radiation (UVR) exposure on human health have relied on a range of surrogates such as the latitude of the city of residence, ambient UVR levels, or time spent outdoors to estimate personal UVR exposure. This study aimed to differentiate the contributions of personal behaviour and ambient UVR levels on facial UVR exposure and to evaluate the impact of using UVR exposure surrogates on detecting exposure-outcome associations. Data on time-activity, holiday behaviour, and ambient UVR levels were obtained for adult (aged 25-55 years old) indoor workers in six European cities: Athens (37°N), Grenoble (45°N), Milan (45°N), Prague (50°N), Oxford (52°N), and Helsinki (60°N). Annual UVR facial exposure levels were simulated for 10,000 subjects for each city, using a behavioural UVR exposure model. Within-city variations of facial UVR exposure were three times larger than the variation between cities, mainly because of time-activity patterns. In univariate models, ambient UVR levels, latitude and time spent outdoors, each accounted for less than one fourth of the variation in facial exposure levels. Use of these surrogates to assess long-term exposure to UVR resulted in requiring more than four times more participants to achieve similar statistical power to the study that applied simulated facial exposure. Our results emphasise the importance of integrating both personal behaviour and ambient UVR levels/latitude in exposure assessment methodologies.

  4. Estimating survival probabilities by exposure levels: utilizing vital statistics and complex survey data with mortality follow-up.

    Science.gov (United States)

    Landsman, V; Lou, W Y W; Graubard, B I

    2015-05-20

    We present a two-step approach for estimating hazard rates and, consequently, survival probabilities, by levels of general categorical exposure. The resulting estimator utilizes three sources of data: vital statistics data and census data are used at the first step to estimate the overall hazard rate for a given combination of gender and age group, and cohort data constructed from a nationally representative complex survey with linked mortality records, are used at the second step to divide the overall hazard rate by exposure levels. We present an explicit expression for the resulting estimator and consider two methods for variance estimation that account for complex multistage sample design: (1) the leaving-one-out jackknife method, and (2) the Taylor linearization method, which provides an analytic formula for the variance estimator. The methods are illustrated with smoking and all-cause mortality data from the US National Health Interview Survey Linked Mortality Files, and the proposed estimator is compared with a previously studied crude hazard rate estimator that uses survey data only. The advantages of a two-step approach and possible extensions of the proposed estimator are discussed. Copyright © 2015 John Wiley & Sons, Ltd.

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

    Science.gov (United States)

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

    2012-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-15

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

  7. Letter to the Editor: Applications Air Q Model on Estimate Health Effects Exposure to Air Pollutants

    Directory of Open Access Journals (Sweden)

    Gholamreza Goudarzi

    2016-02-01

    Full Text Available Epidemiologic studies in worldwide have measured increases in mortality and morbidity associated with air pollution (1-3. Quantifying the effects of air pollution on the human health in urban area causes an increasingly critical component in policy discussion (4-6. Air Q model was proved to be a valid and reliable tool to predicts health effects related to criteria  pollutants (particulate matter (PM, ozone (O3, nitrogen dioxide (NO2, sulfur dioxide (SO2, and carbon monoxide (CO, determinate  the  potential short term effects of air pollution  and allows the examination of various scenarios in which emission rates of pollutants are varied (7,8. Air Q software provided by the WHO European Centre for Environment and Health (ECEH (9. Air Q model is based on cohort studies and used to estimates of both attributable average reductions in life-span and numbers of mortality and morbidity associated with exposure to air pollution (10,11. Applications

  8. The estimation of risks from the induction of recessive mutations after exposure to ionising radiation

    International Nuclear Information System (INIS)

    Searle, A.G.; Edwards, J.H.

    1986-01-01

    Induced recessive mutations can cause harm by (1) partnership with a defective allele already established in the population; (2) partnership with another recessive mutation induced at the same locus; (3) the formation of homozygous descendants, that is, identify by descent; and (4) heterozygous effects. Calculations based on a combination of data from observations on human populations and from mouse experiments suggest that an extra genetically significant dose of 1 cGy X or γ irradiation received by each parent in a stable population with a million liveborn offspring would induce up to 1200 extra recessive mutations. From partnership effects, about one extra case of recessive disease would be expected in the following 10 generations. Homozygosity resulting from identity by descent could not normally occur until the fourth generation after exposure but, on certain assumptions, about ten extra cases of recessive disease would be expected from this cause by the tenth generation. In the same period, about 250 recessive alleles would be eliminated in heterozygotes given 2.5% heterozygous disadvantage. These deleterious heterozygous effects should not be combined with those of dominants, as has been done in some previous risk estimates. It is considered unlikely that many radiation induced recessives would show heterozygous advantage. Certain dominants should be excluded from calculations of mutational risk because they are unlikely to be maintained by mutation. (author)

  9. Estimate of worker and patient exposures and quality control in hysterosalpingography exams

    International Nuclear Information System (INIS)

    Rodrigues, Barbara Beatriz Dias

    2006-06-01

    Hysterosalpingography (HSG) is a relatively frequent radiological procedure, which is used to access and study the uterine cavity and the tubary permeability. The estimate of the radiation doses received by the patients, and of the associated risks, has become of great interest in recent years. The importance in evaluating the received doses becomes even higher when the gonads region is irradiated; as in the case of hysterosalpingography, where the patients are relatively young, existing a high probability of future pregnancy. In HSG procedure the physician stays beside the patient, being also exposed. The purpose of this study was to analyze, during HSG procedures, the exposition of patients, measuring the kerma-area (P K,A ) product by using an ionization chamber of big area, to evaluate the doses received by the radiologist using thermoluminescent dosemeters and to evaluate the quality of image by means of qualitative methods. The results gotten during the accompaniment of 86 examinations had been the following ones: the average P K,A was 706 ± 388 cGy.cm 2 , to an average exposition time of 2 ± 1 minutes. In order to optimize the exposure of patients and workers, the time of scopy and the number of images should be reduced, whenever it is possible. Due to the significant values of equivalent dose received by the lens, the use of plumbiferous eyeglasses is recommended. (author)

  10. Earthquake shaking hazard estimates and exposure changes in the conterminous United States

    Science.gov (United States)

    Jaiswal, Kishor S.; Petersen, Mark D.; Rukstales, Kenneth S.; Leith, William S.

    2015-01-01

    A large portion of the population of the United States lives in areas vulnerable to earthquake hazards. This investigation aims to quantify population and infrastructure exposure within the conterminous U.S. that are subjected to varying levels of earthquake ground motions by systematically analyzing the last four cycles of the U.S. Geological Survey's (USGS) National Seismic Hazard Models (published in 1996, 2002, 2008 and 2014). Using the 2013 LandScan data, we estimate the numbers of people who are exposed to potentially damaging ground motions (peak ground accelerations at or above 0.1g). At least 28 million (~9% of the total population) may experience 0.1g level of shaking at relatively frequent intervals (annual rate of 1 in 72 years or 50% probability of exceedance (PE) in 50 years), 57 million (~18% of the total population) may experience this level of shaking at moderately frequent intervals (annual rate of 1 in 475 years or 10% PE in 50 years), and 143 million (~46% of the total population) may experience such shaking at relatively infrequent intervals (annual rate of 1 in 2,475 years or 2% PE in 50 years). We also show that there is a significant number of critical infrastructure facilities located in high earthquake-hazard areas (Modified Mercalli Intensity ≥ VII with moderately frequent recurrence interval).

  11. GPS-based Microenvironment Tracker (MicroTrac) Model to Estimate Time-Location of Individuals for Air Pollution Exposure Assessments: Model Evaluation in Central North Carolina

    Science.gov (United States)

    A critical aspect of air pollution exposure assessment is the estimation of the time spent by individuals in various microenvironments (ME). Accounting for the time spent in different ME with different pollutant concentrations can reduce exposure misclassifications, while failure...

  12. Estimated U.S. infant exposures to 3-MCPD esters and glycidyl esters from consumption of infant formula.

    Science.gov (United States)

    Spungen, Judith H; MacMahon, Shaun; Leigh, Jessica; Flannery, Brenna; Kim, Grace; Chirtel, Stuart; Smegal, Deborah

    2018-04-05

    A dietary exposure assessment was conducted for 3-monochloropropane-1,2-diol (3-MCPD) esters (3-MCPDE) and glycidyl esters (GE) in infant formulas available for consumption in the U.S. 3-MCPDE and GE are food contaminants generated during the deodorization of refined edible oils, which are used in infant formulas and other foods. 3-MCPDE and GE are of potential toxicological concern because these compounds are metabolized to free 3-MCPD and free glycidol in rodents, and may have the same metabolic fate in humans. Free 3-MCPD and free glycidol have been found to cause adverse effects in rodents. Dietary exposures to 3-MCPDE and GE from consumption of infant formulas are of particular interest because formulas are the sole or primary food source for some infants. In this analysis, U.S. Food and Drug Administration (FDA) data on 3-MCPDE and GE concentrations (as 3-MCPD and glycidol equivalents, respectively) in a small convenience sample of infant formulas were used to estimate exposures from consumption of formula by infants 0 - 6 months of age. 3-MCPDE and GE exposures based on mean concentrations in all formulas were estimated at 7 - 10 µg/kg bw/day and 2 µg/kg bw/day, respectively. Estimated mean exposures from consumption of formulas produced by individual manufacturers ranged from 1 - 14 µg/kg bw/day for 3-MCPDE, and from 1 - 3 µg/kg for GE.

  13. Can exposure to electromagnetic radiation in diathermy operators be estimated from interview data A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, A.I.; Skotte, J. (Central Hospital, Esbjerg (Denmark))

    1991-01-01

    As preparation for a case-control study dealing with possible teratogenic property of short waves, a pilot study was conducted in order to compare exposure assessment from different sources. In 11 physiotherapy clinics, exposure assessments based on interviews within 1 week among the exposed physiotherapists were compared with exposure assessments based on observations including measurements. It was possible to discriminate between recent high and low peak exposure. Furthermore, an interview index reflecting the duration of the exposure correlated to some extent with the corresponding measurements.

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

    International Nuclear Information System (INIS)

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

    1995-06-01

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

  15. Wide beam reconstruction for half-dose or half-time cardiac gated SPECT acquisitions: optimization of resources and reduction in radiation exposure

    International Nuclear Information System (INIS)

    Marcassa, Claudio; Campini, Riccardo; Zoccarato, Orazio; Calza, Paolo

    2011-01-01

    A new iterative reconstruction algorithm (WBR trademark) has been recently proposed for cardiac single photon emission computed tomography (SPECT). The WBR trademark technology is designed to reduce noise, improving lesion identification without affecting the image resolution, allowing SPECT studies with reduced count statistic. This allows for either half-time (HT) or half-dose (HD) cardiac SPECT, with image quality and quantitative data comparable to standard-time (ST) or standard-dose (SD) SPECT. Few data exist on the comparison between conventional filtered backprojection (FBP) and this new algorithm in a clinical setting. The aim of this study was to compare the performance of FBP and WBR trademark. Phantoms studies were performed to compare spatial resolution and contrast recovery with FBP, ordered subset expectation maximization (OSEM) and WBR trademark. A group of 92 patients, with different cardiac pathology, scheduled for a stress-rest SPECT were studied: 52 patients (group A) were injected with a SD of tracer and underwent both ST and HT SPECT; 40 patients (group B) were injected with a half dose of tracer and underwent ST SPECT and immediately after an additional SPECT at double time/projection (DT), to compensate for the low count statistic. A 2-day 99m Tc-sestamibi protocol was used in all patients. SD/ST and HD/DT SPECT were reconstructed with a conventional FBP; SD/HT and HD/ST SPECT were reconstructed with WBR trademark. The summed stress score (SSS) and summed rest score (SRS) were calculated; the left ventricular ejection fraction (LVEF) was automatically derived. In group A (SD), no significant differences were observed between ST FBP SPECT and HT WBR trademark in SSS (11.1 and 11.7, respectively) and SRS (9.4 and 10.3, respectively, NS). LVEF on rest acquisitions was also comparable (50% on ST SPECT and 49% on HT SPECT, NS); LVEF on post-stress studies in HT SPECT (46%) was lower than ST SPECT (50%), although not statistically significant. In

  16. Uncertainty in exposure of underground miners to radon daughters and the effect of uncertainty on risk estimates

    International Nuclear Information System (INIS)

    1989-10-01

    Studies of underground miners provide the principal basis for assessing the risk from radon daughter exposure. An important problem in all epidemiological studies of underground miners is the reliability of the estimates of the miners' exposures. This study examines the various sources of uncertainty in exposure estimation for the principal epidemiologic studies reported in the literature including the temporal and spatial variability of radon sources and, with the passage of time, changes to both mining methods and ventilation conditions. Uncertainties about work histories and the role of other hard rock mining experience are also discussed. The report also describes two statistical approaches, both based on Bayesian methods, by which the effects on the estimated risk coefficient of uncertainty in exposure (WLM) can be examined. One approach requires only an estimate of the cumulative WLM exposure of a group of miners, an estimate of the number of (excess) lung cancers potentially attributable to that exposure, and a specification of the uncertainty about the cumulative exposure of the group. The second approach is based on a linear regression model which incorporates errors (uncertainty) in the independent variable (WLM) and allows the dependent variable (cases) to be Poisson distributed. The method permits the calculation of marginal probability distributions for either slope (risk coefficient) or intercept. The regression model approach is applied to several published data sets from epidemiological studies of miners. Specific results are provided for each data set and apparent differences in risk coefficients are discussed. The studies of U.S. uranium miners, Ontario uranium miners and Czechoslovakian uranium miners are argued to provide the best basis for risk estimation at this time. In general terms, none of the analyses performed are inconsistent with a linear exposure-effect relation. Based on analyses of the overall miner groups, the most likely ranges

  17. Constructing Predictive Estimates for Worker Exposure to Radioactivity During Decommissioning: Analysis of Completed Decommissioning Projects - Master Thesis

    Energy Technology Data Exchange (ETDEWEB)

    Dettmers, Dana Lee; Eide, Steven Arvid

    2002-10-01

    An analysis of completed decommissioning projects is used to construct predictive estimates for worker exposure to radioactivity during decommissioning activities. The preferred organizational method for the completed decommissioning project data is to divide the data by type of facility, whether decommissioning was performed on part of the facility or the complete facility, and the level of radiation within the facility prior to decommissioning (low, medium, or high). Additional data analysis shows that there is not a downward trend in worker exposure data over time. Also, the use of a standard estimate for worker exposure to radioactivity may be a best estimate for low complete storage, high partial storage, and medium reactor facilities; a conservative estimate for some low level of facility radiation facilities (reactor complete, research complete, pits/ponds, other), medium partial process facilities, and high complete research facilities; and an underestimate for the remaining facilities. Limited data are available to compare different decommissioning alternatives, so the available data are reported and no conclusions can been drawn. It is recommended that all DOE sites and the NRC use a similar method to document worker hours, worker exposure to radiation (person-rem), and standard industrial accidents, injuries, and deaths for all completed decommissioning activities.

  18. The diesel exhaust in miners study: IV. Estimating historical exposures to diesel exhaust in underground non-metal mining facilities.

    NARCIS (Netherlands)

    Vermeulen, R.; Coble, J.B.; Lubin, J.H.; Portengen, L.; Blair, A.; Attfield, M.D.; Silverman, D.T.; Stewart, P.A.

    2010-01-01

    We developed quantitative estimates of historical exposures to respirable elemental carbon (REC) for an epidemiologic study of mortality, including lung cancer, among diesel-exposed miners at eight non-metal mining facilities [the Diesel Exhaust in Miners Study (DEMS)]. Because there were no

  19. Instrumental variables estimation of exposure effects on a time-to-event endpoint using structural cumulative survival models

    DEFF Research Database (Denmark)

    Martinussen, Torben; Vansteelandt, Stijn; Tchetgen Tchetgen, Eric J.

    2017-01-01

    The use of instrumental variables for estimating the effect of an exposure on an outcome is popular in econometrics, and increasingly so in epidemiology. This increasing popularity may be attributed to the natural occurrence of instrumental variables in observational studies that incorporate elem...

  20. Cultural and Demographic Factors Influencing Noise Exposure Estimates from Use of Portable Listening Devices in an Urban Environment

    Science.gov (United States)

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

    2014-01-01

    Purpose: This study examined listening levels and duration of portable listening devices (PLDs) used by people with diversity of ethnicity, education, music genre, and PLD manufacturer. The goal was to estimate participants' PLD noise exposure and identify factors influencing user behavior. Method: This study measured listening levels of 160…

  1. Response of TLD badge for the estimation of exposure conditions in diagnostic x-ray departments - use of lead aprons

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Chatterjee, S.; Bakshi, A.K.

    2002-01-01

    The present study was undertaken to ascertain the conditions of exposure of the TLD badge and to evaluate the inaccuracy involved in the estimation of dose received by the worker using an averaged lead apron transmission factor for the use of the badge above lead apron

  2. Fetal cardiac function in late-onset intrauterine growth restriction vs small-for-gestational age, as defined by estimated fetal weight, cerebroplacental ratio and uterine artery Doppler.

    Science.gov (United States)

    Pérez-Cruz, M; Cruz-Lemini, M; Fernández, M T; Parra, J A; Bartrons, J; Gómez-Roig, M D; Crispi, F; Gratacós, E

    2015-10-01

    Among late-onset small fetuses, a combination of estimated fetal weight (EFW), cerebroplacental ratio (CPR) and mean uterine artery (UtA) pulsatility index (PI) can predict a subgroup of fetuses with poor perinatal outcome; however, the association of these criteria with fetal cardiac structure and function is unknown. Our aim was to determine the presence and severity of signs indicating cardiac dysfunction in small fetuses, classified as intrauterine growth-restricted (IUGR) or small-for-gestational age (SGA), according to EFW, CPR and UtA-PI. A cohort of 209 late-onset small fetuses that were delivered > 34 weeks of gestation was divided in two categories: SGA (n = 59) if EFW was between the 3(rd) and 9(th) centiles with normal CPR and UtA-PI; and IUGR (n = 150) if EFW was  95(th) centile. The small population was compared with 150 appropriately grown fetuses (controls). Fetal cardiac morphometry and function were assessed by echocardiography using two-dimensional M-mode, conventional and tissue Doppler. Compared with controls, both IUGR and SGA fetuses showed larger and more globular hearts (mean left sphericity index ± SD: controls, 1.8 ± 0.3; SGA, 1.5 ± 0.2; and IUGR, 1.6 ± 0.3; P < 0.01) and showed signs of systolic and diastolic dysfunction, including decreased tricuspid annular plane systolic excursion (mean ± SD: controls, 8.2 ± 1.1; SGA, 7.4 ± 1.2; and IUGR, 6.9 ± 1.1; P < 0.001) and increased left myocardial performance index (mean ± SD: controls, 0.45 ± 0.14; SGA, 0.51 ± 0.08; and IUGR, 0.57 ± 0.1; P < 0.001). Despite a perinatal outcome comparable to that of normal fetuses, the population of so-defined SGA fetuses showed signs of prenatal cardiac dysfunction. This supports the concept that at least a proportion of them are not 'constitutionally small' and that further research is needed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

  3. Estimating population heat exposure and impacts on working people in conjunction with climate change

    Science.gov (United States)

    Kjellstrom, Tord; Freyberg, Chris; Lemke, Bruno; Otto, Matthias; Briggs, David

    2018-03-01

    Increased environmental heat levels as a result of climate change present a major challenge to the health, wellbeing and sustainability of human communities in already hot parts of this planet. This challenge has many facets from direct clinical health effects of daily heat exposure to indirect effects related to poor air quality, poor access to safe drinking water, poor access to nutritious and safe food and inadequate protection from disease vectors and environmental toxic chemicals. The increasing environmental heat is a threat to environmental sustainability. In addition, social conditions can be undermined by the negative effects of increased heat on daily work and life activities and on local cultural practices. The methodology we describe can be used to produce quantitative estimates of the impacts of climate change on work activities in countries and local communities. We show in maps the increasing heat exposures in the shade expressed as the occupational heat stress index Wet Bulb Globe Temperature. Some tropical and sub-tropical areas already experience serious heat stress, and the continuing heating will substantially reduce work capacity and labour productivity in widening parts of the world. Southern parts of Europe and the USA will also be affected. Even the lowest target for climate change (average global temperature change = 1.5 °C at representative concentration pathway (RCP2.6) will increase the loss of daylight work hour output due to heat in many tropical areas from less than 2% now up to more than 6% at the end of the century. A global temperature change of 2.7 °C (at RCP6.0) will double this annual heat impact on work in such areas. Calculations of this type of heat impact at country level show that in the USA, the loss of work capacity in moderate level work in the shade will increase from 0.17% now to more than 1.3% at the end of the century based on the 2.7 °C temperature change. The impact is naturally mainly occurring in the southern

  4. Estimating time-varying exposure-outcome associations using case-control data: logistic and case-cohort analyses.

    Science.gov (United States)

    Keogh, Ruth H; Mangtani, Punam; Rodrigues, Laura; Nguipdop Djomo, Patrick

    2016-01-05

    Traditional analyses of standard case-control studies using logistic regression do not allow estimation of time-varying associations between exposures and the outcome. We present two approaches which allow this. The motivation is a study of vaccine efficacy as a function of time since vaccination. Our first approach is to estimate time-varying exposure-outcome associations by fitting a series of logistic regressions within successive time periods, reusing controls across periods. Our second approach treats the case-control sample as a case-cohort study, with the controls forming the subcohort. In the case-cohort analysis, controls contribute information at all times they are at risk. Extensions allow left truncation, frequency matching and, using the case-cohort analysis, time-varying exposures. Simulations are used to investigate the methods. The simulation results show that both methods give correct estimates of time-varying effects of exposures using standard case-control data. Using the logistic approach there are efficiency gains by reusing controls over time and care should be taken over the definition of controls within time periods. However, using the case-cohort analysis there is no ambiguity over the definition of controls. The performance of the two analyses is very similar when controls are used most efficiently under the logistic approach. Using our methods, case-control studies can be used to estimate time-varying exposure-outcome associations where they may not previously have been considered. The case-cohort analysis has several advantages, including that it allows estimation of time-varying associations as a continuous function of time, while the logistic regression approach is restricted to assuming a step function form for the time-varying association.

  5. Estimating time-varying exposure-outcome associations using case-control data: logistic and case-cohort analyses

    Directory of Open Access Journals (Sweden)

    Ruth H. Keogh

    2016-01-01

    Full Text Available Abstract Background Traditional analyses of standard case-control studies using logistic regression do not allow estimation of time-varying associations between exposures and the outcome. We present two approaches which allow this. The motivation is a study of vaccine efficacy as a function of time since vaccination. Methods Our first approach is to estimate time-varying exposure-outcome associations by fitting a series of logistic regressions within successive time periods, reusing controls across periods. Our second approach treats the case-control sample as a case-cohort study, with the controls forming the subcohort. In the case-cohort analysis, controls contribute information at all times they are at risk. Extensions allow left truncation, frequency matching and, using the case-cohort analysis, time-varying exposures. Simulations are used to investigate the methods. Results The simulation results show that both methods give correct estimates of time-varying effects of exposures using standard case-control data. Using the logistic approach there are efficiency gains by reusing controls over time and care should be taken over the definition of controls within time periods. However, using the case-cohort analysis there is no ambiguity over the definition of controls. The performance of the two analyses is very similar when controls are used most efficiently under the logistic approach. Conclusions Using our methods, case-control studies can be used to estimate time-varying exposure-outcome associations where they may not previously have been considered. The case-cohort analysis has several advantages, including that it allows estimation of time-varying associations as a continuous function of time, while the logistic regression approach is restricted to assuming a step function form for the time-varying association.

  6. Exposure estimates based on broadband elf magnetic field measurements versus the ICNIRP multiple frequency rule

    International Nuclear Information System (INIS)

    Paniagua, Jesus M.; Rufo, Montana; Jimenez, Antonio; Pachon, Fernando T.; Carrero, Julian

    2015-01-01

    The evaluation of exposure to extremely low-frequency (ELF) magnetic fields using broadband measurement techniques gives satisfactory results when the field has essentially a single frequency. Nevertheless, magnetic fields are in most cases distorted by harmonic components. This work analyses the harmonic components of the ELF magnetic field in an outdoor urban context and compares the evaluation of the exposure based on broadband measurements with that based on spectral analysis. The multiple frequency rule of the International Commission on Non-ionizing Radiation Protection (ICNIRP) regulatory guidelines was applied. With the 1998 ICNIRP guideline, harmonics dominated the exposure with a 55 % contribution. With the 2010 ICNIRP guideline, however, the primary frequency dominated the exposure with a 78 % contribution. Values of the exposure based on spectral analysis were significantly higher than those based on broadband measurements. Hence, it is clearly necessary to determine the harmonic components of the ELF magnetic field to assess exposure in urban contexts. (authors)

  7. Concentrations of phthalates and bisphenol A in Norwegian foods and beverages and estimated dietary exposure in adults.

    Science.gov (United States)

    Sakhi, Amrit K; Lillegaard, Inger Therese L; Voorspoels, Stefan; Carlsen, Monica H; Løken, Elin B; Brantsæter, Anne L; Haugen, Margaretha; Meltzer, Helle M; Thomsen, Cathrine

    2014-12-01

    Phthalates and bisphenol A (BPA) are ubiquitous in our environment. These chemicals have been characterized as endocrine disruptors that can cause functional impairment of development and reproduction. Processed and packaged foods are among the major sources of human exposure to these chemicals. No previous report showing the levels of these chemicals in food items purchased in Norway is available. The aim of the present study was to determine the concentration of ten different phthalates and BPA in foods and beverages purchased on the Norwegian market and estimate the daily dietary exposure in the Norwegian adult population. Commonly consumed foods and beverages in Norway were purchased in a grocery store and analysed using gas- and liquid chromatography coupled with mass spectrometry. Daily dietary exposures to these chemicals in the Norwegian adult population were estimated using the latest National dietary survey, Norkost 3 (2010-2011). This study showed that phthalates and BPA are found in all foods and beverages that are common to consume in Norway. The detection frequency of phthalates in the food items varied from 11% for dicyclohexyl phthalate (DCHP) to 84% for di-iso-nonyl phthalate (DiNP), one of the substitutes for bis(2-ethylhexyl) phthalate (DEHP). BPA was found in 54% of the food items analysed. Among the different phthalates, the highest concentrations were found for DEHP and DiNP in the food items. Estimated dietary exposures were also equally high and dominated by DEHP and DiNP (400-500 ng/kg body weight (bw)/day), followed by di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), di-n-octyl phthalate (DnOP) and di-iso-decyl phthalate (DiDP) (30-40 ng/kg bw/day). Dimethyl phthalate (DMP), diethylphthalate (DEP) and DCHP had the lowest concentrations and the exposures were around 10-20 ng/kg bw/day. Estimated dietary exposure to BPA was 5 ng/kg bw/day. In general, levels of phthalates and BPA in foods and beverages from the Norwegian market

  8. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal

    2017-01-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth...... the notion that the developing adaptive immune system is particularly vulnerable to immunotoxicity during infancy. This vulnerability appears to be the greatest during the first 6 months after birth, where PFAS exposures are affected by breast-feeding....

  9. Reduction of radiation exposure and improvement of image quality with BMI-adapted prospective cardiac computed tomography and iterative reconstruction

    International Nuclear Information System (INIS)

    Hosch, Waldemar; Stiller, Wolfram; Mueller, Dirk; Gitsioudis, Gitsios; Welzel, Johanna; Dadrich, Monika; Buss, Sebastian J.; Giannitsis, Evangelos; Kauczor, Hans U.; Katus, Hugo A.; Korosoglou, Grigorios

    2012-01-01

    Purpose: To assess the impact of body mass index (BMI)-adapted protocols and iterative reconstruction algorithms (iDose) on patient radiation exposure and image quality in patients undergoing prospective ECG-triggered 256-slice coronary computed tomography angiography (CCTA). Methods: Image quality and radiation exposure were systematically analyzed in 100 patients. 60 Patients underwent prospective ECG-triggered CCTA using a non-tailored protocol and served as a ‘control’ group (Group 1: 120 kV, 200 mA s). 40 Consecutive patients with suspected coronary artery disease (CAD) underwent prospective CCTA, using BMI-adapted tube voltage and standard (Group 2: 100/120 kV, 100–200 mA s) versus reduced tube current (Group 3: 100/120 kV, 75–150 mA s). Iterative reconstructions were provided with different iDose levels and were compared to filtered back projection (FBP) reconstructions. Image quality was assessed in consensus of 2 experienced observers and using a 5-grade scale (1 = best to 5 = worse), and signal- and contrast-to-noise ratios (SNR and CNR) were quantified. Results: CCTA was performed without adverse events in all patients (n = 100, heart rate of 47–87 bpm and BMI of 19–38 kg/m 2 ). Patients examined using the non-tailored protocol in Group 1 had the highest radiation exposure (3.2 ± 0.4 mSv), followed by Group 2 (1.7 ± 0.7 mSv) and Group 3 (1.2 ± 0.6 mSv) (radiation savings of 47% and 63%, respectively, p < 0.001). Iterative reconstructions provided increased SNR and CNR, particularly when higher iDose level 5 was applied with Multi-Frequency reconstruction (iDose5 MFR) (14.1 ± 4.6 versus 21.2 ± 7.3 for SNR and 12.0 ± 4.2 versus 18.1 ± 6.6 for CNR, for FBP versus iDose5 MFR, respectively, p < 0.001). The combination of BMI adaptation with iterative reconstruction reduced radiation exposure and simultaneously improved image quality (subjective image quality of 1.4 ± 0.4 versus 1.9 ± 0.5 for Group 2 reconstructed using iDose5 MFR versus

  10. CARDIAC LYMPHOMA IN DOG

    Directory of Open Access Journals (Sweden)

    G. D. Cruz

    2016-11-01

    Full Text Available Lymphoma is a lymphoid tumor that originates in hematopoietic organs such as lymph node, spleen or liver. In dogs, the overall prevalence of cardiac tumors was estimated to be only 0.19% based on the results of the survey of a large database, and lymphomas accounts for approximately 2% of all cardiac tumors. In general, the involvement of the myocardium is rarely described in canine lymphoma. Currently, there is no evidence of a viral association with primary cardiac lymphoma in dogs, but other types of immunosuppression may contribute to abnormal events, such as involvement primary cardiac. The aim of this study was to analyze a case of sudden death of a bitch, SRD, aged 10, who had the final diagnosis of cardiac lymphoma.

  11. Evidence towards improved estimation of respiratory muscle effort from diaphragm mechanomyographic signals with cardiac vibration interference using sample entropy with fixed tolerance values.

    Directory of Open Access Journals (Sweden)

    Leonardo Sarlabous

    Full Text Available The analysis of amplitude parameters of the diaphragm mechanomyographic (MMGdi signal is a non-invasive technique to assess respiratory muscle effort and to detect and quantify the severity of respiratory muscle weakness. The amplitude of the MMGdi signal is usually evaluated using the average rectified value or the root mean square of the signal. However, these estimations are greatly affected by the presence of cardiac vibration or mechanocardiographic (MCG noise. In this study, we present a method for improving the estimation of the respiratory muscle effort from MMGdi signals that is robust to the presence of MCG. This method is based on the calculation of the sample entropy using fixed tolerance values (fSampEn, that is, with tolerance values that are not normalized by the local standard deviation of the window analyzed. The behavior of the fSampEn parameter was tested in synthesized mechanomyographic signals, with different ratios between the amplitude of the MCG and clean mechanomyographic components. As an example of application of this technique, the use of fSampEn was explored also in recorded MMGdi signals, with different inspiratory loads. The results with both synthetic and recorded signals indicate that the entropy parameter is less affected by the MCG noise, especially at low signal-to-noise ratios. Therefore, we believe that the proposed fSampEn parameter could improve estimates of respiratory muscle effort from MMGdi signals with the presence of MCG interference.

  12. Instrumental variables estimation of exposure effects on a time-to-event endpoint using structural cumulative survival models.

    Science.gov (United States)

    Martinussen, Torben; Vansteelandt, Stijn; Tchetgen Tchetgen, Eric J; Zucker, David M

    2017-12-01

    The use of instrumental variables for estimating the effect of an exposure on an outcome is popular in econometrics, and increasingly so in epidemiology. This increasing popularity may be attributed to the natural occurrence of instrumental variables in observational studies that incorporate elements of randomization, either by design or by nature (e.g., random inheritance of genes). Instrumental variables estimation of exposure effects is well established for continuous outcomes and to some extent for binary outcomes. It is, however, largely lacking for time-to-event outcomes because of complications due to censoring and survivorship bias. In this article, we make a novel proposal under a class of structural cumulative survival models which parameterize time-varying effects of a point exposure directly on the scale of the survival function; these models are essentially equivalent with a semi-parametric variant of the instrumental variables additive hazards model. We propose a class of recursive instrumental variable estimators for these exposure effects, and derive their large sample properties along with inferential tools. We examine the performance of the proposed method in simulation studies and illustrate it in a Mendelian randomization study to evaluate the effect of diabetes on mortality using data from the Health and Retirement Study. We further use the proposed method to investigate potential benefit from breast cancer screening on subsequent breast cancer mortality based on the HIP-study. © 2017, The International Biometric Society.

  13. Estimation of whole-body radiation exposure from brachytherapy for oral cancer using a Monte Carlo simulation

    International Nuclear Information System (INIS)

    Ozaki, Y.; Watanabe, H.; Kaida, A.; Miura, M.; Nakagawa, K.; Toda, K.; Yoshimura, R.; Sumi, Y.; Kurabayashi, T.

    2017-01-01

    Early stage oral cancer can be cured with oral brachytherapy, but whole-body radiation exposure status has not been previously studied. Recently, the International Commission on Radiological Protection Committee (ICRP) recommended the use of ICRP phantoms to estimate radiation exposure from external and internal radiation sources. In this study, we used a Monte Carlo simulation with ICRP phantoms to estimate whole-body exposure from oral brachytherapy. We used a Particle and Heavy Ion Transport code System (PHITS) to model oral brachytherapy with 192 Ir hairpins and 198 Au grains and to perform a Monte Carlo simulation on the ICRP adult reference computational phantoms. To confirm the simulations, we also computed local dose distributions from these small sources, and compared them with the results from Oncentra manual Low Dose Rate Treatment Planning (mLDR) software which is used in day-to-day clinical practice. We successfully obtained data on absorbed dose for each organ in males and females. Sex-averaged equivalent doses were 0.547 and 0.710 Sv with 192 Ir hairpins and 198 Au grains, respectively. Simulation with PHITS was reliable when compared with an alternative computational technique using mLDR software. We concluded that the absorbed dose for each organ and whole-body exposure from oral brachytherapy can be estimated with Monte Carlo simulation using PHITS on ICRP reference phantoms. Effective doses for patients with oral cancer were obtained.

  14. Validation of traffic-related air pollution exposure estimates for long-term studies

    NARCIS (Netherlands)

    Van Roosbroeck, S.

    2007-01-01

    This thesis describes a series of studies that investigate the validity of using outdoor concentrations and/or traffic-related indicator exposure variables as a measure for exposure assessment in epidemiological studies on the long-term effect of traffic-related air pollution. A pilot study was

  15. Estimating Benzene Exposure Level over Time and by Industry Type through a Review of Literature on Korea.

    Science.gov (United States)

    Park, Donguk; Choi, Sangjun; Ha, Kwonchul; Jung, Hyejung; Yoon, Chungsik; Koh, Dong-Hee; Ryu, Seunghun; Kim, Soogeun; Kang, Dongmug; Yoo, Kyemook

    2015-09-01

    The major purpose of this study is to construct a retrospective exposure assessment for benzene through a review of literature on Korea. Airborne benzene measurements reported in 34 articles were reviewed. A total of 15,729 individual measurements were compiled. Weighted arithmetic means [AM(w)] and their variance calculated across studies were summarized according to 5-year period intervals (prior to the 1970s through the 2010s) and industry type. Industries were classified according to Korea Standard Industrial Classification (KSIC) using information provided in the literature. We estimated quantitative retrospective exposure to benzene for each cell in the matrix through a combination of time and KSIC. Analysis of the AM(w) indicated reductions in exposure levels over time, regardless of industry, with mean levels prior to the 1980-1984 period of 50.4 ppm (n = 2,289), which dropped to 2.8 ppm (n = 305) in the 1990-1994 period, and to 0.1 ppm (n = 294) in the 1995-1999 period. There has been no improvement since the 2000s, when the AM(w) of 4.3 ppm (n = 6,211) for the 2005-2009 period and 4.5 ppm (n = 3,358) for the 2010-2013 period were estimated. A comparison by industry found no consistent patterns in the measurement results. Our estimated benzene measurements can be used to determine not only the possibility of retrospective exposure to benzene, but also to estimate the level of quantitative or semiquantitative retrospective exposure to benzene.

  16. Estimating Benzene Exposure Level over Time and by Industry Type through a Review of Literature on Korea

    Directory of Open Access Journals (Sweden)

    Donguk Park

    2015-09-01

    Full Text Available The major purpose of this study is to construct a retrospective exposure assessment for benzene through a review of literature on Korea. Airborne benzene measurements reported in 34 articles were reviewed. A total of 15,729 individual measurements were compiled. Weighted arithmetic means [AM(w] and their variance calculated across studies were summarized according to 5-year period intervals (prior to the 1970s through the 2010s and industry type. Industries were classified according to Korea Standard Industrial Classification (KSIC using information provided in the literature. We estimated quantitative retrospective exposure to benzene for each cell in the matrix through a combination of time and KSIC. Analysis of the AM(w indicated reductions in exposure levels over time, regardless of industry, with mean levels prior to the 1980–1984 period of 50.4 ppm (n = 2,289, which dropped to 2.8 ppm (n = 305 in the 1990–1994 period, and to 0.1 ppm (n = 294 in the 1995–1999 period. There has been no improvement since the 2000s, when the AM(w of 4.3 ppm (n = 6,211 for the 2005–2009 period and 4.5 ppm (n = 3,358 for the 2010–2013 period were estimated. A comparison by industry found no consistent patterns in the measurement results. Our estimated benzene measurements can be used to determine not only the possibility of retrospective exposure to benzene, but also to estimate the level of quantitative or semiquantitative retrospective exposure to benzene.

  17. Risk estimates of stochastic effects due to exposure to radiation - a stochastic harm index

    International Nuclear Information System (INIS)

    Gonen, Y.G.

    1980-01-01

    The effects of exposure to low level radiation on the survival probability and life expectancy were investigated. The 1977 vital statistics of Jewish males in Israel were used as a baseline, mainly the data on normalized survival probability and life expectation as functions of age. Assumed effects of exposure were superposed on these data and the net differences calculated. It was found that the realistic rate effects of exposure to radiation are generally less than calculated by multiplying the collective dose by the risk factor. The effects are strongly age-dependent, decreasing sharply with age at exposure. The assumed harm due to exposure can be more than offset by improvements in medical care and safety. (H.K.)

  18. Estimation of effective dose to public from external exposure to natural background radiation in saudi arabia

    International Nuclear Information System (INIS)

    Khalid, A. A.

    2003-01-01

    The effective dose values in sixteen cities in Saudi Arabia due to external exposure to natural radiation were evaluated. These doses are based on natural background components including external exposure to terrestrial radiation and cosmic rays. The importance of evaluating the effective dose to the public due to external exposure to natural background radiation lies in its epidemiological and dosimetric importance and in forming a basis for the assessment of the level of radioactive contamination or pollution in the environment in the future. The exposure to terrestrial radiation was measured using thermoluminescent dosimeters (TLD). The exposure from cosmic radiation was determined using empirical correlation. The values evaluated for the total annual effective dose in all cities were within the world average values. The highest total annual effective dose measured in Al-Khamis city was 802 μSv/y, as compared to 305 μSv/y in Dammam city, which was considered the lowest value

  19. Radiation exposure profile and dose estimates to flyers en route Frankfurt to Mumbai

    International Nuclear Information System (INIS)

    Rao, D.D.; Hegde, A.G.

    2010-01-01

    The earth is continuously bombarded by the high energy radiation (galactic radiation) from solar system commonly known as cosmic radiation. Intensity of cosmic ray radiation exposures change with altitude and increases rapidly with the increase in altitude from the earth. Passenger and cargo flights fly at different altitudes and therefore the crew and passengers are exposed to radiation levels significantly higher than the average background levels on the earth. A typical commercial jet aircraft fly at an altitude of 30,000 - 40,000 feet (9-12 km) and at these heights radiation exposure rates increase by about 100 times from the background levels. European countries have guidelines and suggestions on radiation exposure to air crew members in sectors that may potentially expose them to levels exceeding 1 mSv per annum. The paper details the radiation exposure profile recorded in Frankfurt-Dubai-Mumbai sector and evaluation of average radiation exposure received by the flyers and air crew members

  20. Evaluating methods for estimating space-time paths of individuals in calculating long-term personal exposure to air pollution

    Science.gov (United States)

    Schmitz, Oliver; Soenario, Ivan; Vaartjes, Ilonca; Strak, Maciek; Hoek, Gerard; Brunekreef, Bert; Dijst, Martin; Karssenberg, Derek

    2016-04-01

    Air pollution is one of the major concerns for human health. Associations between air pollution and health are often calculated using long-term (i.e. years to decades) information on personal exposure for each individual in a cohort. Personal exposure is the air pollution aggregated along the space-time path visited by an individual. As air pollution may vary considerably in space and time, for instance due to motorised traffic, the estimation of the spatio-temporal location of a persons' space-time path is important to identify the personal exposure. However, long term exposure is mostly calculated using the air pollution concentration at the x, y location of someone's home which does not consider that individuals are mobile (commuting, recreation, relocation). This assumption is often made as it is a major challenge to estimate space-time paths for all individuals in large cohorts, mostly because limited information on mobility of individuals is available. We address this issue by evaluating multiple approaches for the calculation of space-time paths, thereby estimating the personal exposure along these space-time paths with hyper resolution air pollution maps at national scale. This allows us to evaluate the effect of the space-time path and resulting personal exposure. Air pollution (e.g. NO2, PM10) was mapped for the entire Netherlands at a resolution of 5×5 m2 using the land use regression models developed in the European Study of Cohorts for Air Pollution Effects (ESCAPE, http://escapeproject.eu/) and the open source software PCRaster (http://www.pcraster.eu). The models use predictor variables like population density, land use, and traffic related data sets, and are able to model spatial variation and within-city variability of annual average concentration values. We approximated space-time paths for all individuals in a cohort using various aggregations, including those representing space-time paths as the outline of a persons' home or associated parcel

  1. Study of the uncertainty in estimation of the exposure of non-human biota to ionising radiation.

    Science.gov (United States)

    Avila, R; Beresford, N A; Agüero, A; Broed, R; Brown, J; Iospje, M; Robles, B; Suañez, A

    2004-12-01

    Uncertainty in estimations of the exposure of non-human biota to ionising radiation may arise from a number of sources including values of the model parameters, empirical data, measurement errors and biases in the sampling. The significance of the overall uncertainty of an exposure assessment will depend on how the estimated dose compares with reference doses used for risk characterisation. In this paper, we present the results of a study of the uncertainty in estimation of the exposure of non-human biota using some of the models and parameters recommended in the FASSET methodology. The study was carried out for semi-natural terrestrial, agricultural and marine ecosystems, and for four radionuclides (137Cs, 239Pu, 129I and 237Np). The parameters of the radionuclide transfer models showed the highest sensitivity and contributed the most to the uncertainty in the predictions of doses to biota. The most important ones were related to the bioavailability and mobility of radionuclides in the environment, for example soil-to-plant transfer factors, the bioaccumulation factors for marine biota and the gut uptake fraction for terrestrial mammals. In contrast, the dose conversion coefficients showed low sensitivity and contributed little to the overall uncertainty. Radiobiological effectiveness contributed to the overall uncertainty of the dose estimations for alpha emitters although to a lesser degree than a number of transfer model parameters.

  2. Application of a stratified random sampling technique to the estimation and minimization of respirable quartz exposure to underground miners

    International Nuclear Information System (INIS)

    Makepeace, C.E.; Horvath, F.J.; Stocker, H.

    1981-11-01

    The aim of a stratified random sampling plan is to provide the best estimate (in the absence of full-shift personal gravimetric sampling) of personal exposure to respirable quartz among underground miners. One also gains information of the exposure distribution of all the miners at the same time. Three variables (or strata) are considered in the present scheme: locations, occupations and times of sampling. Random sampling within each stratum ensures that each location, occupation and time of sampling has equal opportunity of being selected without bias. Following implementation of the plan and analysis of collected data, one can determine the individual exposures and the mean. This information can then be used to identify those groups whose exposure contributes significantly to the collective exposure. In turn, this identification, along with other considerations, allows the mine operator to carry out a cost-benefit optimization and eventual implementation of engineering controls for these groups. This optimization and engineering control procedure, together with the random sampling plan, can then be used in an iterative manner to minimize the mean value of the distribution and collective exposures

  3. Risk of heart failure in survivors of Hodgkin lymphoma: effects of cardiac exposure to radiation and anthracyclines.

    Science.gov (United States)

    van Nimwegen, Frederika A; Ntentas, Georgios; Darby, Sarah C; Schaapveld, Michael; Hauptmann, Michael; Lugtenburg, Pieternella J; Janus, Cecile P M; Daniels, Laurien; van Leeuwen, Flora E; Cutter, David J; Aleman, Berthe M P

    2017-04-20

    Hodgkin lymphoma (HL) survivors treated with radiotherapy and/or chemotherapy are known to have increased risks of heart failure (HF), but a radiation dose-response relationship has not previously been derived. A case-control study, nested in a cohort of 2617 five-year survivors of HL diagnosed before age 51 years during 1965 to 1995, was conducted. Cases (n = 91) had moderate or severe HF as their first cardiovascular diagnosis. Controls (n = 278) were matched to cases on age, sex, and HL diagnosis date. Treatment and follow-up information were abstracted from medical records. Mean heart doses and mean left ventricular doses (MLVD) were estimated by reconstruction of individual treatments on representative computed tomography datasets. Average MLVD was 16.7 Gy for cases and 13.8 Gy for controls ( P difference = .003). HF rate increased with MLVD: relative to 0 Gy, HF rates following MVLD of 1-15, 16-20, 21-25, and ≥26 Gy were 1.27, 1.65, 3.84, and 4.39, respectively ( P trend < .001). Anthracycline-containing chemotherapy increased HF rate by a factor of 2.83 (95% CI: 1.43-5.59), and there was no significant interaction with MLVD ( P interaction = .09). Twenty-five-year cumulative risks of HF following MLVDs of 0-15 Gy, 16-20 Gy, and ≥21 Gy were 4.4%, 6.2%, and 13.3%, respectively, in patients treated without anthracycline-containing chemotherapy, and 11.2%, 15.9%, and 32.9%, respectively, in patients treated with anthracyclines. We have derived quantitative estimates of HF risk in patients treated for HL following radiotherapy with or without anthracycline-containing chemotherapy. Our results enable estimation of HF risk for patients before treatment, during radiotherapy planning, and during follow-up. © 2017 by The American Society of Hematology.

  4. An Estimation of the Whole-of-Life Noise Exposure of Adolescent and Young Adult Australians with Hearing Impairment.

    Science.gov (United States)

    Carter, Lyndal; Black, Deborah; Bundy, Anita; Williams, Warwick

    2016-10-01

    Since amplified music gained widespread popularity, there has been community concern that leisure-noise exposure may cause hearing loss in adolescents and young adults who would otherwise be free from hearing impairment. Repeated exposure to personal stereo players and music events (e.g., nightclubbing, rock concerts, and music festivals) are of particular concern. The same attention has not been paid to leisure-noise exposure risks for young people with hearing impairment (either present from birth or acquired before adulthood). This article reports on the analysis of a subset of data (leisure participation measures) collected during a large, two-phase study of the hearing health, attitudes, and behaviors of 11- to 35-yr-old Australians conducted by the National Acoustic Laboratories (n = 1,667 hearing threshold level datasets analyzed). The overall aim of the two-phase study was to determine whether a relationship between leisure-noise exposure and hearing loss exists. In the current study, the leisure activity profiles and accumulated ("whole-of-life") noise exposures of young people with (1) hearing impairment and (2) with normal hearing were compared. Cross-sectional cohort study. Hearing impaired (HI) group, n = 125; normal (nonimpaired) hearing (NH) group, n = 296, analyzed in two age-based subsets: adolescents (13- to 17-yr-olds) and young adults (18- to 24-yr-olds). Participant survey. The χ² test was used to identify systematic differences between the leisure profiles and exposure estimates of the HI and NH groups. Whole-of-life noise exposure was estimated by adapting techniques described in ISO 1999. For adolescents, leisure profiles were similar for the two groups and few individuals exceeded the stated risk criterion. For young adults, participation was significantly lower for the HI group for 7 out of 18 leisure activities surveyed. Activity diversity and whole-of-life exposure were also significantly lower for the HI group young adults. A

  5. Developing a method for the retrospective estimation of radon exposure from in vivo measurements of 210Pb activity in bone

    International Nuclear Information System (INIS)

    McKenzie, R.J.; Johnston, P.N.

    1999-01-01

    Radon is a naturally occurring radioactive gas which has been linked to lung cancer in occupationally exposed uranium mine workers. Where monitoring of an individual's exposure to radon and radon progeny has not occurred or is incomplete, it may be possible to determine this exposure retrospectively by the measurement of the long lived decay product 210 Pb which accumulates in the bones of exposed individuals. This paper describes a method being developed at the whole body monitor (WBM) facility of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) to estimate the time integrated exposure to radon over a period of up to several decades from the in vivo measurements of 210 Pb activity in the knee of human subjects. Initial work has concentrated on characterising the WBM facility for this work using artificial bone phantoms. This project will serve as a test of the feasibility of the method before undertaking further studies on human subjects

  6. What are the elements required to improve exposure estimates in life cycle assessments?

    DEFF Research Database (Denmark)

    Ernstoff, Alexi; Rosenbaum, Ralph K.; Margni, Manuele

    2016-01-01

    human toxicity and ecosystem toxicity of chemicals posed by different product life cycle stages are characterized in the life cycle impact assessment (LCIA) phase. Exposure and effect quantification as part of LCIA toxicity characterization faces numerous challenges related to inventory analysis (e.......g. number and quantity of chemicals emitted), substance-specific modelling (e.g. organics, inorganics, nano-materials) in various environments and time horizons, human and ecosystem exposure quantification (e.g. exposed organisms and exposure pathways), and toxicity end-points (e.g. carcinogenicity...... chemical exposure and harmful effects. Thereby, we structure this study of key elements identified as areas of elevated public, industrial, regulatory, and scientific concerns. We found the majority of missing elements are directly related to the definition of exposed populations (both ecosystems...

  7. ESTIMATED RATE OF FATAL AUTOMOBILE ACCIDENTS ATTRIBUTABLE TO ACUTE SOLVENT EXPOSURE AT LOW INHALED CONCENTRATIONS

    Science.gov (United States)

    Acute solvent exposures may contribute to automobile accidents because they increase reaction time and decrease attention, in addition to impairing other behaviors. These effects resemble those of ethanol consumption, both with respect to behavioral effects and neurological mecha...

  8. ADVISORY ON UPDATED METHODOLOGY FOR ESTIMATING CANCER RISKS FROM EXPOSURE TO IONIZING RADIATION

    Science.gov (United States)

    The National Academy of Sciences (NAS) published the Biological Effects of Ionizing Radiation (BEIR) committee's report (BEIR VII) on risks from ionizing radiation exposures in 2006. The Committee analyzed the most recent epidemiology from the important exposed cohorts and factor...

  9. Advective and diffusive dermal processes for estimating terrestrial amphibian pesticide exposure

    Science.gov (United States)

    Background/Question/Methods Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Historically, evaluation of pesticide risk to both amphibians and reptiles has been achieved by comparing ingestion and inhalat...

  10. Children's phthalate intakes and resultant cumulative exposures estimated from urine compared with estimates from dust ingestion, inhalation and dermal absorption in their homes and daycare centers.

    Directory of Open Access Journals (Sweden)

    Gabriel Bekö

    Full Text Available Total daily intakes of diethyl phthalate (DEP, di(n-butyl phthalate (DnBP, di(isobutyl phthalate (DiBP, butyl benzyl phthalate (BBzP and di(2-ethylhexyl phthalate (DEHP were calculated from phthalate metabolite levels measured in the urine of 431 Danish children between 3 and 6 years of age. For each child the intake attributable to exposures in the indoor environment via dust ingestion, inhalation and dermal absorption were estimated from the phthalate levels in the dust collected from the child's home and daycare center. Based on the urine samples, DEHP had the highest total daily intake (median: 4.42 µg/d/kg-bw and BBzP the lowest (median: 0.49 µg/d/kg-bw. For DEP, DnBP and DiBP, exposures to air and dust in the indoor environment accounted for approximately 100%, 15% and 50% of the total intake, respectively, with dermal absorption from the gas-phase being the major exposure pathway. More than 90% of the total intake of BBzP and DEHP came from sources other than indoor air and dust. Daily intake of DnBP and DiBP from all exposure pathways, based on levels of metabolites in urine samples, exceeded the Tolerable Daily Intake (TDI for 22 and 23 children, respectively. Indoor exposures resulted in an average daily DiBP intake that exceeded the TDI for 14 children. Using the concept of relative cumulative Tolerable Daily Intake (TDI(cum, which is applicable for phthalates that have established TDIs based on the same health endpoint, we examined the cumulative total exposure to DnBP, DiBP and DEHP from all pathways; it exceeded the tolerable levels for 30% of the children. From the three indoor pathways alone, several children had a cumulative intake that exceeded TDI(cum. Exposures to phthalates present in the air and dust indoors meaningfully contribute to a child's total intake of certain phthalates. Such exposures, by themselves, may lead to intakes exceeding current limit values.

  11. Children’s Phthalate Intakes and Resultant Cumulative Exposures Estimated from Urine Compared with Estimates from Dust Ingestion, Inhalation and Dermal Absorption in Their Homes and Daycare Centers

    Science.gov (United States)

    Bekö, Gabriel; Weschler, Charles J.; Langer, Sarka; Callesen, Michael; Toftum, Jørn; Clausen, Geo

    2013-01-01

    Total daily intakes of diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) were calculated from phthalate metabolite levels measured in the urine of 431 Danish children between 3 and 6 years of age. For each child the intake attributable to exposures in the indoor environment via dust ingestion, inhalation and dermal absorption were estimated from the phthalate levels in the dust collected from the child’s home and daycare center. Based on the urine samples, DEHP had the highest total daily intake (median: 4.42 µg/d/kg-bw) and BBzP the lowest (median: 0.49 µg/d/kg-bw). For DEP, DnBP and DiBP, exposures to air and dust in the indoor environment accounted for approximately 100%, 15% and 50% of the total intake, respectively, with dermal absorption from the gas-phase being the major exposure pathway. More than 90% of the total intake of BBzP and DEHP came from sources other than indoor air and dust. Daily intake of DnBP and DiBP from all exposure pathways, based on levels of metabolites in urine samples, exceeded the Tolerable Daily Intake (TDI) for 22 and 23 children, respectively. Indoor exposures resulted in an average daily DiBP intake that exceeded the TDI for 14 children. Using the concept of relative cumulative Tolerable Daily Intake (TDIcum), which is applicable for phthalates that have established TDIs based on the same health endpoint, we examined the cumulative total exposure to DnBP, DiBP and DEHP from all pathways; it exceeded the tolerable levels for 30% of the children. From the three indoor pathways alone, several children had a cumulative intake that exceeded TDIcum. Exposures to phthalates present in the air and dust indoors meaningfully contribute to a child’s total intake of certain phthalates. Such exposures, by themselves, may lead to intakes exceeding current limit values. PMID:23626820

  12. Childhood lead exposure in France: benefit estimation and partial cost-benefit analysis of lead hazard control

    Directory of Open Access Journals (Sweden)

    Zmirou-Navier Denis

    2011-05-01

    Full Text Available Abstract Background Lead exposure remains a public health concern due to its serious adverse effects, such as cognitive and behavioral impairment: children younger than six years of age being the most vulnerable population. In Europe, the lead-related economic impacts have not been examined in detail. We estimate the annual costs in France due to childhood exposure and, through a cost benefit analysis (CBA, aim to assess the expected social and economic benefits of exposure abatement. Methods Monetary benefits were assessed in terms of avoided national costs. We used results from a 2008 survey on blood-lead (B-Pb concentrations in French children aged one to six years old. Given the absence of a threshold concentration being established, we performed a sensitivity analysis assuming different hypothetical threshold values for toxicity above 15 μg/L, 24 μg/L and 100 μg/L. Adverse health outcomes of lead exposure were translated into social burden and economic costs based on literature data from literature. Direct health benefits, social benefits and intangible avoided costs were included. Costs of pollutant exposure control were partially estimated in regard to homes lead-based paint decontamination, investments aiming at reducing industrial lead emissions and removal of all lead drinking water pipes. Results The following overall annual benefits for the three hypothetical thresholds values in 2008 are: €22.72 billion, €10.72 billion and €0.44 billion, respectively. Costs from abatement ranged from €0.9 billion to 2.95 billion/year. Finally, from a partial CBA of lead control in soils and dust the estimates of total net benefits were € 3.78 billion, € 1.88 billion and €0.25 billion respectively for the three hypothesized B-Pb effect values. Conclusions Prevention of childhood lead exposure has a high social benefit, due to reduction of B-Pb concentrations to levels below 15 μg/L or 24 μg/L, respectively. Reducing only exposures

  13. Cardiac rehabilitation

    Science.gov (United States)

    ... rehab; Heart failure - cardiac rehab References Anderson L, Taylor RS. Cardiac rehabilitation for people with heart disease: ... of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed ...

  14. Estimation of diastolic filling pressure with cardiac CT in comparison with echocardiography using tissue doppler imaging: Determination of optimal CT reconstruction parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Sun; Suh, Jon; Lee, Heon [Soonchunhyang University Hospital Bucheon, Bucheon (Korea, Republic of); Lee, Bora [Dept. of Biostatistics, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of); Lee, Soo Jeong [Terarecon Korea, Seoul (Korea, Republic of); Jou, Sung Shick [Dept. of Radiology, Soonchunhyang University Hospital Cheonan, Cheonan (Korea, Republic of); Lim, Hyun Kyung [Dept. of Radiology, Soonchunhyang University Hospital Seoul, Seoul (Korea, Republic of)

    2017-08-01

    To determine the optimal CT image reconstruction parameters for the measurement of early transmitral peak velocity (E), early peak mitral septal tissue velocity (E′), and E / E′. Forty-six patients underwent simultaneous cardiac CT and echocardiography on the same day. Four CT datasets were reconstructed with a slice thickness/interval of 0.9/0.9 mm or 3/3 mm at 10 (10% RR-interval) or 20 (5% RR-interval) RR-intervals. The E was calculated by dividing the peak transmitral flow (mL/s) by the corresponding mitral valve area (cm{sup 2}). E′ was calculated from the changes in the left ventricular length per cardiac phase. E / E′ was then estimated and compared with that from echocardiography. For assessment of E / E′, CT and echocardiography were more strongly correlated (p < 0.05) with a slice thickness of 0.9 mm and 5% RR-interval (r = 0.77) than with 3 mm or 10% RR-interval. The diagnostic accuracy of predicting elevated filling pressure (E / E′ ≥ 13, n = 14) was better with a slice thickness of 0.9 mm and 5% RR-interval (87.0%) than with 0.9 mm and 10% RR-interval (71.7%) (p = 0.123) and significantly higher than that with a slice thickness of 3 mm with 5% (67.4%) and 10% RR-interval (63.0%), (p < 0.05), respectively. Data reconstruction with a slice thickness of 0.9 mm at 5% RR-interval is superior to that with a slice thickness of 3 mm or 10% RR-interval in terms of the correlation of E / E′ between CT and echocardiography. Thin slices and frequent sampling also allow for more accurate prediction of elevated filling pressure.

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  16. The Diesel Exhaust in Miners Study: IV. Estimating historical exposures to diesel exhaust in underground non-metal mining facilities.

    Science.gov (United States)

    Vermeulen, Roel; Coble, Joseph B; Lubin, Jay H; Portengen, Lützen; Blair, Aaron; Attfield, Michael D; Silverman, Debra T; Stewart, Patricia A

    2010-10-01

    We developed quantitative estimates of historical exposures to respirable elemental carbon (REC) for an epidemiologic study of mortality, including lung cancer, among diesel-exposed miners at eight non-metal mining facilities [the Diesel Exhaust in Miners Study (DEMS)]. Because there were no historical measurements of diesel exhaust (DE), historical REC (a component of DE) levels were estimated based on REC data from monitoring surveys conducted in 1998-2001 as part of the DEMS investigation. These values were adjusted for underground workers by carbon monoxide (CO) concentration trends in the mines derived from models of historical CO (another DE component) measurements and DE determinants such as engine horsepower (HP; 1 HP = 0.746 kW) and mine ventilation. CO was chosen to estimate historical changes because it was the most frequently measured DE component in our study facilities and it was found to correlate with REC exposure. Databases were constructed by facility and year with air sampling data and with information on the total rate of airflow exhausted from the underground operations in cubic feet per minute (CFM) (1 CFM = 0.0283 m³ min⁻¹), HP of the diesel equipment in use (ADJ HP), and other possible determinants. The ADJ HP purchased after 1990 (ADJ HP₁₉₉₀(+)) was also included to account for lower emissions from newer, cleaner engines. Facility-specific CO levels, relative to those in the DEMS survey year for each year back to the start of dieselization (1947-1967 depending on facility), were predicted based on models of observed CO concentrations and log-transformed (Ln) ADJ HP/CFM and Ln(ADJ HP₁₉₉₀(+)). The resulting temporal trends in relative CO levels were then multiplied by facility/department/job-specific REC estimates derived from the DEMS surveys personal measurements to obtain historical facility/department/job/year-specific REC exposure estimates. The facility-specific temporal trends of CO levels (and thus the REC

  17. Quantitative cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Thelen, M.; Dueber, C.; Wolff, P.; Erbel, R.; Hoffmann, T.

    1985-06-01

    The scope and limitations of quantitative cardiac CT have been evaluated in a series of experimental and clinical studies. The left ventricular muscle mass was estimated by computed tomography in 19 dogs (using volumetric methods, measurements in two axes and planes and reference volume). There was good correlation with anatomical findings. The enddiastolic volume of the left ventricle was estimated in 22 patients with cardiomyopathies; using angiography as a reference, CT led to systematic under-estimation. It is also shown that ECG-triggered magnetic resonance tomography results in improved visualisation and may be expected to improve measurements of cardiac morphology.

  18. An estimation of exposure from gaseous and volatile radioactive effluents released from EWA reactor between 1971 and 1975

    International Nuclear Information System (INIS)

    Filipiak, B.; Nowicki, K.

    1979-01-01

    The paper gives an estimation of radiation doses for individuals due to gaseous radioactive effluents released from EWA reactor between 1971 and 1975. The doses were estimated for three organs, three groups of people: adults, teenagers and children and for three of the most important exposure paths: the external radiation from a passing cloud, inhalation and from milk ingestion. The results of calculations indicate that the radiation doses received by individuals living in the vicinity of EWA reactor were much below the limit doses or those due to the background radiation. (author)

  19. High-throughput migration modelling for estimating exposure to chemicals in food packaging in screening and prioritization tools

    DEFF Research Database (Denmark)

    Ernstoff, Alexi S; Fantke, Peter; Huang, Lei

    2017-01-01

    Specialty software and simplified models are often used to estimate migration of potentially toxic chemicals from packaging into food. Current models, however, are not suitable for emerging applications in decision-support tools, e.g. in Life Cycle Assessment and risk-based screening and prioriti...... to uncertainty and dramatically decreased model performance (R2 = 0.4, Se = 1). In all, this study provides a rapid migration modelling approach to estimate exposure to chemicals in food packaging for emerging screening and prioritization approaches....

  20. Blending Multiple Nitrogen Dioxide Data Sources for Neighborhood Estimates of Long-Term Exposure for Health Research.

    Science.gov (United States)

    Hanigan, Ivan C; Williamson, Grant J; Knibbs, Luke D; Horsley, Joshua; Rolfe, Margaret I; Cope, Martin; Barnett, Adrian G; Cowie, Christine T; Heyworth, Jane S; Serre, Marc L; Jalaludin, Bin; Morgan, Geoffrey G

    2017-11-07

    Exposure to traffic related nitrogen dioxide (NO 2 ) air pollution is associated with adverse health outcomes. Average pollutant concentrations for fixed monitoring sites are often used to estimate exposures for health studies, however these can be imprecise due to difficulty and cost of spatial modeling at the resolution of neighborhoods (e.g., a scale of tens of meters) rather than at a coarse scale (around several kilometers). The objective of this study was to derive improved estimates of neighborhood NO 2 concentrations by blending measurements with modeled predictions in Sydney, Australia (a low pollution environment). We implemented the Bayesian maximum entropy approach to blend data with uncertainty defined using informative priors. We compiled NO 2 data from fixed-site monitors, chemical transport models, and satellite-based land use regression models to estimate neighborhood annual average NO 2 . The spatial model produced a posterior probability density function of estimated annual average concentrations that spanned an order of magnitude from 3 to 35 ppb. Validation using independent data showed improvement, with root mean squared error improvement of 6% compared with the land use regression model and 16% over the chemical transport model. These estimates will be used in studies of health effects and should minimize misclassification bias.

  1. Arsenic levels in wipe samples collected from play structures constructed with CCA-treated wood: Impact on exposure estimates

    Energy Technology Data Exchange (ETDEWEB)

    Barraj, Leila M. [Chemical Regulation and Food Safety, Exponent, Inc., Suite 1100, 1150 Connecticut Ave., NW, Washington, DC 20036 (United States)], E-mail: lbarraj@exponent.com; Scrafford, Carolyn G. [Chemical Regulation and Food Safety, Exponent, Inc., Suite 1100, 1150 Connecticut Ave., NW, Washington, DC 20036 (United States); Eaton, W. Cary [RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709 (United States); Rogers, Robert E.; Jeng, Chwen-Jyh [Toxcon Health Sciences Research Centre Inc., 9607 - 41 Avenue, Edmonton, Alberta, T6E 5X7 (Canada)

    2009-04-01

    Lumber treated with chromated copper arsenate (CCA) has been used in residential outdoor wood structures and playgrounds. The U.S. EPA has conducted a probabilistic assessment of children's exposure to arsenic from CCA-treated structures using the Stochastic Human Exposure and Dose Simulation model for the wood preservative scenario (SHEDS-Wood). The EPA assessment relied on data from an experimental study using adult volunteers and designed to measure arsenic in maximum hand and wipe loadings. Analyses using arsenic handloading data from a study of children playing on CCA-treated play structures in Edmonton, Canada, indicate that the maximum handloading values significantly overestimate the exposure that occurs during actual play. The objective of our paper is to assess whether the dislodgeable arsenic residues from structures in the Edmonton study are comparable to those observed in other studies and whether they support the conclusion that the values derived by EPA using modeled maximum loading values overestimate hand exposures. We compared dislodgeable arsenic residue data from structures in the playgrounds in the Edmonton study to levels observed in studies used in EPA's assessment. Our analysis showed that the dislodgeable arsenic levels in the Edmonton playground structures are similar to those in the studies used by EPA. Hence, the exposure estimates derived using the handloading data from children playing on CCA-treated structures are more representative of children's actual exposures than the overestimates derived by EPA using modeled maximum values. Handloading data from children playing on CCA-treated structures should be used to reduce the uncertainty of modeled estimates derived using the SHEDS-Wood model.

  2. Multiphysics and Thermal Response Models to Improve Accuracy of Local Temperature Estimation in Rat Cortex under Microwave Exposure

    Science.gov (United States)

    Kodera, Sachiko; Gomez-Tames, Jose; Hirata, Akimasa; Masuda, Hiroshi; Arima, Takuji; Watanabe, Soichi

    2017-01-01

    The rapid development of wireless technology has led to widespread concerns regarding adverse human health effects caused by exposure to electromagnetic fields. Temperature elevation in biological bodies is an important factor that can adversely affect health. A thermophysiological model is desired to quantify microwave (MW) induced temperature elevations. In this study, parameters related to thermophysiological responses for MW exposures were estimated using an electromagnetic-thermodynamics simulation technique. To the authors’ knowledge, this is the first study in which parameters related to regional cerebral blood flow in a rat model were extracted at a high degree of accuracy through experimental measurements for localized MW exposure at frequencies exceeding 6 GHz. The findings indicate that the improved modeling parameters yield computed results that match well with the measured quantities during and after exposure in rats. It is expected that the computational model will be helpful in estimating the temperature elevation in the rat brain at multiple observation points (that are difficult to measure simultaneously) and in explaining the physiological changes in the local cortex region. PMID:28358345

  3. Quantification of deaths attributed to air pollution in Sweden using estimated population exposure to nitrogen dioxide as indicator

    International Nuclear Information System (INIS)

    Forsberg, Bertil; Sjoeberg, Karin

    2005-08-01

    In the previous phase of this project a model was provided for quantifying the general population exposure to air pollution. From that work interpolated yearly mean concentrations of nitrogen dioxide were provided for the Swedish population. To be applied in the health impact assessment we selected an ecological study from Auckland, New Zealand, which reported a 13 % increase in non-accidental mortality (all ages) for 10 μg/m 3 increase in NO 2 . Based on official national data we assumed a baseline rate of 1,010 deaths per 100,000 persons and year at the population weighted mean level of approximately 10 μg NO 2 /m 3 . We then calculated the death rate and the yearly number of deaths expected at the population weighted mean exposure in each of four exposure classes above 10 μg/m 3 . Using the modelled levels of NO 2 as an indicator of air pollution levels from transportation and combustion, and calculating effects on mortality only above the yearly mean 10 μg/m 3 , we estimated excess exposure to result in 2,837 (95% CI 2400-3273) deaths per year. A recent paper presenting similar calculations estimated the local contribution to urban levels of PM in Sweden to result in around 1,800 deaths per year, but the authors questioned the use of risk coefficients for regional PM to assess the effect of local traffic pollutants. The new results obtained, using locally produced nitrogen dioxide as the basis for the risk assessment, resulted in an impact estimate 55 % higher than the published estimate based on PM

  4. Human cancer risk estimation for 1,3-butadiene: An assessment of personal exposure and different microenvironments.

    Science.gov (United States)

    Huy, Lai Nguyen; Lee, Shun Cheng; Zhang, Zhuozhi

    2018-03-01

    This study estimated the lifetime cancer risk (LCR) attributable to 1,3-butadiene (BD) personal exposure and to other microenvironments, including residential home, outdoor, in-office, in-vehicle, and dining. Detailed life expectancy by country (WHO), inhalation rate and body weight by gender reported by USEPA were used for the calculation, focusing on adult population (25≤Agepersonal exposure exceeded the USEPA benchmark of 1×10 -6 in many cities. For outdoor BD exposure, LCR estimations in 45 out of 175 cities/sites (sharing 26%) exceeded the USEPA benchmark. Out of the top 20 cities having high LCR estimations, developing countries contributed 19 cities, including 14, 3, 1, 1 cities in China, India, Chile, and Pakistan. One city in the United States was in the list due to the nearby industrial facilities. The LCR calculations for BD levels found in residential home, in-vehicle and dining microenvironments also exceeded 1×10 -6 in some cities, while LCR caused by in-office BD levels had the smallest risk. Four cities/regions were used for investigating source distributions to total LCR results because of their sufficient BD data. Home exposure contributed significantly to total LCR value (ranging 56% to 86%), followed by in-vehicle (4% to 38%) and dining (4 to 7%). Outdoor microenvironment shared highly in Tianjin with 6%, whereas in-office contributed from 2-3% for all cities. High LCR estimations found in developing countries highlighted the greater cancer risk caused by BD in other cities without available measurement data. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Evaluation of the Webler-Brown model for estimating tetrachloroethylene exposure from vinyl-lined asbestos-cement pipes

    Directory of Open Access Journals (Sweden)

    Heeren Timothy C

    2008-06-01

    Full Text Available Abstract Background From May 1968 through March 1980, vinyl-lined asbestos-cement (VL/AC water distribution pipes were installed in New England to avoid taste and odor problems associated with asbestos-cement pipes. The vinyl resin was applied to the inner pipe surface in a solution of tetrachloroethylene (perchloroethylene, PCE. Substantial amounts of PCE remained in the liner and subsequently leached into public drinking water supplies. Methods Once aware of the leaching problem and prior to remediation (April-November 1980, Massachusetts regulators collected drinking water samples from VL/AC pipes to determine the extent and severity of the PCE contamination. This study compares newly obtained historical records of PCE concentrations in water samples (n = 88 with concentrations estimated using an exposure model employed in epidemiologic studies on the cancer risk associated with PCE-contaminated drinking water. The exposure model was developed by Webler and Brown to estimate the mass of PCE delivered to subjects' residences. Results The mean and median measured PCE concentrations in the water samples were 66 and 0.5 μg/L, respectively, and the range extended from non-detectable to 2432 μg/L. The model-generated concentration estimates and water sample concentrations were moderately correlated (Spearman rank correlation coefficient = 0.48, p Conclusion PCE concentration estimates generated using the Webler-Brown model were moderately correlated with measured water concentrations. The present analysis suggests that the exposure assessment process used in prior epidemiological studies could be improved with more accurate characterization of water flow. This study illustrates one method of validating an exposure model in an epidemiological study when historical measurements are not available.

  6. An evaluation of data-driven motion estimation in comparison to the usage of external-surrogates in cardiac SPECT imaging

    International Nuclear Information System (INIS)

    Mukherjee, Joyeeta Mitra; Johnson, Karen L; Pretorius, P Hendrik; King, Michael A; Hutton, Brian F

    2013-01-01

    Motion estimation methods in single photon emission computed tomography (SPECT) can be classified into methods which depend on just the emission data (data-driven), or those that use some other source of information such as an external surrogate. The surrogate-based methods estimate the motion exhibited externally which may not correlate exactly with the movement of organs inside the body. The accuracy of data-driven strategies on the other hand is affected by the type and timing of motion occurrence during acquisition, the source distribution, and various degrading factors such as attenuation, scatter, and system spatial resolution. The goal of this paper is to investigate the performance of two data-driven motion estimation schemes based on the rigid-body registration of projections of motion-transformed source distributions to the acquired projection data for cardiac SPECT studies. Comparison is also made of six intensity based registration metrics to an external surrogate-based method. In the data-driven schemes, a partially reconstructed heart is used as the initial source distribution. The partially-reconstructed heart has inaccuracies due to limited angle artifacts resulting from using only a part of the SPECT projections acquired while the patient maintained the same pose. The performance of different cost functions in quantifying consistency with the SPECT projection data in the data-driven schemes was compared for clinically realistic patient motion occurring as discrete pose changes, one or two times during acquisition. The six intensity-based metrics studied were mean-squared difference, mutual information, normalized mutual information (NMI), pattern intensity (PI), normalized cross-correlation and entropy of the difference. Quantitative and qualitative analysis of the performance is reported using Monte-Carlo simulations of a realistic heart phantom including degradation factors such as attenuation, scatter and system spatial resolution. Further the

  7. A case of lung cancer in a miner - An estimation of radon exposure and discussion of probable causes

    International Nuclear Information System (INIS)

    Snihs, J.O.; Walinder, Gunnar.

    1977-01-01

    One particular lung cancer case which was brought before the National Swedish Social Insurance Board as a possible case of industrial injury due to exposure to radon is described. The man concerned had worked in two mines during the period 1917-1944 and he was found to be suffering from lung cancer in 1961 when he was 69 years of age. He had been a moderate smoker for the previous 20 years, he had a healed lung tuberculosis and confirmed silicosis in stage 1. The mines in which he worked have been out of use for many years and they have bot been accessible for measurements of radon concentrations. The estimation of the radon concentrations is discussed on the basis of experience of the causes of radon occurrence in other mines with regard to their geology, ventilation and depth and the extent to which mine water was present. The estimated exposure was 600 WLM. With the given conditions there is a discussion on the partial and combined probabilities of lung cancer in the above case taking into account the type of lung cancer, the estimated exposure to radon and his smoking, silicosis, tuberculosis and age

  8. Estimating the mercury exposure dose in a population of migratory bird hunters in the St. Lawrence River region, Quebec, Canada

    International Nuclear Information System (INIS)

    Duchesne, J.-F.; Levesque, B.; Gauvin, Denis; Braune, Birgit; Gingras, Suzanne; Dewailly, E.

    2004-01-01

    St. Lawrence River hunters (Quebec, Canada) are exposed to the pollutants, especially mercury, that contaminate birds and fish. However, the health risks of this have remained unclear because of a lack of information about the hunters' duck, geese, and sportfish consumption habits. A nutritional survey was set up to characterize waterfowl and sportfish consumption in St. Lawrence River duck hunters and to estimate their daily exposure to mercury. During the winter of 2000, 512 hunters selected from the Canadian Wildlife Service database completed a self-administered questionnaire. Daily exposure to contaminants was measured using data from the Canadian Wildlife Service (waterfowl) and available data on St. Lawrence River sportfish. The annual average consumption was 7.5 meals of ducks and geese and 8.7 meals of sportfish. The daily exposure to mercury related to waterfowl consumption was below the Canadian tolerable daily intake (TDI) of 0.47 μg/kg body wt/day for all participants. The daily mercury intake associated with fish consumption was greater than the TDI in 2 duck hunters. The daily exposure to mercury was higher than the TDI in 4 participants when both waterfowl and fish consumption were combined. Our results suggest that fish consumption (especially freshwater fish) represents the main source of exposure to pollutants in duck hunters

  9. Air pollution exposure estimation using dispersion modelling and continuous monitoring data in a prospective birth cohort study in the Netherlands

    Directory of Open Access Journals (Sweden)

    Van den Hooven Edith H

    2012-02-01

    Full Text Available Abstract Previous studies suggest that pregnant women and children are particularly vulnerable to the adverse effects of air pollution. A prospective cohort study in pregnant women and their children enables identification of the specific effects and critical periods. This paper describes the design of air pollution exposure assessment for participants of the Generation R Study, a population-based prospective cohort study from early pregnancy onwards in 9778 women in the Netherlands. Individual exposures to PM10 and NO2 levels at the home address were estimated for mothers and children, using a combination of advanced dispersion modelling and continuous monitoring data, taking into account the spatial and temporal variation in air pollution concentrations. Full residential history was considered. We observed substantial spatial and temporal variation in air pollution exposure levels. The Generation R Study provides unique possibilities to examine effects of short- and long-term air pollution exposure on various maternal and childhood outcomes and to identify potential critical windows of exposure.

  10. Comparison of particulate matter exposure estimates in young children from personal sampling equipment and a robotic sampler.

    Science.gov (United States)

    Sagona, Jessica A; Shalat, Stuart L; Wang, Zuocheng; Ramagopal, Maya; Black, Kathleen; Hernandez, Marta; Mainelis, Gediminas

    2017-05-01

    Accurate characterization of particulate matter (PM) exposure in young children is difficult, because personal samplers are often too heavy, bulky or impractical to be used. The Pretoddler Inhalable Particulate Environmental Robotic (PIPER) sampler was developed to help address this problem. In this study, we measured inhalable PM exposures in 2-year-olds via a lightweight personal sampler worn in a small backpack and evaluated the use of a robotic sampler with an identical sampling train for estimating PM exposure in this age group. PM mass concentrations measured by the personal sampler ranged from 100 to almost 1,200 μg/m 3 , with a median value of 331 μg/m 3 . PM concentrations measured by PIPER were considerably lower, ranging from 14 to 513 μg/m 3 with a median value of 56 μg/m 3 . Floor cleaning habits and activity patterns of the 2-year-olds varied widely by home; vigorous play and recent floor cleaning were most associated with higher personal exposure. Our findings highlight the need for additional characterization of children's activity patterns and their effect on personal exposures.

  11. Wide beam reconstruction for half-dose or half-time cardiac gated SPECT acquisitions: optimization of resources and reduction in radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Marcassa, Claudio [S. Maugeri Fnd, IRCCS, Scientific Institute of Veruno, Cardiology Department (Italy); Campini, Riccardo; Zoccarato, Orazio; Calza, Paolo [S. Maugeri Fnd, IRCCS, Scientific Institute of Veruno, Nuclear Medicine Department (Italy)

    2011-03-15

    A new iterative reconstruction algorithm (WBR trademark) has been recently proposed for cardiac single photon emission computed tomography (SPECT). The WBR trademark technology is designed to reduce noise, improving lesion identification without affecting the image resolution, allowing SPECT studies with reduced count statistic. This allows for either half-time (HT) or half-dose (HD) cardiac SPECT, with image quality and quantitative data comparable to standard-time (ST) or standard-dose (SD) SPECT. Few data exist on the comparison between conventional filtered backprojection (FBP) and this new algorithm in a clinical setting. The aim of this study was to compare the performance of FBP and WBR trademark. Phantoms studies were performed to compare spatial resolution and contrast recovery with FBP, ordered subset expectation maximization (OSEM) and WBR trademark. A group of 92 patients, with different cardiac pathology, scheduled for a stress-rest SPECT were studied: 52 patients (group A) were injected with a SD of tracer and underwent both ST and HT SPECT; 40 patients (group B) were injected with a half dose of tracer and underwent ST SPECT and immediately after an additional SPECT at double time/projection (DT), to compensate for the low count statistic. A 2-day {sup 99m}Tc-sestamibi protocol was used in all patients. SD/ST and HD/DT SPECT were reconstructed with a conventional FBP; SD/HT and HD/ST SPECT were reconstructed with WBR trademark. The summed stress score (SSS) and summed rest score (SRS) were calculated; the left ventricular ejection fraction (LVEF) was automatically derived. In group A (SD), no significant differences were observed between ST FBP SPECT and HT WBR trademark in SSS (11.1 and 11.7, respectively) and SRS (9.4 and 10.3, respectively, NS). LVEF on rest acquisitions was also comparable (50% on ST SPECT and 49% on HT SPECT, NS); LVEF on post-stress studies in HT SPECT (46%) was lower than ST SPECT (50%), although not statistically significant

  12. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables

  13. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.

  14. Mean total arsenic concentrations in chicken 1989-2000 and estimated exposures for consumers of chicken.

    OpenAIRE

    Lasky, Tamar; Sun, Wenyu; Kadry, Abdel; Hoffman, Michael K

    2004-01-01

    The purpose of this study was to estimate mean concentrations of total arsenic in chicken liver tissue and then estimate total and inorganic arsenic ingested by humans through chicken consumption. We used national monitoring data from the Food Safety and Inspection Service National Residue Program to estimate mean arsenic concentrations for 1994-2000. Incorporating assumptions about the concentrations of arsenic in liver and muscle tissues as well as the proportions of inorganic and organic a...

  15. A study of health effect estimates using competing methods to model personal exposures to ambient PM2.5.

    Science.gov (United States)

    Strand, Matthew; Hopke, Philip K; Zhao, Weixiang; Vedal, Sverre; Gelfand, Erwin; Rabinovitch, Nathan

    2007-09-01

    Various methods have been developed recently to estimate personal exposures to ambient particulate matter less than 2.5 microm in diameter (PM2.5) using fixed outdoor monitors as well as personal exposure monitors. One class of estimators involves extrapolating values using ambient-source components of PM2.5, such as sulfate and iron. A key step in extrapolating these values is to correct for differences in infiltration characteristics of the component used in extrapolation (such as sulfate within PM2.5) and PM2.5. When this is not done, resulting health effect estimates will be biased. Another class of approaches involves factor analysis methods such as positive matrix factorization (PMF). Using either an extrapolation or a factor analysis method in conjunction with regression calibration allows one to estimate the direct effects of ambient PM2.5 on health, eliminating bias caused by using fixed outdoor monitors and estimated personal ambient PM2.5 concentrations. Several forms of the extrapolation method are defined, including some new ones. Health effect estimates that result from the use of these methods are compared with those from an expanded PMF analysis using data collected from a health study of asthmatic children conducted in Denver, Colorado. Examining differences in health effect estimates among the various methods using a measure of lung function (forced expiratory volume in 1 s) as the health indicator demonstrated the importance of the correction factor(s) in the extrapolation methods and that PMF yielded results comparable with the extrapolation methods that incorporated correction factors.

  16. Short term effects of particle exposure on hospital admissions in the Mid-Atlantic states: a population estimate.

    Directory of Open Access Journals (Sweden)

    Itai Kloog

    Full Text Available Many studies report significant associations between PM(2.5 (particulate matter <2.5 micrometers and hospital admissions. These studies mostly rely on a limited number of monitors which introduces exposure error, and excludes rural and suburban populations from locations where monitors are not available, reducing generalizability and potentially creating selection bias.Using prediction models developed by our group, daily PM(2.5 exposure was estimated across the Mid-Atlantic (Washington D.C., and the states of Delaware, Maryland, New Jersey, Pennsylvania, Virginia, New York and West Virginia. We then investigated the short-term effects of PM(2.5exposures on emergency hospital admissions of the elderly in the Mid-Atlantic region.We performed case-crossover analysis for each admission type, matching on day of the week, month and year and defined the hazard period as lag01 (a moving average of day of admission exposure and previous day exposure.We observed associations between short-term exposure to PM(2.5 and hospitalization for all outcomes examined. For example, for every 10-µg/m(3 increase in short-term PM(2.5 there was a 2.2% increase in respiratory diseases admissions (95% CI = 1.9 to 2.6, and a 0.78% increase in cardiovascular disease (CVD admission rate (95% CI = 0.5 to 1.0. We found differences in risk for CVD admissions between people living in rural and urban areas. For every10-µg/m(3 increase in PM(2.5 exposure in the 'rural' group there was a 1.0% increase (95% CI = 0.6 to 1.5, while for the 'urban' group the increase was 0.7% (95% CI = 0.4 to 1.0.Our findings showed that PM(2.5 exposure was associated with hospital admissions for all respiratory, cardio vascular disease, stroke, ischemic heart disease and chronic obstructive pulmonary disease admissions. In addition, we demonstrate that our AOD (Aerosol Optical Depth based exposure models can be successfully applied to epidemiological studies investigating the health

  17. Estimated dose rates to members of the public from external exposure to patients with {sup 131}I thyroid treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dewji, S., E-mail: dewjisa@ornl.gov; Bellamy, M.; Leggett, R.; Eckerman, K. [Oak Ridge National Laboratory, 1 Bethel Valley Road, MS-6335, Oak Ridge, Tennessee 37831 (United States); Hertel, N. [Oak Ridge National Laboratory, 1 Bethel Valley Road, MS-6335, Oak Ridge, Tennessee 37831 and Georgia Institute of Technology, 770 State Street, Atlanta, Georgia 30332-0745 (United States); Sherbini, S.; Saba, M. [United States Nuclear Regulatory Commission, Washington, DC 20555-0001 (United States)

    2015-04-15

    Purpose: Estimated dose rates that may result from exposure to patients who had been administered iodine-131 ({sup 131}I) 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 {sup 131}I. Methods: Dose rates were estimated for members of the public potentially exposed to external irradiation from patients recently treated with {sup 131}I. Tissue attenuation and iodine biokinetics were considered in the patient in a larger 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 {sup 131}I 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 {sup 131}I in the patient assumed a single voiding of urinary bladder contents that occurred during the trip at 2, 4, or 8 h after {sup 131}I 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

  18. Estimated dose rates to members of the public from external exposure to patients with 131I thyroid treatment

    International Nuclear Information System (INIS)

    Dewji, S.; Bellamy, M.; Leggett, R.; Eckerman, K.; Hertel, N.; Sherbini, S.; Saba, M.

    2015-01-01

    Purpose: Estimated dose rates that may result from exposure to patients who had been administered iodine-131 ( 131 I) 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 131 I. Methods: Dose rates were estimated for members of the public potentially exposed to external irradiation from patients recently treated with 131 I. Tissue attenuation and iodine biokinetics were considered in the patient in a larger 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 131 I 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 131 I in the patient assumed a single voiding of urinary bladder contents that occurred during the trip at 2, 4, or 8 h after 131 I 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 131 I

  19. How to estimate exposure when studying the temperature-mortality relationship? A case study of the Paris area.

    Science.gov (United States)

    Schaeffer, Laura; de Crouy-Chanel, Perrine; Wagner, Vérène; Desplat, Julien; Pascal, Mathilde

    2016-01-01

    Time series studies assessing the effect of temperature on mortality generally use temperatures measured by a single weather station. In the Paris region, there is a substantial measurement network, and a variety of exposure indicators created from multiple stations can be tested. The aim of this study is to test the influence of exposure indicators on the temperature-mortality relationship in the Paris region. The relationship between temperature and non-accidental mortality was assessed based on a time series analysis using Poisson regression and a generalised additive model. Twenty-five stations in Paris and its three neighbouring departments were used to create four exposure indicators. These indicators were (1) the temperature recorded by one reference station, (2) a simple average of the temperatures of all stations, (3) an average weighted on the departmental population and (4) a classification of the stations based on land use and an average weighted on the population in each class. The relative risks and the Akaike criteria were similar for all the exposure indicators. The estimated temperature-mortality relationship therefore did not appear to be significantly affected by the indicator used, regardless of study zone (departments or region) or age group. The increase in temperatures from the 90(th) to the 99(th) percentile of the temperature distribution led to a significant increase in mortality over 75 years (RR = 1.10 [95% CI, 1.07; 1.14]). Conversely, the decrease in temperature between the 10(th) and 1(st) percentile had a significant effect on the mortality under 75 years (RR = 1.04 [95% CI, 1.01; 1.06]). In the Paris area, there is no added value in taking multiple climatic stations into account when estimating exposure in time series studies. Methods to better represent the subtle temperature variations in densely populated areas in epidemiological studies are needed.

  20. REVIEW OF DRAFT REVISED BLUE BOOK ON ESTIMATING CANCER RISKS FROM EXPOSURE TO IONIZING RADIATION

    Science.gov (United States)

    In 1994, EPA published a report, referred to as the “Blue Book,” which lays out EPA’s current methodology for quantitatively estimating radiogenic cancer risks. A follow-on report made minor adjustments to the previous estimates and presented a partial analysis of the uncertainti...

  1. Characteristics of left ventricular hypertrophy estimated by MIBG and BMIPP cardiac scintigraphy in patients undergoing peritoneal dialysis

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Hiroshige; Oda, Hiroshi; Ohno, Michiya; Watanabe, Sachirow; Kotoo, Yasunori; Matsuno, Yukihiko [Gifu Prefectural Hospital (Japan)

    2002-12-01

    Left ventricular hypertrophy (LVH) has been reported as a major factor in morbidity and mortality in chronic dialysis patients. However, cardiovascular mortality in peritoneal dialysis (PD) patients with LVH is substantially similar to that in hemodialysis (HD) patients. The present study sought to study whether sympathetic nerve activity and fatty acid metabolism of the myocardium estimated by {sup 123}I metaiodobenzylguanidine (MIBG) and {sup 123}I {beta}-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) myocardial scintigraphy are impaired or not in PD patients with LVH. The underlying disease of 45 PD patients enrolled in this study was chronic glomerulonephritis in all cases. Serum levels of natriuretic peptides (arterial natriuretic peptide (ANP), brain natriuretic peptide (BNP)) and free carnitine and MIBG, BMIPP myocardial scintigraphy and 2-dimensional echocardiography were measured in these 45 PD patients. The following results were obtained. The prevalence of increased left ventricular mass index (LVMI) was 84.4%. LVMI correlated with age, and serum levels of ANP and BNP, and inversely correlated with a heart-to-mediastinum ratio (H/M) estimated by MIBG and BMIPP myocardial scintigraphy. Percentages of the normal image of MIBG and BMIPP measured with a single photon emission computed tomography (SPECT) were 37.8% and 62.2%, respectively. The PD patients showing the diffuse defect of MIBG or BMIPP imaging had the decrease in left ventricular ejection fraction (LVEF). Especially, the serum level of free carnitine was reduced in the PD patients with diffuse defect of BMIPP SPECT. From these results, we concluded that PD patients with LVH showed impaired sympathetic nerve activity and fatty acid metabolism of the myocardium. Metabolic and functional disturbances of the myocardium may influence mortality in PD patients. (author)

  2. Possible use of food consumption surveys to estimate exposure to additives

    NARCIS (Netherlands)

    Löwik, M.R.H.

    1996-01-01

    Several methods can be and are being used to assess individual food consumption. Four types, namely 24-h recall, dietary records, food frequency and dietary history are discussed. For assessing the exposure to additives it is concluded that the dietary history method is probably the best choice

  3. Matrix Population Model for Estimating Effects from Time-Varying Aquatic Exposures: Technical Documentation

    Science.gov (United States)

    The Office of Pesticide Programs models daily aquatic pesticide exposure values for 30 years in its risk assessments. However, only a fraction of that information is typically used in these assessments. The population model employed herein is a deterministic, density-dependent pe...

  4. estimation of the sanitary impact associated to the domestic exposure to radon in Franche-Comte

    International Nuclear Information System (INIS)

    Catelinois, O.; Pirard, P.; Clinard, F.; Aury, K.; Tillier, C.; Aury, K.; Noury, L.; Hochard, A.

    2008-01-01

    The importance of the impact of public health associate to domestic radon exposure in Franche-Comte is clearly formulated. The radon concentrations are higher in the granite areas. However, the impact is essentially concentrated in the Franche-Comte sedimentary areas where the essential of the population lives. (N.C.)

  5. Development and Evaluation of an ADME-informed High Throughput Exposure Estimation Tool

    Science.gov (United States)

    EPA’s Chemical Safety for Sustainability (CSS) research program has been developing new ways to prioritize chemicals used in consumer products and articles. Using a risk-based methodology to account for both toxicity and exposure offers a comprehensive and systematic approa...

  6. Human health exposure factor estimates based upon a creel/angler survey of the lower Passaic River (part 3).

    Science.gov (United States)

    Ray, Rose; Craven, Valerie; Bingham, Matthew; Kinnell, Jason; Hastings, Elizabeth; Finley, Brent

    2007-03-15

    The results of an analysis of site-specific creel and angler information collected for the lower 6 miles of the Passaic River in Newark, NJ (Study Area), demonstrate that performing a site-specific creel/angler survey was essential to capture the unique characteristics of the anglers using the Study Area. The results presented were developed using a unique methodology for calculating site-specific, human exposure estimates from data collected in this unique urban/industrial setting. The site-specific human exposure factors calculated and presented include (1) size of angler population and fish-consuming population, (2) annual fish consumption rate, (3) duration of anglers' fishing careers, (4) cooking methods for the fish consumed, and (5) demographic information. Sensitivity and validation analyses were performed, and results were found to be useful for performing a site-specific, human health risk assessment. It was also concluded that site-specific exposure factor values are preferable to less representative "default values." The results of the analysis showed that the size of the angling population at the Study Area is estimated to range from 154 to 385 anglers, based on different methods of matching intercepts with anglers. Thirty-four anglers were estimated to have consumed fish; 37 people consumed fish from the river. The fish consumption rate for anglers using this area was best represented as 0.42 g/day for the central tendency and 1.8 g/day for the 95th percentile estimates. Anglers fishing at the river have relatively short fishing careers with a median of 0.9 yr, an average of 1.5 yr, and a 95th percentile of 4.8 yr. Consuming anglers tend to fry the fish they caught. The demographics of anglers who consume fish do not appear to differ substantially from those who do not, with no indication of a subsistence angling population.

  7. Estimation of internal exposure for exposed personnel from a CANDU nuclear fuel factory

    International Nuclear Information System (INIS)

    Horhoianu, Valeria; Valeca Monica; Hirica, Ovidiu; Todoran, Anca

    2004-01-01

    The knowledge of the radioactive material behaviour inside the human body is an essential issue for interpretation of the radioactivity measurements in human body or excretions in terms of internal contamination or committed equivalent dose. The paper presents evaluation of internal contamination of professionally exposed workers from a CANDU nuclear fuel factory with the ACRO computer code which estimates burden and tissue or organ dose resulting from inhalation or ingestion of radioactive materials. The workplaces where continuous aerosol sampling are carried out have been taken into account for the analysis. For potentially inhaled activity assessment, the average aerosol concentrations were estimated. The dose equivalent and collective dose equivalent are also estimated. (authors)

  8. Estimation of internal exposure for exposed personnel from a Candu nuclear fuel factory

    International Nuclear Information System (INIS)

    Horhoianu, V.; Hirica, O.; Valeca, M.; Todoran, A.

    2003-01-01

    The knowledge of the radioactive material behavior inside the human body is an essential issue for interpretation of the radioactivity measurements in human body or excretions in terms of internal contamination or committed equivalent dose. The paper present evaluation of internal contamination of professionally exposed workers from a Candu nuclear fuel factory with the ACRO computer code which estimate burden and tissue or organ dose resulting from inhalation or ingestion of radioactive materials. The workplaces where continuos aerosols sampling are carried out, has been taken into account for the analysis. For potentially inhaled activity assessment, the average aerosol concentrations were estimated. The dose equivalent and collective dose equivalent are also estimated. (authors)

  9. The optimal UV exposure time for vitamin D3 synthesis and erythema estimated by UV observations in Korea

    Science.gov (United States)

    Lee, Y. G.; Koo, J. H.

    2016-12-01

    Solar UV radiation in a wavelength range between 280 to 400 nm has both positive and negative influences on human body. Surface UV radiation is the main natural source of vitamin D, providing the promotion of bone and musculoskeletal health and reducing the risk of a number of cancers and other medical conditions. However, overexposure to surface UV radiation is significantly related with the majority of skin cancer, in addition other negative health effects such as sunburn, skin aging, and some forms of eye cataracts. Therefore, it is important to estimate the optimal UV exposure time, representing a balance between reducing negative health effects and maximizing sufficient vitamin D production. Previous studies calculated erythemal UV and vitamin-D UV from the measured and modelled spectral irradiances, respectively, by weighting CIE Erythema and Vitamin D3 generation functions (Kazantzidis et al., 2009; Fioletov et al., 2010). In particular, McKenzie et al. (2009) suggested the algorithm to estimate vitamin-D production UV from erythemal UV (or UV index) and determined the optimum conditions of UV exposure based on skin type Ⅱ according to the Fitzpatrick (1988). Recently, there are various demands for risks and benefits of surface UV radiation on public health over Korea, thus it is necessary to estimate optimal UV exposure time suitable to skin type of East Asians. This study examined the relationship between erythemally weighted UV (UVEry) and vitamin D weighted UV (UVVitD) from spectral UV measurements during 2006-2010. The temporal variations of the ratio (UVVitD/UVEry) were also analyzed and the ratio as a function of UV index was applied to the broadband UV measured by UV-Biometer at 6 sites in Korea Thus, the optimal UV exposure time for vitamin D3 synthesis and erythema was estimated for diurnal, seasonal, and annual scales over Korea. In summer with high surface UV radiation, short exposure time leaded to sufficient vitamin D and erythema and vice

  10. Estimating patient dose from CT exams that use automatic exposure control: Development and validation of methods to accurately estimate tube current values.

    Science.gov (United States)

    McMillan, Kyle; Bostani, Maryam; Cagnon, Christopher H; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia H; McNitt-Gray, Michael F

    2017-08-01

    The vast majority of body CT exams are performed with automatic exposure control (AEC), which adapts the mean tube current to the patient size and modulates the tube current either angularly, longitudinally or both. However, most radiation dose estimation tools are based on fixed tube current scans. Accurate estimates of patient dose from AEC scans require knowledge of the tube current values, which is usually unavailable. The purpose of this work was to develop and validate methods to accurately estimate the tube current values prescribed by one manufacturer's AEC system to enable accurate estimates of patient dose. Methods were developed that took into account available patient attenuation information, user selected image quality reference parameters and x-ray system limits to estimate tube current values for patient scans. Methods consistent with AAPM Report 220 were developed that used patient attenuation data that were: (a) supplied by the manufacturer in the CT localizer radiograph and (b) based on a simulated CT localizer radiograph derived from image data. For comparison, actual tube current values were extracted from the projection data of each patient. Validation of each approach was based on data collected from 40 pediatric and adult patients who received clinically indicated chest (n = 20) and abdomen/pelvis (n = 20) scans on a 64 slice multidetector row CT (Sensation 64, Siemens Healthcare, Forchheim, Germany). For each patient dataset, the following were collected with Institutional Review Board (IRB) approval: (a) projection data containing actual tube current values at each projection view, (b) CT localizer radiograph (topogram) and (c) reconstructed image data. Tube current values were estimated based on the actual topogram (actual-topo) as well as the simulated topogram based on image data (sim-topo). Each of these was compared to the actual tube current values from the patient scan. In addition, to assess the accuracy of each method in estimating

  11. The estimation of effective doses using measurement of several relevant physical parameters from radon exposures

    International Nuclear Information System (INIS)

    Ridzikova, A; Fronka, A.; Maly, B.; Moucka, L.

    2003-01-01

    In the present investigation, we will be study the dose relevant factors from continual monitoring in real homes into account getting more accurate estimation of 222 Rn the effective dose. The dose relevant parameters include the radon concentration, the equilibrium factor (f), the fraction (fp) of unattached radon decay products and real time occupancy people in home. The result of the measurement are the time courses of radon concentration that are based on estimation effective doses together with assessment of the real time occupancy people indoor. We found out by analysis that year effective dose is lower than effective dose estimated by ICRP recommendation from the integral measurement that included only average radon concentration. Our analysis of estimation effective doses using measurement of several physical parameters was made only in one case and for the better specification is important to measure in different real occupancy houses. (authors)

  12. Estimated effective dose rates from radon exposure in workplaces and residences within Los Alamos county in New Mexico

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

    Many millions of office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the workplace are lacking. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were then used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about nine times greater exposure at home than while in the office (691 mrem yr{sup -1} versus 78 mrem yr{sup -1}). The estimated effective dose rate for a more homebound person was 896 mrem yr{sup -1}. These effective dose rates are contrasted against the 100 mrem yr{sup -1} threshold for regulation of a 'radiological worker' defined in the Department of Energy regulations occupational exposure and the 10 mrem yr{sup -1} air pathway effective public dose limit regulated by the Environmental Protection Agency.

  13. National Estimates of Exposure to Traumatic Events and PTSD Prevalence Using DSM-IV and DSM-5 Criteria

    Science.gov (United States)

    Kilpatrick, Dean G.; Resnick, Heidi S.; Milanak, Melissa E.; Miller, Mark W.; Keyes, Katherine M.; Friedman, Matthew J.

    2014-01-01

    Prevalence of posttraumatic stress disorder (PTSD) defined according to the American Psychiatric Association’s Diagnostic and Statistical Manual fifth edition (DSM-5; 2013) and fourth edition (DSM-IV; 1994) was compared in a national sample of U.S. adults (N = 2,953) recruited from an online panel. Exposure to traumatic events, PTSD symptoms, and functional impairment were assessed online using a highly structured, self-administered survey. Traumatic event exposure using DSM-5 criteria was high (89.7%), and exposure to multiple traumatic event types was the norm. PTSD caseness was determined using Same Event (i.e., all symptom criteria met to the same event type) and Composite Event (i.e., symptom criteria met to a combination of event types) definitions. Lifetime, past-12-month, and past 6-month PTSD prevalence using the Same Event definition for DSM-5 was 8.3%, 4.7%, and 3.8% respectively. All 6 DSM-5 prevalence estimates were slightly lower than their DSM-IV counterparts, although only 2 of these differences were statistically significant. DSM-5 PTSD prevalence was higher among women than among men, and prevalence increased with greater traumatic event exposure. Major reasons individuals met DSM-IV criteria, but not DSM-5 criteria were the exclusion of nonaccidental, nonviolent deaths from Criterion A, and the new requirement of at least 1 active avoidance symptom. PMID:24151000

  14. Estimation of exposure to sunlight of the liner under a tiled roof

    DEFF Research Database (Denmark)

    Holck, Ole; Rosenfeld, J.L.J.

    2005-01-01

    One construction for a pitched roof is to use tiles on battens, with a liner attached below the battens. The shape of some types of tiles is such that, at each corner where four tiles overlap, a small gap is formed. At certain positions of the sun solar radiation can penetrate through these gaps....... Simulations were carried out for a roof tilted at 25degrees, 35degrees or 45degrees, facing SE, S, SW or W. For the particular roof construction and gap studied, the maximum annual exposure of a 25 mm(2) piece of the liner placed 150 mm below the gap (corresponding to about 100 mm below the base of the tiles...... to the roof. Analytic expressions for the size of the illuminated area are obtained using a thick slit model. The accuracy of the model was assessed by some experimental measurements. The exposure over one year of the roof liner was calculated using the Design Reference Year for Copenhagen, Denmark...

  15. National estimates and correlates of secondhand smoke exposure in US cancer survivors.

    Science.gov (United States)

    Asfar, Taghrid; Arheart, Kristopher L; Koru-Sengul, Tulay; Byrne, Margaret M; Dietz, Noella A; Chen, Charles Jeng; Lee, David J

    2017-08-01

    Cancer survivors comprise a vulnerable population for exposure to secondhand smoke (SHS). This study examined and compared the prevalence, time trends, and predictors of SHS exposure between nonsmoking adult cancer survivors and nonsmoking adults without cancer history (control group). Data were obtained from the 2001-2012 National Health and Nutrition Examination Survey (survivors: n = 2168; controls: n = 19,436). All adults ≥20 years of age who reported not smoking and had a serum cotinine level of 0.015-10 ng/mL were included in the study. Prevalence and 95% confidence intervals, weighted linear regression of prevalence on year for trend analysis, and logistic regression analysis were performed with adjustments made for the complex survey design. Survivors were significantly less likely to be exposed to SHS (65.4 vs. 70.6%, respectively). Exposure over time decreased by 16% (from 67.1% in 2001 to 53.3% in 2012) among survivors and by 24% (from 72% in 2001 to 56% in 2012) among controls. Exposed survivors were more likely to be young (OR = 0.98 [95% CI = 0.97-0.99]), non-Hispanic Black (2.51 [1.49-4.26]), with some college education (2.47 [1.56-3.93]), a high school education (2.72 [1.76-4.19]), less than a high school education (2.49 [1.58-3.91]), and poor (1.80 [1.10-2.96]). Considerable numbers of US cancer survivors are exposed to SHS and exposure disparities persist. More efforts are needed to develop and test population policies and clinical-based interventions targeting cancer survivors.

  16. Estimating children's exposure to toxic elements in contaminated toys and children's jewelry via saliva mobilization.

    Science.gov (United States)

    Guney, Mert; Nguyen, Alain; Zagury, Gerald J

    2014-09-19

    Children's potential for exposure to potentially toxic elements in contaminated jewelry and toys via mouth contact has not yet been fully evaluated. Various toys and jewelry (metallic toys and jewelry [MJ], plastic toys, toys with paint or coating, and brittle/pliable toys; n = 32) were tested using the saliva extraction (mouthing) compartment of the DIN and RIVM bioaccessibility protocols to assess As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sb, and Se mobilization via saliva. Total concentrations of As, Cd, Cu, Ni, Pb, and Sb were found elevated in analyzed samples. Four metals were mobilized to saliva from 16 MJ in significant quantities (>1 μg for highly toxic Cd and Pb, >10 μg for Cu and Ni). Bioaccessible concentrations and hazard index values for Cd exceeded limit values, for young children between 6 mo- and 3 yr-old and according to both protocols. Total and bioaccessible metal concentrations were different and not always correlated, encouraging the use of bioaccessibility for more accurate hazard assessments. Bioaccessibility increased with increasing extraction time. Overall, the risk from exposure to toxic elements via mouthing was high only for Cd and for MJ. Further research on children's exposure to toxic elements following ingestion of toy or jewelry material is recommended.

  17. Improving substance information in usetox®, part 2: Data for estimating fate and ecosystem exposure factors

    DEFF Research Database (Denmark)

    Saouter, Erwan; Aschberger, Karin; Fantke, Peter

    2017-01-01

    substance properties, USEtox® quantifies potential human toxicity and freshwater ecotoxicity impacts by combining environmental fate, exposure and toxicity effects information, considering multimedia fate and multi-pathway exposure processes. The main source to obtain substance properties for USEtox® 1......The scientific consensus model USEtox® is developed since 2003 under the auspices of the UNEP-SETAC Life Cycle Initiative as a harmonized approach for characterizing human and freshwater toxicity in life cycle assessment (LCA) and other comparative assessment frameworks. Using physicochemical.......01 and 2.0 is the Estimation Program Interface (EPI SuiteTM ) from the U.S. Environmental Protection Agency. However, since the development of the original USEtox® substance databases, new chemical regulations have been enforced in Europe such as the REACH and the Plant Protection Products regulations...

  18. Randomization of grab-sampling strategies for estimating the annual exposure of U miners to Rn daughters.

    Science.gov (United States)

    Borak, T B

    1986-04-01

    Periodic grab sampling in combination with time-of-occupancy surveys has been the accepted procedure for estimating the annual exposure of underground U miners to Rn daughters. Temporal variations in the concentration of potential alpha energy in the mine generate uncertainties in this process. A system to randomize the selection of locations for measurement is described which can reduce uncertainties and eliminate systematic biases in the data. In general, a sample frequency of 50 measurements per year is sufficient to satisfy the criteria that the annual exposure be determined in working level months to within +/- 50% of the true value with a 95% level of confidence. Suggestions for implementing this randomization scheme are presented.

  19. Risk estimates for meningiomas and other late effects after diagnostic X-ray exposure of the skull

    International Nuclear Information System (INIS)

    Pflugbeil, S.; Pflugbeil, C.; Schmitz-Feuerhake, I.

    2011-01-01

    This study aims to investigate the contribution of diagnostic exposures to the rising rates of brain tumours and other neoplasms which are observed in several industrial nations. Included are benign tumours in the head and neck region and cataracts which are neglected in usual risk estimates by international and national radiation protection committees. Dose-effect relationships for tumours of the brain, skin, thyroid and other sites of the head region, leukaemia and cataracts are taken from the literature. Risk estimates are derived for paediatric head computed tomographies (CTs) as well as for brain tumours in adults. On the basis of estimates for Germany about the number of head scans, the annual rate of radiation-induced diseases is calculated. About 1000 annual paediatric CT investigations of the skull will lead to about three excess neoplasms in the head region, i.e. the probability of an induced late effect must be suspected in the range of some thousands. Additionally, a relevant increase of cataracts must be considered. The radiation-induced occurrence of meningiomas and other brain tumours most probably contributes to the continuously increasing incidence of these diseases which is observed in several industrial nations, as well as the exposure of the bone marrow by CT to the increase of childhood leukaemia. (authors)

  20. Estimation of the Altai region population exposure resulting from the nuclear tests at the Semipalatinsk test site

    International Nuclear Information System (INIS)

    Djachenko, V.I.; Gabbasov, M.N.; Laborev, V.M.; Markovtsev, A.S.; Sudakov, V.V.; Volobuyev, N.M.; Zelenov, V.I.; Lagutin, A.A.; Shoikher, J.N.

    1998-01-01

    The historical roots of reconstruction of doses received by populations from nuclear tests date back to the 60''s, when the world faced a problem of growing radioactive contamination by radioactive fallout resulting from atmospheric nuclear tests. Since then, only one aspect of this problem has been properly developed, namely: public-exposure doses resulting from the global radioactive fallout have been estimated. Local fallout, which occurred mainly in the territories of the test sites and regions adjacent to their boundaries, was considered and studied as an internal affair of the states. The first steps in creating the above-mentioned methodological basis were taken in Russia, where, by now, the methodology of dose estimation in regions of local radioactive fallout has been determined and acknowledged nationwide as a standard document (Federal Committee on Sanitay Epidemiological Control of RF, 1994). It was this methodology that was used for calculations and dose estimation of the exposure of the Altai population from the Semipalatinsk Test Site (STS). (orig./GL)

  1. High-throughput migration modelling for estimating exposure to chemicals in food packaging in screening and prioritization tools.

    Science.gov (United States)

    Ernstoff, Alexi S; Fantke, Peter; Huang, Lei; Jolliet, Olivier

    2017-11-01

    Specialty software and simplified models are often used to estimate migration of potentially toxic chemicals from packaging into food. Current models, however, are not suitable for emerging applications in decision-support tools, e.g. in Life Cycle Assessment and risk-based screening and prioritization, which require rapid computation of accurate estimates for diverse scenarios. To fulfil this need, we develop an accurate and rapid (high-throughput) model that estimates the fraction of organic chemicals migrating from polymeric packaging materials into foods. Several hundred step-wise simulations optimised the model coefficients to cover a range of user-defined scenarios (e.g. temperature). The developed model, operationalised in a spreadsheet for future dissemination, nearly instantaneously estimates chemical migration, and has improved performance over commonly used model simplifications. When using measured diffusion coefficients the model accurately predicted (R 2  = 0.9, standard error (S e ) = 0.5) hundreds of empirical data points for various scenarios. Diffusion coefficient modelling, which determines the speed of chemical transfer from package to food, was a major contributor to uncertainty and dramatically decreased model performance (R 2  = 0.4, S e  = 1). In all, this study provides a rapid migration modelling approach to estimate exposure to chemicals in food packaging for emerging screening and prioritization approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Preliminary estimation of infantile exposure to BPA based on the standard quality of baby bottles distributed in Isfahan urban society

    Directory of Open Access Journals (Sweden)

    Zohreh Abdi Moghadam

    2013-01-01

    Full Text Available Aims: This study was aimed to estimate the bisphenol A (BPA intake from baby bottles, considering the diversity and the standard quality of the baby bottles distributed in an Isfahan urban society. Materials and Methods: A cross-sectional study was performed in Isfahan in 2011. Baby shops ( n = 33 and drug stores ( n = 7 in four district areas were included in the study. The distribution of baby bottles was investigated regarding their brand, origin, and being labeled "BPA free." Estimation of exposure to BPA from baby bottles was made based on the national and international representative data. Results: The products marked as "BPA free" were found among the western products and limited to two of the selected areas. No "BPA free" marked baby bottle was distinguished among the Iranian made products. Of the 8% exclusively formula-fed infants, 90% may be the high consumers of BPA from polycarbonate baby bottles, with an intake of 1.5-2 μg/kg b.w./day for the moderate and 7.5-10 μg/kg b.w./day in case of worse condition. Conclusion: Considering the current globally accepted threshold daily intake (TDI for BPA, primary exposure estimation is that feeding using non-BPA-free baby bottles is not a serious health concern in Iran. Thought that threshold level of TDI is discussed to be reduced in future, improvement and revision of the national standards can be effective in reducing the exposure to BPA in Iranian infants so as to provide large margin of safety for them.

  3. Assessment of impact of urbanisation on background radiation exposure and human health risk estimation in Kuala Lumpur, Malaysia.

    Science.gov (United States)

    Sanusi, M S M; Ramli, A T; Hassan, W M S W; Lee, M H; Izham, A; Said, M N; Wagiran, H; Heryanshah, A

    2017-07-01

    Kuala Lumpur has been undergoing rapid urbanisation process, mainly in infrastructure development. The opening of new township and residential in former tin mining areas, particularly in the heavy mineral- or tin-bearing alluvial soil in Kuala Lumpur, is a contentious subject in land-use regulation. Construction practices, i.e. reclamation and dredging in these areas are potential to enhance the radioactivity levels of soil and subsequently, increase the existing background gamma radiation levels. This situation is worsened with the utilisation of tin tailings as construction materials apart from unavoidable soil pollutions due to naturally occurring radioactive materials in construction materials, e.g. granitic aggregate, cement and red clay brick. This study was conducted to assess the urbanisation impacts on background gamma radiation in Kuala Lumpur. The study found that the mean value of measured dose rate was 251±6nGyh -1 (156-392nGyh -1 ) and 4 times higher than the world average value. High radioactivity levels of 238 U (95±12Bqkg -1 ), 232 Th (191±23Bqkg -1 ,) and 40 K (727±130Bqkg -1 ) in soil were identified as the major source of high radiation exposure. Based on statistical ANOVA, t-test, and analyses of cumulative probability distribution, this study has statistically verified the dose enhancements in the background radiation. The effective dose was estimated to be 0.31±0.01mSvy -1 per man. The recommended ICRP reference level (1-20mSvy -1 ) is applicable to the involved existing exposure situation in this study. The estimated effective dose in this study is lower than the ICRP reference level and too low to cause deterministic radiation effects. Nevertheless based on estimations of lifetime radiation exposure risks, this study found that there was small probability for individual in Kuala Lumpur being diagnosed with cancer and dying of cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Estimation of doses to patients with chronic radiation sickness from external occupational exposure

    International Nuclear Information System (INIS)

    Jia Delin; Dai Guangfu

    1991-01-01

    The doses to patients with chronic radiation sickness who had engaged in diagnostic radiology have been estimated according to the radiation work load, type and capacity of X-ray equipment, protection conditions, data of nationwide survey on doses to X-ray workers in China, or the data of dose monitoring in working places. Based on the activities of radium sources, time taken up in performing radium therapy, distance to radium sources and radiation work load, the doses to patients who had engaged in radium therapy have been estimated. The results of estimated average doses for 29 cases of chronic radiation sickness are given. Their average red marrow dose, trunk dose and effective dose equivalent are 1.3 Gy, 1.2 Gy and 1.6 Sv, respectively

  5. Estimation of Internal Exposure for Exposed Personnel from a CANDU Nuclear Fuel Factory

    International Nuclear Information System (INIS)

    Horhoianu, V.; Valeca, M.; Margeanu, S.

    2001-01-01

    Full text: The knowledge of the radioactive material behaviour inside the human body is an essential issue for interpretation of the radioactivity measurements in human body or excretions in terms of internal contamination or committed equivalent dose. The paper presents evaluation of internal contamination of professionally exposed workers from a CANDU nuclear fuel factory with the ACRO computer code which estimate burden and tissue or organ dose resulting from inhalation or ingestion of radioactive materials. The workplaces where continuos aerosols sampling are carried out, has been taken into account for the analysis. For potentially inhaled activity assessment, the average aerosol concentrations were estimated. The dose equivalent and collective dose equivalent are also estimated. (author)

  6. Estimation of monthly solar exposure on horizontal surface by Angstrom-type regression equation

    International Nuclear Information System (INIS)

    Ravanshid, S.H.

    1981-01-01

    To obtain solar flux intensity, solar radiation measuring instruments are the best. In the absence of instrumental data there are other meteorological measurements which are related to solar energy and also it is possible to use empirical relationships to estimate solar flux intensit. One of these empirical relationships to estimate monthly averages of total solar radiation on a horizontal surface is the modified angstrom-type regression equation which has been employed in this report in order to estimate the solar flux intensity on a horizontal surface for Tehran. By comparing the results of this equation with four years measured valued by Tehran's meteorological weather station the values of meteorological constants (a,b) in the equation were obtained for Tehran. (author)

  7. Theoretical vs. measured risk estimates for the external exposure to ionizing radiation pathway - a case study of a major industrial site

    International Nuclear Information System (INIS)

    Dundon, S.T.

    1996-01-01

    Two methods of estimating the risk to industrial receptors to ionizing radiation are presented here. The first method relies on the use of the U.S. Environmental Protection Agency (EPA) external exposure slope factor combined with default exposure parameters for industrial land uses. The second method employs measured exposure rate date and site-specific exposure durations combined with the BEIR V radiological risk coefficient to estimate occupational risk. The uncertainties in each method are described qualitatively. Site-specific information was available for the exposure duration and the exposure frequency as well as historic dosimetry information. Risk estimates were also generated for the current regulatory cleanup level (removal risks included) and for a no action scenario. The study showed that uncertainties for risks calculated using measured exposure rates and site-specific exposure parameters were much lower and defendable than using EPA slope factors combined with default exposure parameters. The findings call into question the use of a uniform cleanup standard for depleted uranium that does not account for site-specific land uses and relies on theoretical models rather than measured exposure rate information

  8. An international comparison of models and approaches for the estimation of the radiological exposure of non-human biota

    International Nuclear Information System (INIS)

    Beresford, Nicholas A.; Balonov, Mikhail; Beaugelin-Seiller, Karine; Brown, Justin; Copplestone, David; Hingston, Joanne L.; Horyna, Jan; Hosseini, Ali; Howard, Brenda J.; Kamboj, Sunita; Nedveckaite, Tatjana; Olyslaegers, Geert; Sazykina, Tatiana; Vives i Batlle, Jordi; Yankovich, Tamara L.; Yu, Charley

    2008-01-01

    Over the last decade a number of models and approaches have been developed for the estimation of the exposure of non-human biota to ionising radiations. In some countries these are now being used in regulatory assessments. However, to date there has been no attempt to compare the outputs of the different models used. This paper presents the work of the International Atomic Energy Agency's EMRAS Biota Working Group which compares the predictions of a number of such models in model-model and model-data inter-comparisons

  9. Low cadmium exposure in males and lactating females–estimation of biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Stajnko, Anja [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, Jamova 39, Ljubljana (Slovenia); Falnoga, Ingrid, E-mail: ingrid.falnoga@ijs.si [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana (Slovenia); Tratnik, Janja Snoj; Mazej, Darja [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana (Slovenia); Jagodic, Marta [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, Jamova 39, Ljubljana (Slovenia); Krsnik, Mladen [Institute of Clinical Chemistry and Biochemistry, University Medical Centre Ljubljana, Njegoševa 4, Ljubljana (Slovenia); Kobal, Alfred B. [Department of Occupational Health, Idrija Mercury Mine, Arkova 43, Idrija (Slovenia); Prezelj, Marija [Institute of Clinical Chemistry and Biochemistry, University Medical Centre Ljubljana, Njegoševa 4, Ljubljana (Slovenia); Kononenko, Lijana [Chemical Office of RS, Ministry of Health of RS, Ajdovščina 4, Ljubljana (Slovenia); Horvat, Milena [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, Jamova 39, Ljubljana (Slovenia)

    2017-01-15

    Background: Urine cadmium (Cd) and renal function biomarkers, mostly analysed in urine spot samples, are well established biomarkers of occupational exposure. Their use and associations at low environmental level are common, but have recently been questioned, particularly in terms of physiological variability and normalisation bias in the case of urine spot samples. Aim: To determine the appropriateness of spot urine and/or blood Cd exposure biomarkers and their relationships with renal function biomarkers at low levels of exposure. To this end, we used data from Slovenian human biomonitoring program involving 1081 Slovenians (548 males, mean age 31 years; 533 lactating females, mean age 29 years; 2007–2015) who have not been exposed to Cd occupationally. Results: Geometric means (GMs) of Cd in blood and spot urine samples were 0.27 ng/mL (0.28 for males and 0.33 for females) and 0.19 ng/mL (0.21 for males and 0.17 for females), respectively. Differing results were obtained when contrasting normalisation by urine creatinine with specific gravity. GMs of urine albumin (Alb), alpha-1-microglobulin (A1M), N-acetyl-beta-glucosaminidase (NAG), and immunoglobulin G (IgG) were far below their upper reference limits. Statistical analysis of unnormalised or normalised urine data often yielded inconsistent and conflicting results (or trends), so association analyses with unnormalised data were taken as more valid. Relatively weak positive associations were observed between urine Cd (ng/mL) and blood Cd (β=0.11, p=0.002 for males and β=0.33, p<0.001 for females) and for females between urine NAG and blood Cd (β=0.14, p=0.04). No associations were found between other renal function biomarkers and blood Cd. Associations between Cd and renal function biomarkers in urine were stronger (p<0.05, β=0.11–0.63). Mostly, all of the associations stayed significant but weakened after normalisation for diuresis. In the case of A1M, its associations with Cd were influenced by

  10. Low cadmium exposure in males and lactating females–estimation of biomarkers

    International Nuclear Information System (INIS)

    Stajnko, Anja; Falnoga, Ingrid; Tratnik, Janja Snoj; Mazej, Darja; Jagodic, Marta; Krsnik, Mladen; Kobal, Alfred B.; Prezelj, Marija; Kononenko, Lijana; Horvat, Milena

    2017-01-01

    Background: Urine cadmium (Cd) and renal function biomarkers, mostly analysed in urine spot samples, are well established biomarkers of occupational exposure. Their use and associations at low environmental level are common, but have recently been questioned, particularly in terms of physiological variability and normalisation bias in the case of urine spot samples. Aim: To determine the appropriateness of spot urine and/or blood Cd exposure biomarkers and their relationships with renal function biomarkers at low levels of exposure. To this end, we used data from Slovenian human biomonitoring program involving 1081 Slovenians (548 males, mean age 31 years; 533 lactating females, mean age 29 years; 2007–2015) who have not been exposed to Cd occupationally. Results: Geometric means (GMs) of Cd in blood and spot urine samples were 0.27 ng/mL (0.28 for males and 0.33 for females) and 0.19 ng/mL (0.21 for males and 0.17 for females), respectively. Differing results were obtained when contrasting normalisation by urine creatinine with specific gravity. GMs of urine albumin (Alb), alpha-1-microglobulin (A1M), N-acetyl-beta-glucosaminidase (NAG), and immunoglobulin G (IgG) were far below their upper reference limits. Statistical analysis of unnormalised or normalised urine data often yielded inconsistent and conflicting results (or trends), so association analyses with unnormalised data were taken as more valid. Relatively weak positive associations were observed between urine Cd (ng/mL) and blood Cd (β=0.11, p=0.002 for males and β=0.33, p<0.001 for females) and for females between urine NAG and blood Cd (β=0.14, p=0.04). No associations were found between other renal function biomarkers and blood Cd. Associations between Cd and renal function biomarkers in urine were stronger (p<0.05, β=0.11–0.63). Mostly, all of the associations stayed significant but weakened after normalisation for diuresis. In the case of A1M, its associations with Cd were influenced by

  11. Estimating Burden and Disease Costs of Exposure to Endocrine-Disrupting Chemicals in the European Union

    DEFF Research Database (Denmark)

    Trasande, Leonardo; Zoeller, R. Thomas; Hass, Ulla

    2015-01-01

    Rapidly increasing evidence has documented that endocrine-disrupting chemicals (EDCs) contribute substantially to disease and disability. Objective: The objective was to quantify a range of health and economic costs that can be reasonably attributed to EDC exposures in the European Union (EU......). Design: A Steering Committee of scientists adapted the Intergovernmental Panel on Climate Change weight-of-evidence characterization for probability of causation based upon levels of available epidemiological and toxicological evidence for one or more chemicals contributing to disease by an endocrine...

  12. Estimation of radiation exposures due to the exemption of beta-contaminated radioactive materials

    International Nuclear Information System (INIS)

    Beltz, D.; Botsch, W.; Huettig, M.; Boerchers, F.

    2005-01-01

    The authors have checked the individual clearance levels of pure beta-emitters (Sr 89, Sr 90+) according to Anlage III, Table 1, column 8 and 10 StrlSchV for the clearance of buildings. According to Monte-Carlo simulations the direct exposure coming from contaminated parts of a building can exceed the range of trivial doses significantly, although the clearance levels are met. Furthermore, the high radiation level outside a barrel of beta-emitting waste showed that even the mass-specific clearance levels for the disposal of beta-contaminated waste need to be reviewed. (orig.)

  13. Simplified methods for estimating gamma exposure fields transmitted through straight rectangular ducts

    International Nuclear Information System (INIS)

    Shultis, J.K.; Thompson, K.R.; Faw, R.E.

    1986-01-01

    Approximate computational models are developed to describe the spatial variation in the radiation field transmitted through a straight reactangular duct obliquely illuminated by monoenergetic gamma photons. These models account for single and multiple scattering from the duct walls and lips as well as for direct penetration by the photons. Results of calculations are compared to results from a recent benchmark duct streaming experiment, and empirical correction factors are obtained which enable the models to predict the transmitted exposure rates to within 20% of the experimental values

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

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1981-01-01

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

  15. The measurement of constitutive and facultative skin pigmentation and estimation of sun exposure in Caucasians with basal cell carcinoma and cutaneous malignant melanoma

    DEFF Research Database (Denmark)

    Lock-Andersen, J; Drzewiecki, K T; Wulf, H C

    1998-01-01

    but indicated high exposure levels in childhood and youth and in adult leisure time. Sun exposure estimated by increase in facultative pigmentation above the constitutive level (the Sun Exposure Index) was not significantly different between BCC patients and controls, whereas CMM men patients had higher...... and 174 matched controls and in 168 CMM patients and 176 matched controls. Measurements were performed at the forehead, the upper chest, the upper back, the lateral and medial aspects of the upper arm, and the buttocks. Self-estimation of sun exposure in childhood, in youth and in adulthood was performed...... between BCC patients and controls except that women patients had higher pigmentation at the lateral side of the upper arm. For CMM, men patients had higher pigmentation at the lateral side of the upper arm. Self-estimations of sun exposure did not show differences between patients and controls...

  16. Children's Phthalate Intakes and Resultant Cumulative Exposures Estimated from Urine Compared with Estimates from Dust Ingestion, Inhalation and Dermal Absorption in Their Homes and Daycare Centers

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Weschler, Charles J; Langer, Sarka

    2013-01-01

    Total daily intakes of diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) were calculated from phthalate metabolite levels measured in the urine of 431 Danish children between 3 and 6 years of a...... of certain phthalates. Such exposures, by themselves, may lead to intakes exceeding current limit values.......Total daily intakes of diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) were calculated from phthalate metabolite levels measured in the urine of 431 Danish children between 3 and 6 years of age....... For each child the intake attributable to exposures in the indoor environment via dust ingestion, inhalation and dermal absorption were estimated from the phthalate levels in the dust collected from the child's home and daycare center. Based on the urine samples, DEHP had the highest total daily intake...

  17. Estimation of radiation exposure for hot cell workers during DUPIC fuel fabrication process in IMEF M6 cell

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Yong Bum; Baek, Sang Yeol; Park, Dae Kyu

    1997-06-01

    DUPIC(Direct Use of spent PWR fuel In CANDU) fuel cycle to utilize the PWR spent fuel in fabricating CANDU fuel, which is expected to reduce not only the total amount of high level radwastes but the energy sources is underway. IMEF M6 cell to be used as DUPIC fuel fabrication facility is refurbished and retrofitted. Radiation exposure for the hot cell worker by dispersion of the radioactive materials during the DUPIC process were estimated on the basis of the hot cell design information. According to the estimation results, DUPIC fuel fabrication process could be run without any severe impacts to the hot cell workers when the ventilation system to maintain the sufficient pressure difference between hotcell and working area and radiation monitoring system is supports the hot cell operation properly. (author). 4 tabs., 6 figs.

  18. Development of a head simulator for exposure dose estimation on patients exposed by odontological X-rays

    International Nuclear Information System (INIS)

    Moura Neto, Francisco N.; Batista, Eutropio V.; Santos, Adriano M.

    2009-01-01

    In the obtaining a odontological radiography, the individual is exposed to te radiation and part of that radiation will be absorbed by his organism. The estimative of absorbed dose can be accomplished through calculations where are considered: the distance from the source to the individual, the energy of the emitted X-ray at the moment of the exposure and the bode region exposed; and as that option does not possess great precision, alternative forms are seek for the quantification such doses. This work proposes the construction of a head simulator to be used in the estimative of absorbed dose in patients, during the accomplishment of the odontological radiographic examinations. As a perspective of work, it is intended to use the phantom to help in the absorbed doses for obtainment of parameters in X-ray odontological devices, contributing of image obtainment with more quality and less radiation dose in the patient

  19. Monitoring of perchlorate in diverse foods and its estimated dietary exposure for Korea populations.

    Science.gov (United States)

    Lee, Ji-Woo; Oh, Sung-Hee; Oh, Jeong-Eun

    2012-12-01

    The perchlorate concentrations in various Korean food samples were monitored, and 663 samples belonging to 39 kinds of food were analyzed. The analysis results revealed that dairy products contain the highest average concentration of 6.34 μg/kg and high detection frequency of over 85%. Fruit and vegetables showed the next highest perchlorate concentration with an average of 6.17 μg/kg. Especially, with its average concentration of 39.9 μg/kg, spinach showed the highest perchlorate level among all target food samples studied. Tomato was followed by spinach, which showed a high perchlorate average concentration of 19.8 μg/kg, and over 7 μg/kg was detected in ham and sausage (avg. 7.31 μg/kg) and in instant noodles (avg. 7.58 μg/kg). Less than 2 μg/kg was detected in fishes, meats and beverages. The exposure dose of perchlorate in Korean by food intake was calculated on the basis of the analyzed perchlorate levels in this study. The daily perchlorate dose to which Korean adults are exposed is 0.04 μg/kg bw/day, which is lower than the RfD (0.7 μg/kg bw/day) value suggested by US NAS. This result indicates that Korean people's current exposure to perchlorate from domestic food consumption is evaluated as safe. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Validating novel air pollution sensors to improve exposure estimates for epidemiological analyses and citizen science.

    Science.gov (United States)

    Jerrett, Michael; Donaire-Gonzalez, David; Popoola, Olalekan; Jones, Roderic; Cohen, Ronald C; Almanza, Estela; de Nazelle, Audrey; Mead, Iq; Carrasco-Turigas, Glòria; Cole-Hunter, Tom; Triguero-Mas, Margarita; Seto, Edmund; Nieuwenhuijsen, Mark

    2017-10-01

    Low cost, personal air pollution sensors may reduce exposure measurement errors in epidemiological investigations and contribute to citizen science initiatives. Here we assess the validity of a low cost personal air pollution sensor. Study participants were drawn from two ongoing epidemiological projects in Barcelona, Spain. Participants repeatedly wore the pollution sensor - which measured carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO 2 ). We also compared personal sensor measurements to those from more expensive instruments. Our personal sensors had moderate to high correlations with government monitors with averaging times of 1-h and 30-min epochs (r ~ 0.38-0.8) for NO and CO, but had low to moderate correlations with NO 2 (~0.04-0.67). Correlations between the personal sensors and more expensive research instruments were higher than with the government monitors. The sensors were able to detect high and low air pollution levels in agreement with expectations (e.g., high levels on or near busy roadways and lower levels in background residential areas and parks). Our findings suggest that the low cost, personal sensors have potential to reduce exposure measurement error in epidemiological studies and provide valid data for citizen science studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Risk estimation by exposure to PM10 particles in the Toluca Valley

    International Nuclear Information System (INIS)

    Flores R, J.H.; Pena G, P.; Balcazar, M.; Lopez M, A.; Morelos M, J.

    2007-01-01

    Full text: Risk estimation to PM10 in the Toluca valley and surrounding areas was estimated, for several return periods, evaluating the occurrence probability to several interval times (1, 5, 10, 12.5, 15, 17.5 and 20 years) using the extreme values of the Gumbel-1 distribution; those intervals were employed to predict and analyze the behaviour of maximum contaminant concentrations in the study region. A high degree of risk to health due to the mean concentration of these particles is obtained from statistical considerations. The evaluation took into consideration the eight monitoring years from the Automatic Atmospheric Monitoring Network (RAMAT) and its output predicts, if present conditions maintain, this statistical relation remain invariant between the next 20 years. Such particles affect the human respiratory system, besides, present a carcinogenic potential due to the volume of hydrocarbons combustion to the atmosphere. (Author)

  2. Polybrominated diphenyl ethers (PBDEs) in US meat and poultry: 2012-13 levels, trends and estimated consumer exposures.

    Science.gov (United States)

    Lupton, Sara J; Hakk, Heldur

    2017-09-01

    Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants whose use has contaminated foods and caused subsequent human exposures. To address the issue of possible human exposure, samples from a 2012-13 US meat and poultry (beef, pork, chicken, turkey) study were analysed for seven PBDEs. The mean summed concentrations of the seven BDE congeners (ΣPBDE) from beef, pork, chicken and turkey were 0.40, 0.36, 0.19, and 0.76 ng g -1 lipid weight (lw). The range of ΣPBDEs for all meat classes was 0.01-15.78 ng g -1 lw. A comparison of this study with a 2007-08 study revealed a decline in the median ΣPBDEs for all four meat classes, a reduction of 25.9% to 70.0%, with pork, chicken and turkey PBDE residues being statistically lower relative to the 2007-08 study. BDEs 47 and 99 contributed the most to the ΣPBDE concentrations, indicating likely animal exposures to the penta-BDE formulation. Based on the reported data an estimate of US consumer daily intake of PBDEs from meat and poultry was 6.42 ng day -1 .

  3. Quantitative microbial risk assessment to estimate the health risk from exposure to noroviruses in polluted surface water in South Africa.

    Science.gov (United States)

    Van Abel, Nicole; Mans, Janet; Taylor, Maureen B

    2017-10-01

    This study assessed the risks posed by noroviruses (NoVs) in surface water used for drinking, domestic, and recreational purposes in South Africa (SA), using a quantitative microbial risk assessment (QMRA) methodology that took a probabilistic approach coupling an exposure assessment with four dose-response models to account for uncertainty. Water samples from three rivers were found to be contaminated with NoV GI (80-1,900 gc/L) and GII (420-9,760 gc/L) leading to risk estimates that were lower for GI than GII. The volume of water consumed and the probabilities of infection were lower for domestic (2.91 × 10 -8 to 5.19 × 10 -1 ) than drinking water exposures (1.04 × 10 -5 to 7.24 × 10 -1 ). The annual probabilities of illness varied depending on the type of recreational water exposure with boating (3.91 × 10 -6 to 5.43 × 10 -1 ) and swimming (6.20 × 10 -6 to 6.42 × 10 -1 ) being slightly greater than playing next to/in the river (5.30 × 10 -7 to 5.48 × 10 -1 ). The QMRA was sensitive to the choice of dose-response model. The risk of NoV infection or illness from contaminated surface water is extremely high in SA, especially for lower socioeconomic individuals, but is similar to reported risks from limited international studies.

  4. Estimating annoyance to calculated wind turbine shadow flicker is improved when variables associated with wind turbine noise exposure are considered.

    Science.gov (United States)

    Voicescu, Sonia A; Michaud, David S; Feder, Katya; Marro, Leonora; Than, John; Guay, Mireille; Denning, Allison; Bower, Tara; van den Berg, Frits; Broner, Norm; Lavigne, Eric

    2016-03-01

    The Community Noise and Health Study conducted by Health Canada included randomly selected participants aged 18-79 yrs (606 males, 632 females, response rate 78.9%), living between 0.25 and 11.22 km from operational wind turbines. Annoyance to wind turbine noise (WTN) and other features, including shadow flicker (SF) was assessed. The current analysis reports on the degree to which estimating high annoyance to wind turbine shadow flicker (HAWTSF) was improved when variables known to be related to WTN exposure were also considered. As SF exposure increased [calculated as maximum minutes per day (SFm)], HAWTSF increased from 3.8% at 0 ≤ SFm wind turbine-related features, concern for physical safety, and noise sensitivity. Reported dizziness was also retained in the final model at p = 0.0581. Study findings add to the growing science base in this area and may be helpful in identifying factors associated with community reactions to SF exposure from wind turbines.

  5. Measuring radiation exposure during percutaneous drainages: can shoulder dosemeters be used to estimate finger doses?

    International Nuclear Information System (INIS)

    Vehmas, Tapio; Tikkanen, Heikki

    1992-01-01

    To assess the need for extra finger dosemeters, radiologists' and assistants' radiation exposure at both shoulders and at the third fingers of both hands were recorded using thermoluminescent dosemeters during 27 interventional drainage procedures. Under couch screening was used. Mean dose rates were calculated by dividing dose by screening time. The radiologists' bilateral finger dose rates did not correlate with each other; nor did dose rates between the left shoulder and the right hand. The radiologists' dose rates at both shoulders, correlated with each other, as did shoulder dose rates with dose rates at the ispilateral hand. The right shoulder dose rates correlated with the left hand dose rates. The assistants' dose rates at places of measurement showed significant correlations with each other. (Author)

  6. Bulgarian Emergency Response System (BERS) in case of nuclear accident with exposure doses estimation

    Energy Technology Data Exchange (ETDEWEB)

    Syrakov, D.; Prodanova, M.; Slavov, K.; Veleva, B.

    2015-07-01

    A PC-oriented Emergency Response System in case of nuclear accident (BERS) is developed and works operationally in the National Institute of Meteorology and Hydrology (NIMH). The creation and development of BERS was highly stimulated by the ETEX (European Tracer Experiment) project. BERS comprises two main parts - the operational and the accidental ones. The operational part, run automatically every 12 hours, prepares the input meteorological file used by both trajectory and dispersion models, runs the trajectory models, visualizes the results and uploads the maps of trajectories to a dedicated web-site. The accidental part is activated manually when a real radioactive releases occur or during emergency exercises. Its core is the Bulgarian dispersion models EMAP. Outputs are concentration, accumulated deposition and selected doses fields. In the paper, the BERS overall structure is described and examples of its products are presented. Key words: nuclear accident, emergency response, early warning system, air dispersion models, radioactive exposure dose. (Author)

  7. Hospital and clinic survey estimates of medical X-ray exposure in Hiroshima and Nagasaki, 2

    International Nuclear Information System (INIS)

    Antoku, Shigetoshi; Hoshi, Masaharu; Sawada, Shozo; Russell, W.J.

    1987-07-01

    The technical factors used during radiological examinations performed in Hiroshima and Nagasaki medical institutions were analyzed. The most frequently performed examination was chest radiography, followed by upper GI series. More than half the radiographic exposures were from upper GI series due to the many spot films made during fluoroscopy. Comparison of the present survey results with those of a previous one showed that relatively high kVp, low mAs and mA, and smaller field sizes are now more widely used. Though there have been decreased in fluoroscopy times and tube currents over the past 10 years, the numbers of spot films used have increased. Based on these technical factors, tables of organ doses from fluoroscopic examinations were compiled. (author)

  8. Terrestrial Gamma Radiation Exposure Measurement and Risk Estimates in the Environments of Major Industries In Ota, Nigeria

    Directory of Open Access Journals (Sweden)

    Abodunrin Oluwasayo Peter

    2016-11-01

    Full Text Available When fast estimates are required, the in-situ method is more appropriate as this allows for quick results; preventing further exposure of the public and permitting quick intervention. Measurements of the terrestrial gamma radiation exposure have been carried out in the environments of major industries in Ota using a portable survey meter. The motivation for this study resulted from the uncertainty in the general public opinion on the effect of the presence, and activities of some of these industries in their environment. Measurements were taken twice daily within the vicinity of each industry to determine the dose levels. The mean values obtained range from 0.11 – 1.80 µSv/h. These values are within the results obtained from normal background areas except for site number 10. Annual effective dose values range from 0.25 – 5.21 mSv with a mean value of 1.21 mSv. Routine activities in some of these environments may have contributed significantly to the ambient natural background radiation resulting in high values as obtained in some of these locations. The total risks disparately estimated for cancer and genetic effects resulting from the results obtained range from 0.17 x 10-4 – 3.80 x 10-4 with a mean value of 0.94 x 10-4. These levels are within the range of the average annual risk for accidental death for all industries.

  9. Explicit formula of finite difference method to estimate human peripheral tissue temperatures during exposure to severe cold stress.

    Science.gov (United States)

    Khanday, M A; Hussain, Fida

    2015-02-01

    During cold exposure, peripheral tissues undergo vasoconstriction to minimize heat loss to preserve the maintenance of a normal core temperature. However, vasoconstricted tissues exposed to cold temperatures are susceptible to freezing and frostbite-related tissue damage. Therefore, it is imperative to establish a mathematical model for the estimation of tissue necrosis due to cold stress. To this end, an explicit formula of finite difference method has been used to obtain the solution of Pennes' bio-heat equation with appropriate boundary conditions to estimate the temperature profiles of dermal and subdermal layers when exposed to severe cold temperatures. The discrete values of nodal temperature were calculated at the interfaces of skin and subcutaneous tissues with respect to the atmospheric temperatures of 25 °C, 20 °C, 15 °C, 5 °C, -5 °C and -10 °C. The results obtained were used to identify the scenarios under which various degrees of frostbite occur on the surface of skin as well as the dermal and subdermal areas. The explicit formula of finite difference method proposed in this model provides more accurate predictions as compared to other numerical methods. This model of predicting tissue temperatures provides researchers with a more accurate prediction of peripheral tissue temperature and, hence, the susceptibility to frostbite during severe cold exposure. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)<