Auditory Effects of Exposure to Noise and Solvents: A Comparative Study

PubMed Central

Lobato, Diolen Conceição Barros; Lacerda, Adriana Bender Moreira De; Gonçalves, Cláudia Giglio De Oliveira; Coifman, Herton

2013-01-01

Introduction Industry workers are exposed to different environmental risk agents that, when combined, may potentiate risks to hearing. Objective To evaluate the effects of the combined exposure to noise and solvents on hearing in workers. Methods A transversal retrospective cohort study was performed through documentary analysis of an industry. The sample (n = 198) was divided into four groups: the noise group (NG), exposed only to noise; the noise and solvents group (NSG), exposed to noise and solvents; the noise control group and noise and solvents control group (CNS), no exposure. Results The NG showed 16.66% of cases suggestive of bilateral noise-induced hearing loss and NSG showed 5.26%. The NG and NSG had worse thresholds than their respective control groups. Females were less susceptible to noise than males; however, when simultaneously exposed to solvents, hearing was affected in a similar way, resulting in significant differences (p < 0.05). The 40- to 49-year-old age group was significantly worse (p < 0.05) in the auditory thresholds in the NSG compared with the CNS. Conclusion The results observed in this study indicate that simultaneous exposure to noise and solvents can damage the peripheral auditory system. PMID:25992079

Fumonisin B1 Toxicity in Grower-Finisher Pigs: A Comparative Analysis of Genetically Engineered Bt Corn and non-Bt Corn by Using Quantitative Dietary Exposure Assessment Modeling

PubMed Central

Delgado, James E.; Wolt, Jeffrey D.

2011-01-01

In this study, we investigate the long-term exposure (20 weeks) to fumonisin B1 (FB1) in grower-finisher pigs by conducting a quantitative exposure assessment (QEA). Our analytical approach involved both deterministic and semi-stochastic modeling for dietary comparative analyses of FB1 exposures originating from genetically engineered Bacillus thuringiensis (Bt)-corn, conventional non-Bt corn and distiller’s dried grains with solubles (DDGS) derived from Bt and/or non-Bt corn. Results from both deterministic and semi-stochastic demonstrated a distinct difference of FB1 toxicity in feed between Bt corn and non-Bt corn. Semi-stochastic results predicted the lowest FB1 exposure for Bt grain with a mean of 1.5 mg FB1/kg diet and the highest FB1 exposure for a diet consisting of non-Bt grain and non-Bt DDGS with a mean of 7.87 mg FB1/kg diet; the chronic toxicological incipient level of concern is 1.0 mg of FB1/kg of diet. Deterministic results closely mirrored but tended to slightly under predict the mean result for the semi-stochastic analysis. This novel comparative QEA model reveals that diet scenarios where the source of grain is derived from Bt corn presents less potential to induce FB1 toxicity than diets containing non-Bt corn. PMID:21909298

Different profiles of carcinogen exposure in Chinese compared with US cigarette smokers.

PubMed

Benowitz, Neal L; Gan, Quan; Goniewicz, Maciej L; Lu, Wei; Xu, Jiying; Li, Xinjian; Jacob, Peyton; Glantz, Stanton

2015-12-01

Differences in carcinogen exposure from different cigarette products could contribute to differences in smoking-associated cancer incidence among Chinese compared with US smokers. Urine concentrations of metabolites of nicotine, the tobacco-specific nitrosamine (TSNA) 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and polycyclic aromatic hydrocarbon metabolites (PAHs) were compared in 238 Chinese and 203 US daily smokers. Comparing Chinese versus US smokers, daily nicotine intake and nicotine intake per cigarette smoked were found to be similar. When normalised for cigarettes per day, urine NNAL excretion was fourfold higher in US smokers, while the excretion of urine metabolites of the PAHs fluorene, phenanthrene and pyrene metabolites was 50% to fourfold higher in Chinese smokers (all, p<0.0001). Similar results were seen when NNAL and PAHs excretion was normalised for daily nicotine intake. Patterns of carcinogen exposure differ, with lower exposure to TSNA and higher exposure to PAHs in Chinese compared with US smokers. These results most likely reflect country differences in cigarette tobacco blends and manufacturing processes, as well as different environmental exposures. NCT00264342. 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/

Virtual reality exposure therapy in anxiety disorders: a quantitative meta-analysis.

PubMed

Opriş, David; Pintea, Sebastian; García-Palacios, Azucena; Botella, Cristina; Szamosközi, Ştefan; David, Daniel

2012-02-01

Virtual reality exposure therapy (VRET) is a promising intervention for the treatment of the anxiety disorders. The main objective of this meta-analysis is to compare the efficacy of VRET, used in a behavioral or cognitive-behavioral framework, with that of the classical evidence-based treatments, in anxiety disorders. A comprehensive search of the literature identified 23 studies (n = 608) that were included in the final analysis. The results show that in the case of anxiety disorders, (1) VRET does far better than the waitlist control; (2) the post-treatment results show similar efficacy between the behavioral and the cognitive behavioral interventions incorporating a virtual reality exposure component and the classical evidence-based interventions, with no virtual reality exposure component; (3) VRET has a powerful real-life impact, similar to that of the classical evidence-based treatments; (4) VRET has a good stability of results over time, similar to that of the classical evidence-based treatments; (5) there is a dose-response relationship for VRET; and (6) there is no difference in the dropout rate between the virtual reality exposure and the in vivo exposure. Implications are discussed. © 2011 Wiley Periodicals, Inc.

A TIERED APPROACH TO PERFORMING UNCERTAINTY ANALYSIS IN CONDUCTING EXPOSURE ANALYSIS FOR CHEMICALS

EPA Science Inventory

The WHO/IPCS draft Guidance Document on Characterizing and Communicating Uncertainty in Exposure Assessment provides guidance on recommended strategies for conducting uncertainty analysis as part of human exposure analysis. Specifically, a tiered approach to uncertainty analysis ...

Enhanced UV exposure on a ski-field compared with exposures at sea level.

PubMed

Allen, Martin; McKenzie, Richard

2005-05-01

Personal erythemal UV monitoring badges, which were developed to monitor the UV exposure of school children, were used to measure UV exposures received by one of the authors (MA) at the Mt Hutt ski-field, in New Zealand. These were then compared with measurements taken at the same times from a nearby sea level site in Christchurch city. The badges were designed to give instantaneous readings of erythemally-weighted (i.e., "sun burning") UV radiation and were cross-calibrated against meteorological grade UV instruments maintained by the National Institute of Water & Atmospheric Research (NIWA). All skiing and calibration days were clear and almost exclusively cloud free. It was found that the UV maxima for horizontal surfaces at the ski-field (altitude approximately 2 km) were 20-30% greater than at the low altitude site. Larger differences between the sites were observed when the sensor was oriented perpendicular to the sun. The personal doses of UV received by a sensor on the skier's lapel during two days of skiing activity were less than those received by a stationary detector on a horizontal surface near sea level. The exposures depended strongly on the time of year, and in mid-October the maximum UV intensity on the ski-field was 60% greater than in mid-September. The UV exposure levels experienced during skiing were smaller than the summer maxima at low altitudes.

Comparative Probabilistic Assessment of Occupational Pesticide Exposures Based on Regulatory Assessments

PubMed Central

Pouzou, Jane G.; Cullen, Alison C.; Yost, Michael G.; Kissel, John C.; Fenske, Richard A.

2018-01-01

Implementation of probabilistic analyses in exposure assessment can provide valuable insight into the risks of those at the extremes of population distributions, including more vulnerable or sensitive subgroups. Incorporation of these analyses into current regulatory methods for occupational pesticide exposure is enabled by the exposure data sets and associated data currently used in the risk assessment approach of the Environmental Protection Agency (EPA). Monte Carlo simulations were performed on exposure measurements from the Agricultural Handler Exposure Database and the Pesticide Handler Exposure Database along with data from the Exposure Factors Handbook and other sources to calculate exposure rates for three different neurotoxic compounds (azinphos methyl, acetamiprid, emamectin benzoate) across four pesticide-handling scenarios. Probabilistic estimates of doses were compared with the no observable effect levels used in the EPA occupational risk assessments. Some percentage of workers were predicted to exceed the level of concern for all three compounds: 54% for azinphos methyl, 5% for acetamiprid, and 20% for emamectin benzoate. This finding has implications for pesticide risk assessment and offers an alternative procedure that may be more protective of those at the extremes of exposure than the current approach. PMID:29105804

Skin analysis following dermal exposure to kerosene in rats: the effects of postmortem exposure and fire.

PubMed

Hieda, Yoko; Tsujino, Yoshio; Xue, Yuying; Takayama, Koji; Fujihara, Junko; Kimura, Kojiro; Dekio, Satoshi

2004-02-01

To evaluate the usefulness of skin analysis for the forensic examination of cases involving postmortem dermal exposure to kerosene and/or fire, an experimental study using rats was performed. Rats received dermal exposure to kerosene before or after death, and the effect of fire was determined by burning an area of exposed skin after death. Kerosene concentrations in skin and blood were determined by gas chromatography-mass spectrometry and microscopic observation was performed for skin samples. No differences were observed in skin kerosene levels between antemortem and postmortem exposure. Kerosene concentrations in mildly burned skin where the stratum corneum (SC) was retained were approximately 84% compared to those in non-burned exposed skin, whereas concentrations in severely burned skin where the SC was almost completely burned off were 28% of non-burned skin. Even in non-exposed control skin 14% of the original kerosene concentrations could be detected, which was considered to be caused by contamination during the experimental protocol combined with kerosene's property of a high affinity for the SC. These results suggest that (1) skin analysis is useful in estimating the type of petroleum product involved in crimes or accidents even for postmortem exposure, (2) whether the SC is retained or not primarily determined the kerosene levels in burned skin, and (3) attention must be paid to evaluate the results obtained from skin samples in the light of the circumstances surrounding the case.

Measuring exposure in Hurricane Katrina: a meta-analysis and an integrative data analysis.

PubMed

Chan, Christian S; Rhodes, Jean E

2014-01-01

To date there is no consensus on the operationalization of exposure severity in the study of the impact of natural disasters. This is problematic because incomplete and inconsistent measurement of exposure limits the internal and external validity of disaster studies. The current paper examined the predictive validity of severity measures in two interrelated studies of Hurricane Katrina survivors. First, in a meta-analysis of eight studies that measured both exposure severity and posttraumatic stress, the effect size was estimated to be r = .266. The moderating effects of sample and study characteristics were examined and we found that minority status and number of stressors assessed were significant moderators. Second, in an integrative data analysis of five independent samples of Hurricane Katrina survivors, the impact of specific disaster-related stressors on mental health was compared. Threat to physical integrity of self and others were found to have the strongest association with posttraumatic stress (PTS) and general psychological distress (GPD). The lack of basic necessities, such as food, water, and medical care, and loss of pet were also found to be strongly associated with both PTS and GPD. The results from the two studies are integrated and their implication for disaster research and relief are discussed.

Measuring Exposure in Hurricane Katrina: A Meta-Analysis and an Integrative Data Analysis

PubMed Central

Chan, Christian S.; Rhodes, Jean E.

2014-01-01

To date there is no consensus on the operationalization of exposure severity in the study of the impact of natural disasters. This is problematic because incomplete and inconsistent measurement of exposure limits the internal and external validity of disaster studies. The current paper examined the predictive validity of severity measures in two interrelated studies of Hurricane Katrina survivors. First, in a meta-analysis of eight studies that measured both exposure severity and posttraumatic stress, the effect size was estimated to be r = .266. The moderating effects of sample and study characteristics were examined and we found that minority status and number of stressors assessed were significant moderators. Second, in an integrative data analysis of five independent samples of Hurricane Katrina survivors, the impact of specific disaster-related stressors on mental health was compared. Threat to physical integrity of self and others were found to have the strongest association with posttraumatic stress (PTS) and general psychological distress (GPD). The lack of basic necessities, such as food, water, and medical care, and loss of pet were also found to be strongly associated with both PTS and GPD. The results from the two studies are integrated and their implication for disaster research and relief are discussed. PMID:24713851

Measurement methods for human exposure analysis.

PubMed Central

Lioy, P J

1995-01-01

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

Comparative analysis of radioecological monitoring dosimeters

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

Sobolev, A.I.; Pol`skii, O.G.; Shanin, O.B.

1995-03-01

This paper describes comparative estimates of radiation doses measured by two types of thermoluminescence dosimeters and two types of background radiation radiometers. The dosimetry systems were tested by simultaneously recording background radiation and standard radiation sources at a radioactive waste storage facility. Statistical analysis of the measurement results is summarized. The maximum recorded exposure dose rate for the experiment was 19 microrads per hour. The DTK-2 dosimeter overestimated dose rates by 6 to 43% and the DTU-2 dosimeter underestimated dose rates by 7 to 21%. Both devices are recommended for radioecological monitoring in populated areas. 4 refs., 3 figs., 5more » tabs.« less

Virtual reality treatment versus exposure in vivo: a comparative evaluation in acrophobia.

PubMed

Emmelkamp, P M G; Krijn, M; Hulsbosch, A M; de Vries, S; Schuemie, M J; van der Mast, C A P G

2002-05-01

The aim of the present study was to evaluate the effectiveness of low-budget virtual reality (VR) exposure versus exposure in vivo in a between-group design in 33 patients suffering from acrophobia. The virtual environments used in treatment were exactly copied from the real environments used in the exposure in vivo program. VR exposure was found to be as effective as exposure in vivo on anxiety and avoidance as measured with the Acrophobia Questionnaire (AQ), the Attitude Towards Heights Questionnaire (ATHQ) and the Behavioral Avoidance Test (BAT). Results were maintained up to six months follow-up. The present study shows that VR exposure can be effective with relatively cheap hardware and software on stand-alone computers currently on the market. Further studies into the effectiveness of VR exposure are recommended in other clinical groups as agoraphobics and social phobics and studies in which VR exposure is compared with more emerging virtual worlds as presented in CAVE-type systems.

Stratified probabilistic bias analysis for BMI-related exposure misclassification in postmenopausal women.

PubMed

Banack, Hailey R; Stokes, Andrew; Fox, Matthew P; Hovey, Kathleen M; Cespedes-Feliciano, Elizabeth M; LeBlanc, Erin; Bird, Chloe; Caan, Bette J; Kroenke, Candyce H; Allison, Matthew A; Going, Scott B; Snetslaar, Linda; Cheng, Ting-Yuan David; Chlebowski, Rowan T; Stefanick, Marcia L; LaMonte, Michael J; Wactawski-Wende, Jean

2018-06-01

There is widespread concern about the use of body mass index (BMI) to define obesity status in postmenopausal women because it may not accurately represent an individual's true obesity status. The objective of the present study is to examine and adjust for exposure misclassification bias from using an indirect measure of obesity (BMI) compared with a direct measure of obesity (percent body fat). We used data from postmenopausal non-Hispanic black and non-Hispanic white women in the Women's Health Initiative (WHI; n=126,459). Within the WHI, a sample of 11,018 women were invited to participate in a sub-study involving dual-energy x-ray absorptiometry (DXA) scans. We examined indices of validity comparing BMI-defined obesity (≥30kg/m) with obesity defined by percent body fat. We then used probabilistic bias analysis models stratified by age and race to explore the effect of exposure misclassification on the obesity-mortality relationship. Validation analyses highlight that using a BMI cutpoint of 30 kg/m to define obesity in postmenopausal women is associated with poor validity. There were notable differences in sensitivity by age and race. Results from the stratified bias analysis demonstrated that failing to adjust for exposure misclassification bias results in attenuated estimates of the obesity-mortality relationship. For example, in non-Hispanic white women age 50-59, the conventional risk difference was 0.017 (95% CI 0.01, 0.023) and the bias-adjusted risk difference was 0.035 (95% SI 0.028, 0.043). These results demonstrate the importance of using quantitative bias analysis techniques to account for non-differential exposure misclassification of BMI-defined obesity.

Occupational COPD and job exposure matrices: a systematic review and meta-analysis

PubMed Central

Sadhra, Steven; Kurmi, Om P; Sadhra, Sandeep S; Lam, Kin Bong Hubert; Ayres, Jon G

2017-01-01

Background The association between occupational exposure and COPD reported previously has mostly been derived from studies relying on self-reported exposure to vapors, gases, dust, or fumes (VGDF), which could be subjective and prone to biases. The aim of this study was to assess the strength of association between exposure and COPD from studies that derived exposure by job exposure matrices (JEMs). Methods A systematic search of JEM-based occupational COPD studies published between 1980 and 2015 was conducted in PubMed and EMBASE, followed by meta-analysis. Meta-analysis was performed using a random-effects model, with results presented as a pooled effect estimate with 95% confidence intervals (CIs). The quality of study (risk of bias and confounding) was assessed by 13 RTI questionnaires. Heterogeneity between studies and its possible sources were assessed by Egger test and meta-regression, respectively. Results In all, 61 studies were identified and 29 were included in the meta-analysis. Based on JEM-based studies, there was 22% (pooled odds ratio =1.22; 95% CI 1.18–1.27) increased risk of COPD among those exposed to airborne pollutants arising from occupation. Comparatively, higher risk estimates were obtained for general populations JEMs (based on expert consensus) than workplace-based JEM were derived using measured exposure data (1.26; 1.20–1.33 vs 1.14; 1.10–1.19). Higher risk estimates were also obtained for self-reported exposure to VGDF than JEMs-based exposure to VGDF (1.91; 1.72–2.13 vs 1.10; 1.06–1.24). Dusts, particularly biological dusts (1.33; 1.17–1.51), had the highest risk estimates for COPD. Although the majority of occupational COPD studies focus on dusty environments, no difference in risk estimates was found for the common forms of occupational airborne pollutants. Conclusion Our findings highlight the need to interpret previous studies with caution as self-reported exposure to VGDF may have overestimated the risk of occupational

Comparing children's GPS tracks with geospatial proxies for exposure to junk food.

PubMed

Sadler, Richard C; Gilliland, Jason A

2015-01-01

Various geospatial techniques have been employed to estimate children's exposure to environmental cardiometabolic risk factors, including junk food. But many studies uncritically rely on exposure proxies which differ greatly from actual exposure. Misrepresentation of exposure by researchers could lead to poor decisions and ineffective policymaking. This study conducts a GIS-based analysis of GPS tracks--'activity spaces'--and 21 proxies for activity spaces (e.g. buffers, container approaches) for a sample of 526 children (ages 9-14) in London, Ontario, Canada. These measures are combined with a validated food environment database (including fast food and convenience stores) to create a series of junk food exposure estimates and quantify the errors resulting from use of different proxy methods. Results indicate that exposure proxies consistently underestimate exposure to junk foods by as much as 68%. This underestimation is important to policy development because children are exposed to more junk food than estimated using typical methods. Copyright © 2015 Elsevier Ltd. All rights reserved.

A new mask exposure and analysis facility

NASA Astrophysics Data System (ADS)

te Sligte, Edwin; Koster, Norbert; Deutz, Alex; Staring, Wilbert

2014-10-01

The introduction of ever higher source powers in EUV systems causes increased risks for contamination and degradation of EUV masks and pellicles. Appropriate testing can help to inventory and mitigate these risks. To this end, we propose EBL2: a laboratory EUV exposure system capable of operating at high EUV powers and intensities, and capable of exposing and analyzing EUV masks. The proposed system architecture is similar to the EBL system which has been operated jointly by TNO and Carl Zeiss SMT since 2005. EBL2 contains an EUV Beam Line, in which samples can be exposed to EUV irradiation in a controlled environment. Attached to this Beam Line is an XPS system, which can be reached from the Beam Line via an in-vacuum transfer system. This enables surface analysis of exposed masks without breaking vacuum. Automated handling with dual pods is foreseen so that exposed EUV masks will still be usable in EUV lithography tools to assess the imaging impact of the exposure. Compared to the existing system, large improvements in EUV power, intensity, reliability, and flexibility are proposed. Also, in-situ measurements by e.g. ellipsometry is foreseen for real time monitoring of the sample condition. The system shall be equipped with additional ports for EUVR or other analysis tools. This unique facility will be open for external customers and other research groups.

Symbolic Analysis of Heart Rate Variability During Exposure to Musical Auditory Stimulation.

PubMed

Vanderlei, Franciele Marques; de Abreu, Luiz Carlos; Garner, David Matthew; Valenti, Vitor Engrácia

2016-01-01

In recent years, the application of nonlinear methods for analysis of heart rate variability (HRV) has increased. However, studies on the influence of music on cardiac autonomic modulation in those circumstances are rare. The research team aimed to evaluate the acute effects on HRV of selected auditory stimulation by 2 musical styles, measuring the results using nonlinear methods of analysis: Shannon entropy, symbolic analysis, and correlation-dimension analysis. Prospective control study in which the volunteers were exposed to music and variables were compared between control (no auditory stimulation) and during exposure to music. All procedures were performed in a sound-proofed room at the Faculty of Science and Technology at São Paulo State University (UNESP), São Paulo, Brazil. Participants were 22 healthy female students, aged between 18 and 30 y. Prior to the actual intervention, the participants remained at rest for 20 min, and then they were exposed to one of the selected types of music, either classical baroque (64-84 dB) or heavy-metal (75-84 dB). Each musical session lasted a total of 5 min and 15 s. At a point occurring up to 1 wk after that day, the participants listened to the second type of music. The 2 types of music were delivered in a random sequence that depended on the group to which the participant was assigned. The study analyzed the following HRV indices through Shannon entropy; symbolic analysis-0V%, 1V%, 2LV%, and 2ULV%; and correlation-dimension analysis. During exposure to auditory stimulation by heavy-metal or classical baroque music, the study established no statistically significant variations regarding the indices for the Shannon entropy; the symbolic analysis-0V%, 1V%, and 2ULV%; and the correlation-dimension analysis. However, during heavy-metal music, the 2LV% index in the symbolic analysis was reduced compared with the controls. Auditory stimulation with the heavy-metal music reduced the parasympathetic modulation of HRV

Air-liquid interface exposure to aerosols of poorly soluble nanomaterials induces different biological activation levels compared to exposure to suspensions.

PubMed

Loret, Thomas; Peyret, Emmanuel; Dubreuil, Marielle; Aguerre-Chariol, Olivier; Bressot, Christophe; le Bihan, Olivier; Amodeo, Tanguy; Trouiller, Bénédicte; Braun, Anne; Egles, Christophe; Lacroix, Ghislaine

2016-11-03

Recently, much progress has been made to develop more physiologic in vitro models of the respiratory system and improve in vitro simulation of particle exposure through inhalation. Nevertheless, the field of nanotoxicology still suffers from a lack of relevant in vitro models and exposure methods to predict accurately the effects observed in vivo, especially after respiratory exposure. In this context, the aim of our study was to evaluate if exposing pulmonary cells at the air-liquid interface to aerosols of inhalable and poorly soluble nanomaterials generates different toxicity patterns and/or biological activation levels compared to classic submerged exposures to suspensions. Three nano-TiO 2 and one nano-CeO 2 were used. An exposure system was set up using VitroCell® devices to expose pulmonary cells at the air-liquid interface to aerosols. A549 alveolar cells in monocultures or in co-cultures with THP-1 macrophages were exposed to aerosols in inserts or to suspensions in inserts and in plates. Submerged exposures in inserts were performed, using similar culture conditions and exposure kinetics to the air-liquid interface, to provide accurate comparisons between the methods. Exposure in plates using classical culture and exposure conditions was performed to provide comparable results with classical submerged exposure studies. The biological activity of the cells (inflammation, cell viability, oxidative stress) was assessed at 24 h and comparisons of the nanomaterial toxicities between exposure methods were performed. Deposited doses of nanomaterials achieved using our aerosol exposure system were sufficient to observe adverse effects. Co-cultures were more sensitive than monocultures and biological responses were usually observed at lower doses at the air-liquid interface than in submerged conditions. Nevertheless, the general ranking of the nanomaterials according to their toxicity was similar across the different exposure methods used. We showed that

Rating locomotive crew diesel emission exposure profiles using statistics and Bayesian Decision Analysis.

PubMed

Hewett, Paul; Bullock, William H

2014-01-01

For more than 20 years CSX Transportation (CSXT) has collected exposure measurements from locomotive engineers and conductors who are potentially exposed to diesel emissions. The database included measurements for elemental and total carbon, polycyclic aromatic hydrocarbons, aromatics, aldehydes, carbon monoxide, and nitrogen dioxide. This database was statistically analyzed and summarized, and the resulting statistics and exposure profiles were compared to relevant occupational exposure limits (OELs) using both parametric and non-parametric descriptive and compliance statistics. Exposure ratings, using the American Industrial Health Association (AIHA) exposure categorization scheme, were determined using both the compliance statistics and Bayesian Decision Analysis (BDA). The statistical analysis of the elemental carbon data (a marker for diesel particulate) strongly suggests that the majority of levels in the cabs of the lead locomotives (n = 156) were less than the California guideline of 0.020 mg/m(3). The sample 95th percentile was roughly half the guideline; resulting in an AIHA exposure rating of category 2/3 (determined using BDA). The elemental carbon (EC) levels in the trailing locomotives tended to be greater than those in the lead locomotive; however, locomotive crews rarely ride in the trailing locomotive. Lead locomotive EC levels were similar to those reported by other investigators studying locomotive crew exposures and to levels measured in urban areas. Lastly, both the EC sample mean and 95%UCL were less than the Environmental Protection Agency (EPA) reference concentration of 0.005 mg/m(3). With the exception of nitrogen dioxide, the overwhelming majority of the measurements for total carbon, polycyclic aromatic hydrocarbons, aromatics, aldehydes, and combustion gases in the cabs of CSXT locomotives were either non-detects or considerably less than the working OELs for the years represented in the database. When compared to the previous American

Summary of ionizing radiation analysis on the Long Duration Exposure Facility

NASA Technical Reports Server (NTRS)

Parnell, T. A.

1991-01-01

The Ionizing Radiation Special Investigation Group (IRSIG) for the Long Duration Exposure Facility (LDEF) was established to perform radiation measurements and analysis not planned in the original experiments, and to assure availability of LDEF analysis results in a form useful to future missions. The IRSIG has organized extensive induced radioactivity measurements throughout LDEF, and a comprehensive program to compare the LDEF radiation measurements to values calculated using environment models. The activities and present status of the Group is described. The ionizing radiation results presented is summarized.

Radiation exposure of contrast-enhanced spectral mammography compared with full-field digital mammography.

PubMed

Jeukens, Cécile R L P N; Lalji, Ulrich C; Meijer, Eduard; Bakija, Betina; Theunissen, Robin; Wildberger, Joachim E; Lobbes, Marc B I

2014-10-01

Contrast-enhanced spectral mammography (CESM) shows promising initial results but comes at the cost of increased dose as compared with full-field digital mammography (FFDM). We aimed to quantitatively assess the dose increase of CESM in comparison with FFDM. Radiation exposure-related data (such as kilovoltage, compressed breast thickness, glandularity, entrance skin air kerma (ESAK), and average glandular dose (AGD) were retrieved for 47 CESM and 715 FFDM patients. All examinations were performed on 1 mammography unit. Radiation dose values reported by the unit were validated by phantom measurements. Descriptive statistics of the patient data were generated using a statistical software package. Dose values reported by the mammography unit were in good qualitative agreement with those of phantom measurements. Mean ESAK was 10.5 mGy for a CESM exposure and 7.46 mGy for an FFDM exposure. Mean AGD for a CESM exposure was 2.80 mGy and 1.55 mGy for an FFDM exposure. Compared with our institutional FFDM, the AGD of a single CESM exposure is increased by 1.25 mGy (+81%), whereas ESAK is increased by 3.07 mGy (+41%). Dose values of both techniques meet the recommendations for maximum dose in mammography.

Fault tree analysis for exposure to refrigerants used for automotive air conditioning in the United States.

PubMed

Jetter, J J; Forte, R; Rubenstein, R

2001-02-01

A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air-conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air-conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air-conditioning systems, absent a means of mitigating exposure.

Association Between Cd Exposure and Risk of Prostate Cancer: A PRISMA-Compliant Systematic Review and Meta-Analysis.

PubMed

Ju-Kun, Song; Yuan, Dong-Bo; Rao, Hao-Fu; Chen, Tian-Fei; Luan, Bo-Shi; Xu, Xiao-Ming; Jiang, Fu-Neng; Zhong, Wei-De; Zhu, Jian-Guo

2016-02-01

Several observational studies on the association between Cd exposure and risk of prostate cancer have yielded inconsistent results. To address this issue, we conducted a meta-analysis to evaluate the correlation between Cd exposure and risk of prostate cancer.Relevant studies in PubMed and Embase databases were retrieved until October 2015. We compared the highest and lowest meta-analyses to quantitatively evaluate the relationship between Cd exposure and risk of prostate cancer. Summary estimates were obtained using a random-effects model.In the general population, high Cd exposure was not associated with increased prostate cancer (OR 1.21; 95% CI 0.91-1.64), whereas the combined standardized mortality ratio of the association between Cd exposure and risk of prostate cancer was 1.66 (95% CI 1.10-2.50) in populations exposed to occupational Cd. In addition, high D-Cd intake (OR 1.07; 95% CI 0.96-1.20) and U-Cd concentration (OR 0.86; 95% CI 0.48-1.55) among the general population was not related to the increased risk of prostate cancer. In the dose analysis, the summary relative risk was 1.07 (95% CI 0.73-1.57) for each 0.5 μg/g creatinine increase in U-Cd and 1.02 (95% CI 0.99-1.06) for each 10 μg/day increase of dietary Cd intake. However, compared with nonoccupational exposure, high occupational Cd exposure may be associated with the increased risk of prostate cancer.This meta-analysis suggests high Cd exposure as a risk factor for prostate cancer in occupational rather than nonoccupational populations. However, these results should be carefully interpreted because of the significant heterogeneity among studies. Additional large-scale and high-quality prospective studies are needed to confirm the association between Cd exposure and risk of prostate cancer.

Defining Product Intake Fraction to Quantify and Compare Exposure to Consumer Products.

PubMed

Jolliet, Olivier; Ernstoff, Alexi S; Csiszar, Susan A; Fantke, Peter

2015-08-04

There is a growing consciousness that exposure studies need to better cover near-field exposure associated with products use. To consistently and quantitatively compare human exposure to chemicals in consumer products, we introduce the concept of product intake fraction, as the fraction of a chemical within a product that is eventually taken in by the human population. This metric enables consistent comparison of exposures during consumer product use for different product-chemical combinations, exposure duration, exposure routes and pathways and for other life cycle stages. We present example applications of the product intake fraction concept, for two chemicals in two personal care products and two chemicals encapsulated in two articles, showing how intakes of these chemicals can primarily occur during product use. We demonstrate the utility of the product intake fraction and its application modalities within life cycle assessment and risk assessment contexts. The product intake fraction helps to provide a clear interface between the life cycle inventory and impact assessment phases, to identify best suited sentinel products and to calculate overall exposure to chemicals in consumer products, or back-calculate maximum allowable concentrations of substances inside products.

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

PubMed

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.

Exposure to pesticides and diabetes: A systematic review and meta-analysis.

PubMed

Evangelou, Evangelos; Ntritsos, Georgios; Chondrogiorgi, Maria; Kavvoura, Fotini K; Hernández, Antonio F; Ntzani, Evangelia E; Tzoulaki, Ioanna

2016-05-01

Diabetes mellitus has a multifactorial pathogenesis with a strong genetic component as well as many environmental and lifestyle influences. Emerging evidence suggests that environmental contaminants, including pesticides, might play an important role in the pathogenesis of diabetes. We performed a systematic review and meta-analysis of observational studies that assessed the association between exposure to pesticides and diabetes and we examined the presence of heterogeneity and biases across available studies. A comprehensive literature search of peer-reviewed original research pertaining to pesticide exposure and diabetes, published until 30st May 2015, with no language restriction, was conducted. Eligible studies were those that investigated potential associations between pesticides and diabetes without restrictions on diabetes type. We included cohort studies, case-control studies and cross-sectional studies. We extracted information on study characteristics, type of pesticide assessed, exposure assessment, outcome definition, effect estimate and sample size. We identified 22 studies assessing the association between pesticides and diabetes. The summary OR for the association of top vs. bottom tertile of exposure to any type of pesticide and diabetes was 1.58 (95% CI: 1.32-1.90, p=1.21×10(-6)), with large heterogeneity (I(2)=66.8%). Studies evaluating Type 2 diabetes in particular (n=13 studies), showed a similar summary effect comparing top vs. bottom tertiles of exposure: 1.61 (95% CI 1.37-1.88, p=3.51×10(-9)) with no heterogeneity (I(2)=0%). Analysis by type of pesticide yielded an increased risk of diabetes for DDE, heptachlor, HCB, DDT, and trans-nonachlor or chlordane. The epidemiological evidence, supported by mechanistic studies, suggests an association between exposure to organochlorine pesticides and Type 2 diabetes. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Comparative immunogenicity of 2 antirabies vaccines in a 2-1-1 post-exposure vaccination schedule].

PubMed

Landry, P; Lazzaro, M; Darioli, R

1998-09-09

Few trials have compared the Purified Duck Embryo Vaccine (PDEV) and the Human Diploid Cell Vaccine (HDCV) in a post-exposure immunization schedule of 4 shots (2 on day 0 and 1 each on day 7 and 21, or 2-1-1 schedule). A retrospective analysis compared 10 patients with PEDV and 20 with HDCV, who had received the 2-1-1 schedule as well as 20 UI mg/kg of immune globulins on day 0. The median neutralizing antibody titers on day 21 (after 3 doses) and the median of maximum titers until day 90 were higher for HDCV than for PEDV (0.6 IU/ml versus 3.5 IU/ml [p < 0.04] and 2.5 IU/ml versus 5.8 IU/ml [p < 0.03] respectively). Seven patients had not reached the seroconversion titer of 0.5 IU/ml after 3 doses (day 21). These results differ from previous studies showing a 100% seroconversion rate on day 21, and suggest that more studies are required before these 2 vaccines can be used in the 2-1-1 schedule after severe exposure.

Evaluation of exposure parameters in plain radiography: a comparative study with European guidelines.

PubMed

Lança, L; Silva, A; Alves, E; Serranheira, F; Correia, M

2008-01-01

Typical distribution of exposure parameters in plain radiography is unknown in Portugal. This study aims to identify exposure parameters that are being used in plain radiography in the Lisbon area and to compare the collected data with European references [Commission of European Communities (CEC) guidelines]. The results show that in four examinations (skull, chest, lumbar spine and pelvis), there is a strong tendency of using exposure times above the European recommendation. The X-ray tube potential values (in kV) are below the recommended values from CEC guidelines. This study shows that at a local level (Lisbon region), radiographic practice does not comply with CEC guidelines concerning exposure techniques. Further national/local studies are recommended with the objective to improve exposure optimisation and technical procedures in plain radiography. This study also suggests the need to establish national/local diagnostic reference levels and to proceed to effective measurements for exposure optimisation.

Comparative Proteomic Analysis of Human Liver Tissue and Isolated Hepatocytes with a Focus on Proteins Determining Drug Exposure.

PubMed

Vildhede, Anna; Wiśniewski, Jacek R; Norén, Agneta; Karlgren, Maria; Artursson, Per

2015-08-07

Freshly isolated human hepatocytes are considered the gold standard for in vitro studies of liver functions, including drug transport, metabolism, and toxicity. For accurate predictions of the in vivo outcome, the isolated hepatocytes should reflect the phenotype of their in vivo counterpart, i.e., hepatocytes in human liver tissue. Here, we quantified and compared the membrane proteomes of freshly isolated hepatocytes and human liver tissue using a label-free shotgun proteomics approach. A total of 5144 unique proteins were identified, spanning over 6 orders of magnitude in abundance. There was a good global correlation in protein abundance. However, the expression of many plasma membrane proteins was lower in the isolated hepatocytes than in the liver tissue. This included transport proteins that determine hepatocyte exposure to many drugs and endogenous compounds. Pathway analysis of the differentially expressed proteins confirmed that hepatocytes are exposed to oxidative stress during isolation and suggested that plasma membrane proteins were degraded via the protein ubiquitination pathway. Finally, using pitavastatin as an example, we show how protein quantifications can improve in vitro predictions of in vivo liver clearance. We tentatively conclude that our data set will be a useful resource for improved hepatocyte predictions of the in vivo outcome.

Quantitative plasma biomarker analysis in HDI exposure assessment.

PubMed

Flack, Sheila L; Fent, Kenneth W; Trelles Gaines, Linda G; Thomasen, Jennifer M; Whittaker, Steve; Ball, Louise M; Nylander-French, Leena A

2010-01-01

Quantification of amines in biological samples is important for evaluating occupational exposure to diisocyanates. In this study, we describe the quantification of 1,6-hexamethylene diamine (HDA) levels in hydrolyzed plasma of 46 spray painters applying 1,6-hexamethylene diisocyanate (HDI)-containing paint in vehicle repair shops collected during repeated visits to their workplace and their relationship with dermal and inhalation exposure to HDI monomer. HDA was detected in 76% of plasma samples, as heptafluorobutyryl derivatives, and the range of HDA concentrations was < or =0.02-0.92 microg l(-1). After log-transformation of the data, the correlation between plasma HDA levels and HDI inhalation exposure measured on the same workday was low (N = 108, r = 0.22, P = 0.026) compared with the correlation between plasma HDA levels and inhalation exposure occurring approximately 20 to 60 days before blood collection (N = 29, r = 0.57, P = 0.0014). The correlation between plasma HDA levels and HDI dermal exposure measured on the same workday, although statistically significant, was low (N = 108, r = 0.22, P = 0.040) while the correlation between HDA and dermal exposure occurring approximately 20 to 60 days before blood collection was slightly improved (N = 29, r = 0.36, P = 0.053). We evaluated various workplace factors and controls (i.e. location, personal protective equipment use and paint booth type) as modifiers of plasma HDA levels. Workers using a downdraft-ventilated booth had significantly lower plasma HDA levels relative to semi-downdraft and crossdraft booth types (P = 0.0108); this trend was comparable to HDI inhalation and dermal exposure levels stratified by booth type. These findings indicate that HDA concentration in hydrolyzed plasma may be used as a biomarker of cumulative inhalation and dermal exposure to HDI and for investigating the effectiveness of exposure controls in the workplace.

HUMAN EXPOSURE ANALYSIS, AN INTERDISCIPLINARY SCIENCE

EPA Science Inventory

The relatively new and expanding field of human exposure analysis has its genesis in the environmental movement and the interest of scientists and the public in understanding the interaction between anthropogenic and biogenic chemicals and people. The universe is full of chemi...

Meta-analysis of the association between short-term exposure to ambient ozone and respiratory hospital admissions

NASA Astrophysics Data System (ADS)

Ji, Meng; Cohan, Daniel S.; Bell, Michelle L.

2011-04-01

Ozone is associated with health impacts including respiratory outcomes; however, results differ across studies. Meta-analysis is an increasingly important approach to synthesizing evidence across studies. We conducted meta-analysis of short-term ozone exposure and respiratory hospitalizations to evaluate variation across studies and explore some of the challenges in meta-analysis. We identified 136 estimates from 96 studies and investigated how estimates differed by age, ozone metric, season, lag, region, disease category, and hospitalization type. Overall results indicate associations between ozone and various kinds of respiratory hospitalizations; however, study characteristics affected risk estimates. Estimates were similar, but higher, for the elderly compared to all ages and for previous day exposure compared to same day exposure. Comparison across studies was hindered by variation in definitions of disease categories, as some (e.g., asthma) were identified through >= 3 different sets of ICD codes. Although not all analyses exhibited evidence of publication bias, adjustment for publication bias generally lowered overall estimates. Emergency hospitalizations for total respiratory disease increased by 4.47% (95% interval: 2.48, 6.50%) per 10 ppb 24 h ozone among the elderly without adjustment for publication bias and 2.97% (1.05, 4.94%) with adjustment. Comparison of multi-city study results and meta-analysis based on single-city studies further suggested publication bias.

Fixed, low radiant exposure vs. incremental radiant exposure approach for diode laser hair reduction: a randomized, split axilla, comparative single-blinded trial.

PubMed

Pavlović, M D; Adamič, M; Nenadić, D

2015-12-01

Diode lasers are the most commonly used treatment modalities for unwanted hair reduction. Only a few controlled clinical trials but not a single randomized controlled trial (RCT) compared the impact of various laser parameters, especially radiant exposure, onto efficacy, tolerability and safety of laser hair reduction. To compare the safety, tolerability and mid-term efficacy of fixed, low and incremental radiant exposures of diode lasers (800 nm) for axillary hair removal, we conducted an intrapatient, left-to-right, patient- and assessor-blinded and controlled trial. Diode laser (800 nm) treatments were evaluated in 39 study participants (skin type II-III) with unwanted axillary hairs. Randomization and allocation to split axilla treatments were carried out by a web-based randomization tool. Six treatments were performed at 4- to 6-week intervals with study subjects blinded to the type of treatment. Final assessment of hair reduction was conducted 6 months after the last treatment by means of blinded 4-point clinical scale using photographs. The primary endpoint was reduction in hair growth, and secondary endpoints were patient-rated tolerability and satisfaction with the treatment, treatment-related pain and adverse effects. Excellent reduction in axillary hairs (≥ 76%) at 6-month follow-up visit after receiving fixed, low and incremental radiant exposure diode laser treatments was obtained in 59% and 67% of study participants respectively (Z value: 1.342, P = 0.180). Patients reported lower visual analogue scale (VAS) pain score on the fixed (4.26) than on the incremental radiant exposure side (5.64) (P < 0.0003). The only side-effect was mild and transient erythema. Subjects better tolerated the fixed, low radiant exposure protocol (P = 0.03). The majority of the study participants were satisfied with both treatments. Both low and incremental radiant exposures produced similar hair reduction and high and comparable patient satisfaction. However, low radiant

Mediation analysis with time varying exposures and mediators.

PubMed

VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J

2017-06-01

In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the "mediational g-formula." When there is no mediation, the mediational g-formula reduces to Robins' regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl's mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators.

Comparative Exposure Assessment of ESBL-Producing Escherichia coli through Meat Consumption

PubMed Central

Pielaat, Annemarie; Smid, Joost H.; van Duijkeren, Engeline; Vennemann, Francy B. C.; Wijnands, Lucas M.; Chardon, Jurgen E.

2017-01-01

The presence of extended-spectrum β-lactamase (ESBL) and plasmidic AmpC (pAmpC) producing Escherichia coli (EEC) in food animals, especially broilers, has become a major public health concern. The aim of the present study was to quantify the EEC exposure of humans in The Netherlands through the consumption of meat from different food animals. Calculations were done with a simplified Quantitative Microbiological Risk Assessment (QMRA) model. The model took the effect of pre-retail processing, storage at the consumers home and preparation in the kitchen (cross-contamination and heating) on EEC numbers on/in the raw meat products into account. The contribution of beef products (78%) to the total EEC exposure of the Dutch population through the consumption of meat was much higher than for chicken (18%), pork (4.5%), veal (0.1%) and lamb (0%). After slaughter, chicken meat accounted for 97% of total EEC load on meat, but chicken meat experienced a relatively large effect of heating during food preparation. Exposure via consumption of filet americain (a minced beef product consumed raw) was predicted to be highest (61% of total EEC exposure), followed by chicken fillet (13%). It was estimated that only 18% of EEC exposure occurred via cross-contamination during preparation in the kitchen, which was the only route by which EEC survived for surface-contaminated products. Sensitivity analysis showed that model output is not sensitive for most parameters. However, EEC concentration on meat other than chicken meat was an important data gap. In conclusion, the model assessed that consumption of beef products led to a higher exposure to EEC than chicken products, although the prevalence of EEC on raw chicken meat was much higher than on beef. The (relative) risk of this exposure for public health is yet unknown given the lack of a modelling framework and of exposure studies for other potential transmission routes. PMID:28056081

Analysis of Noise Exposure Measurements Acquired Onboard the International Space Station

NASA Technical Reports Server (NTRS)

Limardo, Jose G.; Allen, Christopher S.

2011-01-01

The International Space Station (ISS) is a unique workplace environment for U.S. astronauts and Russian cosmonauts to conduct research and live for a period of six months or more. Noise has been an enduring environmental physical hazard that has been a challenge for the U.S. space program since before the Apollo era. Noise exposure in ISS poses significant risks to the crewmembers, such as; hearing loss (temporary or permanent), possible disruptions of crew sleep, interference with speech intelligibility and communication, possible interference with crew task performance, and possible reduction in alarm audibility. Acoustic measurements were made onboard ISS and compared to requirements in order to assess the acoustic environment to which the crewmembers are exposed. The purpose of this paper is to describe in detail the noise exposure monitoring program as well as an assessment of the acoustic dosimeter data collected to date. The hardware currently being used for monitoring the noise exposure onboard ISS will be discussed. Acoustic data onboard ISS has been collected since the beginning of ISS (Increment 1, November 2001). Noise exposure data analysis will include acoustic dosimetry logged data from crew-worn dosimeters during work and sleep periods and also fixed-location measurements from Increment 1 to present day. Noise exposure levels (8-, 16- and 24-hr), LEQ, will also be provided and discussed in this paper. Future directions and recommendations for the noise exposure monitoring program will be highlighted. This acoustic data is used to ensure a safe and healthy working and living environment for the crewmembers onboard the ISS.

Tsunamis: Global Exposure and Local Risk Analysis

NASA Astrophysics Data System (ADS)

Harbitz, C. B.; Løvholt, F.; Glimsdal, S.; Horspool, N.; Griffin, J.; Davies, G.; Frauenfelder, R.

2014-12-01

The 2004 Indian Ocean tsunami led to a better understanding of the likelihood of tsunami occurrence and potential tsunami inundation, and the Hyogo Framework for Action (HFA) was one direct result of this event. The United Nations International Strategy for Disaster Risk Reduction (UN-ISDR) adopted HFA in January 2005 in order to reduce disaster risk. As an instrument to compare the risk due to different natural hazards, an integrated worldwide study was implemented and published in several Global Assessment Reports (GAR) by UN-ISDR. The results of the global earthquake induced tsunami hazard and exposure analysis for a return period of 500 years are presented. Both deterministic and probabilistic methods (PTHA) are used. The resulting hazard levels for both methods are compared quantitatively for selected areas. The comparison demonstrates that the analysis is rather rough, which is expected for a study aiming at average trends on a country level across the globe. It is shown that populous Asian countries account for the largest absolute number of people living in tsunami prone areas, more than 50% of the total exposed people live in Japan. Smaller nations like Macao and the Maldives are among the most exposed by population count. Exposed nuclear power plants are limited to Japan, China, India, Taiwan, and USA. On the contrary, a local tsunami vulnerability and risk analysis applies information on population, building types, infrastructure, inundation, flow depth for a certain tsunami scenario with a corresponding return period combined with empirical data on tsunami damages and mortality. Results and validation of a GIS tsunami vulnerability and risk assessment model are presented. The GIS model is adapted for optimal use of data available for each study. Finally, the importance of including landslide sources in the tsunami analysis is also discussed.

Exposure-response analysis and risk assessment for lung cancer in relationship to silica exposure: a 44-year cohort study of 34,018 workers.

PubMed

Liu, Yuewei; Steenland, Kyle; Rong, Yi; Hnizdo, Eva; Huang, Xiji; Zhang, Hai; Shi, Tingming; Sun, Yi; Wu, Tangchun; Chen, Weihong

2013-11-01

Crystalline silica has been classified as a human carcinogen by the International Agency for Research on Cancer (Lyon, France); however, few previous studies have provided quantitative data on silica exposure, silicosis, and/or smoking. We investigated a cohort in China (in 1960-2003) of 34,018 workers without exposure to carcinogenic confounders. Cumulative silica exposure was estimated by linking a job-exposure matrix to work history. Cox proportional hazards model was used to conduct exposure-response analysis and risk assessment. During a mean 34.5-year follow-up, 546 lung cancer deaths were identified. Categorical analyses by quartiles of cumulative silica exposure (using a 25-year lag) yielded hazard ratios of 1.26, 1.54, 1.68, and 1.70, respectively, compared with the unexposed group. Monotonic exposure-response trends were observed among nonsilicotics (P for trend < 0.001). Analyses using splines showed similar trends. The joint effect of silica and smoking was more than additive and close to multiplicative. For workers exposed from ages 20 to 65 years at 0.1 mg/m(3) of silica exposure, the estimated excess lifetime risk (through age 75 years) was 0.51%. These findings confirm silica as a human carcinogen and suggest that current exposure limits in many countries might be insufficient to protect workers from lung cancer. They also indicate that smoking cessation could help reduce lung cancer risk for silica-exposed individuals.

ANALYSIS OF HUMAN ACTIVITY DATA FOR USE IN MODELING ENVIRONMENTAL EXPOSURES

EPA Science Inventory

Human activity data are a critical part of exposure models being developed by the US EPA's National Exposure Research Laboratory (NERL). An analysis of human activity data within NERL's Consolidated Human Activity Database (CHAD) was performed in two areas relevant to exposure ...

Hair analysis for the biomonitoring of pesticide exposure: comparison with blood and urine in a rat model.

PubMed

Appenzeller, Brice M R; Hardy, Emilie M; Grova, Nathalie; Chata, Caroline; Faÿs, François; Briand, Olivier; Schroeder, Henri; Duca, Radu-Corneliu

2017-08-01

Urine and plasma have been used to date for the biomonitoring of exposure to pollutants and are still the preferred fluids for this purpose; however, these fluids mainly provide information on the short term and may present a high level of variability regarding pesticide concentrations, especially for nonpersistent compounds. Hair analysis may provide information about chronic exposure that is averaged over several months; therefore, this method has been proposed as an alternative to solely relying on these fluids. Although the possibility of detecting pesticides in hair has been demonstrated over the past few years, the unknown linkage between exposure and pesticides concentration in hair has limited the recognition of this matrix as a relevant tool for assessing human exposure. Based on a rat model in which there was controlled exposure to a mixture of pesticides composed of lindane, β-hexachlorocyclohexane, β-endosulfan, p,p'-DDT, p,p'-DDE, dieldrin, pentachlorophenol, diazinon, chlorpyrifos, cyhalothrin, permethrin, cypermethrin, propiconazole, fipronil, oxadiazon, diflufenican, trifluralin, carbofuran, and propoxur, the current work demonstrates the association between exposure intensity and resulting pesticide concentration in hair. We also compared the results obtained from a hair analysis to urine and plasma collected from the same rats. Hair, blood, and urine were collected from rats submitted to 90-day exposure by gavage to the aforementioned mixture of common pesticides at different levels. We observed a linear relationship between exposure intensity and the concentration of pesticides in the rats' hair (R Pearson 0.453-0.978, p < 0.01). A comparison with results from urine and plasma samples demonstrated the relevance of hair analysis and, for many chemicals, its superiority over using fluids for differentiating animals from different groups and for re-attributing animals to their correct groups of exposure based on pesticide concentrations in the

ALVEOLAR BREATH SAMPLING AND ANALYSIS IN HUMAN EXPOSURE ASSESSMENT STUDIES

EPA Science Inventory

Alveolar breath sampling and analysis can be extremely useful in exposure assessment studies involving volatile organic compounds (VOCs). Over recent years scientists from the EPA's National Exposure Research Laboratory have developed and refined an alveolar breath collection ...

EXPOSURE ANALYSIS MODELING SYSTEM (EXAMS): USER MANUAL AND SYSTEM DOCUMENTATION

EPA Science Inventory

The Exposure Analysis Modeling System, first published in 1982 (EPA-600/3-82-023), provides interactive computer software for formulating aquatic ecosystem models and rapidly evaluating the fate, transport, and exposure concentrations of synthetic organic chemicals - pesticides, ...

MANAGEMENT AND DISSEMINATION OF HUMAN EXPOSURE DATABASES AND OTHER DATABASES NEEDED FOR HUMAN EXPOSURE MODELING AND ANALYSIS

EPA Science Inventory

Researchers in the National Exposure Research Laboratory (NERL) have performed a number of large human exposure measurement studies during the past decade. It is the goal of the NERL to make the data available to other researchers for analysis in order to further the scientific ...

Exposure to Upper Arm Elevation During Work Compared to Leisure Among 12 Different Occupations Measured with Triaxial Accelerometers.

PubMed

Palm, Peter; Gupta, Nidhi; Forsman, Mikael; Skotte, Jørgen; Nordquist, Tobias; Holtermann, Andreas

2018-06-26

Regarding prevention of neck and shoulder pain (NSP), unsupported arm elevation is one factor that should be taken into account when performing work risk assessment. Triaxial accelerometers can be used to measure arm elevation over several days but it is not possible to differentiate between supported and unsupported arm elevation from accelerometers only. Supported arm elevation is more likely to exist during sitting than standing. The aim of the study was to evaluate the use of whole workday measurements of arm elevation with accelerometers to assess potentially harmful work exposure of arm elevation, by comparing arm elevation at work with arm elevation during leisure, in a population with diverse work tasks, and to assess how the exposure parameters were modified when upper arm elevation during sitting time was excluded. The participants, 197 workers belonging to 12 occupational groups with diverse work tasks, wore triaxial accelerometers on the dominant arm, hip, and back for 1-4 days to measure arm elevation and periods of sitting. None of the groups were found to have higher exposure to arm elevation during work compared to leisure. Even though some occupations where known to have work tasks that forced them to work with elevated arms to a large extent. A high proportion of arm elevation derived from sitting time, especially so during leisure. When arm elevation during sitting time was excluded from the analysis, arm elevation was significantly higher at work than during leisure among construction workers, garbage collectors, manufacturing workers, and domestic cleaners. Together this illustrates that it is not suitable to use whole workday measurments of arm elevation with accelerometer as a sole information source when assessing the risk for NSP due to arm elevation. Information on body posture can provide relevant contextual information in exposure assessments when it is known that the potential harmful exposure is performed in standing or walking.

Mediation analysis with time varying exposures and mediators

PubMed Central

VanderWeele, Tyler J.; Tchetgen Tchetgen, Eric J.

2016-01-01

Summary In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the “mediational g-formula.” When there is no mediation, the mediational g-formula reduces to Robins’ regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl’s mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators. PMID:28824285

Technical Overview of Ecological Risk Assessment - Analysis Phase: Exposure Characterization

EPA Pesticide Factsheets

Exposure Characterization is the second major component of the analysis phase of a risk assessment. For a pesticide risk assessment, the exposure characterization describes the potential or actual contact of a pesticide with a plant, animal, or media.

Comparative assessment of three in vitro exposure methods for combustion toxicity.

PubMed

Lestari, Fatma; Markovic, Boban; Green, Anthony R; Chattopadhyay, Gautam; Hayes, Amanda J

2006-01-01

A comparative assessment of three approaches for the use of human cells in vitro to investigate combustion toxicity was conducted. These included one indirect and two direct (passive and dynamic) exposure methods. The indirect method used an impinger system in which culture medium was used to trap the toxicants, whilst the direct exposure involved the use of a Horizontal Harvard Navicyte Chamber at the air/liquid interface. The cytotoxic effects of thermal decomposition products were assessed using the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay (Promega) on a selection of human cells including: HepG2, A549 and skin fibroblasts. A small scale laboratory fire test using a vertical tube furnace was designed for the generation of combustion products. Polymethyl methacrylate (PMMA) was selected as a model polymer to study the cytotoxic effects of combustion products. NOAEC (no observable adverse effect concentration), IC10 (10% inhibitory concentration), IC50 (50% inhibitory concentration) and TLC (total lethal concentration) values were determined from dose response curves. Assessment using the NRU (neutral red uptake) and ATP (adenosine triphosphate) assays on human lung derived cells (A549) was also undertaken. Comparison between in vitro cytotoxicity results against published toxicity data for PMMA combustion and predicted LC50 (50% lethal concentration) values calculated from identified compounds using GCMS (gas chromatography mass spectrometry) was determined. The results suggested that the indirect exposure method did not appear to simulate closely exposure via inhalation, whilst exposure at the air/liquid interface by using the dynamic method proved to be a more representative method of human inhalation. This exposure method may be a potential system for in vitro cytotoxicity testing in combustion toxicity. Copyright 2005 John Wiley & Sons, Ltd.

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

PubMed Central

Chiba, Yasutaka

2014-01-01

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

Internal exposure from building materials exhaling (222)Rn and (220)Rn as compared to external exposure due to their natural radioactivity content.

PubMed

Ujić, Predrag; Celiković, Igor; Kandić, Aleksandar; Vukanac, Ivana; Durasević, Mirjana; Dragosavac, Dusan; Zunić, Zora S

2010-01-01

The main scope of this paper is to point out the importance of introducing radon and thoron exhalation measurements from building materials in the regulating frame. Currently (2009), such a regulation of this kind of exposure is not explicitly included in the Serbian regulating network. To this end, this work reports concentration measurements of (226)Ra, (232)Th and (40)K and radon and thoron exhalation rates from building materials used in Serbia. Following detailed analysis, it was noticed that both internal exposures to radon and/or thoron exhaling from building materials may exceed external exposures to their precursors contained therein.

RECONSTRUCTING EXPOSURE SCENARIOS USING DOSE BIOMARKERS - AN APPLICATION OF BAYESIAN UNCERTAINTY ANALYSIS

EPA Science Inventory

We use Bayesian uncertainty analysis to explore how to estimate pollutant exposures from biomarker concentrations. The growing number of national databases with exposure data makes such an analysis possible. They contain datasets of pharmacokinetic biomarkers for many polluta...

Comparative Assessment of Particulate Air Pollution Exposure from Municipal Solid Waste Incinerator Emissions

PubMed Central

Ashworth, Danielle C.; Fuller, Gary W.; Toledano, Mireille B.; Font, Anna; Elliott, Paul; Hansell, Anna L.; de Hoogh, Kees

2013-01-01

Background. Research to date on health effects associated with incineration has found limited evidence of health risks, but many previous studies have been constrained by poor exposure assessment. This paper provides a comparative assessment of atmospheric dispersion modelling and distance from source (a commonly used proxy for exposure) as exposure assessment methods for pollutants released from incinerators. Methods. Distance from source and the atmospheric dispersion model ADMS-Urban were used to characterise ambient exposures to particulates from two municipal solid waste incinerators (MSWIs) in the UK. Additionally an exploration of the sensitivity of the dispersion model simulations to input parameters was performed. Results. The model output indicated extremely low ground level concentrations of PM10, with maximum concentrations of <0.01 μg/m3. Proximity and modelled PM10 concentrations for both MSWIs at postcode level were highly correlated when using continuous measures (Spearman correlation coefficients ~ 0.7) but showed poor agreement for categorical measures (deciles or quintiles, Cohen's kappa coefficients ≤ 0.5). Conclusion. To provide the most appropriate estimate of ambient exposure from MSWIs, it is essential that incinerator characteristics, magnitude of emissions, and surrounding meteorological and topographical conditions are considered. Reducing exposure misclassification is particularly important in environmental epidemiology to aid detection of low-level risks. PMID:23935644

Analysis of Noise Exposure Measurements Made Onboard the International Space Station

NASA Technical Reports Server (NTRS)

Limardo, Jose G.; Allen, Christopher S.

2011-01-01

The International Space Station (ISS) is a unique workplace environment for U.S. astronauts and Russian cosmonauts to conduct research and live for a period of six months or more. Noise has been an enduring environmental physical hazard that has been a challenge for the U.S. space program since before the Apollo era. Noise exposure in ISS poses significant risks to the crewmembers, such as; hearing loss (temporary or permanent), possible disruptions of crew sleep, interference with speech intelligibility and communication, possible interference with crew task performance, and possible reduction in alarm audibility. Acoustic measurements are made aboard ISS and compared to requirements in order to assess the acoustic environment to which the crewmembers are exposed. The purpose of this paper is to describe in detail the noise exposure monitoring program as well as an assessment of the acoustic dosimeter data collected to date. The hardware currently being used for monitoring the noise exposure onboard ISS will be discussed. Acoustic data onboard ISS has been collected since the beginning of ISS (Increment 1, November 2000). Noise exposure data analysis will include acoustic dosimetry logged data from crew-worn during work and sleep periods and also fixed-location measurements from Increment 1 to present day. Noise exposure levels (8-, 16- and 24-hr), LEQ, will also be provided and discussed in this paper. Discussions related to hearing protection will also be included. Future directions and recommendations for the noise exposure monitoring program will be highlighted. This acoustic data is used to ensure a safe and healthy working and living environment for the crewmembers aboard the ISS.

Comparative Analysis.

DTIC Science & Technology

1987-11-01

differential qualita- tive (DQ) analysis, which solves the task, providing explanations suitable for use by design systems, automated diagnosis, intelligent...solves the task, providing explanations suitable for use by design systems, automated diagnosis, intelligent tutoring systems, and explanation based...comparative analysis as an important component; the explanation is used in many different ways. * One way method of automated design is the principlvd

Airborne asbestos exposures associated with gasket and packing replacement: a simulation study and meta-analysis.

PubMed

Madl, Amy K; Hollins, Dana M; Devlin, Kathryn D; Donovan, Ellen P; Dopart, Pamela J; Scott, Paul K; Perez, Angela L

2014-08-01

Exposures to airborne asbestos during the removal and installation of internal gaskets and packing associated with a valve overhaul were characterized and compared to published data according to different variables (e.g., product, equipment, task, tool, setting, duration). Personal breathing zone and area samples were collected during twelve events simulating gasket and packing replacement, clean-up and clothing handling. These samples were analyzed using PCM and TEM methods and PCM-equivalent (PCME) airborne asbestos concentrations were calculated. A meta-analysis was performed to compare these data with airborne asbestos concentrations measured in other studies involving gaskets and packing. Short-term mechanic and assistant airborne asbestos concentrations during valve work averaged 0.013f/cc and 0.008f/cc (PCME), respectively. Area samples averaged 0.008f/cc, 0.005f/cc, and 0.003f/cc (PCME) for center, bystander, and remote background, respectively. Assuming a tradesman conservatively performs 1-3 gasket and/or packing replacements daily, an average 8-h TWA was estimated to be 0.002-0.010f/cc (PCME). Combining these results in a meta-analysis of the published exposure data showed that the majority of airborne asbestos exposures during work with gaskets and packing fall within a consistent and low range. Significant differences in airborne concentrations were observed between power versus manual tools and removal versus installation tasks. Airborne asbestos concentrations resulting from gasket and packing work during a valve overhaul are consistent with historical exposure data on replacement of asbestos-containing gasket and packing materials involving multiple variables and, in nearly all plausible scenarios, result in average airborne asbestos concentrations below contemporaneous occupational exposure limits for asbestos. Copyright © 2014 Elsevier Inc. All rights reserved.

EXHALED BREATH ANALYSIS FOR HUMAN EXPOSURE RESEARCH

EPA Science Inventory

Exhaled breath collection and analysis has historically been used in environmental research studies to characterize exposures to volatile organic compounds. The use of this approach is based on the fact that many compounds present in blood are reflected in the breath, and that...

Time series analysis of personal exposure to ambient air pollution and mortality using an exposure simulator.

PubMed

Chang, Howard H; Fuentes, Montserrat; Frey, H Christopher

2012-09-01

This paper describes a modeling framework for estimating the acute effects of personal exposure to ambient air pollution in a time series design. First, a spatial hierarchical model is used to relate Census tract-level daily ambient concentrations and simulated exposures for a subset of the study period. The complete exposure time series is then imputed for risk estimation. Modeling exposure via a statistical model reduces the computational burden associated with simulating personal exposures considerably. This allows us to consider personal exposures at a finer spatial resolution to improve exposure assessment and for a longer study period. The proposed approach is applied to an analysis of fine particulate matter of <2.5 μm in aerodynamic diameter (PM(2.5)) and daily mortality in the New York City metropolitan area during the period 2001-2005. Personal PM(2.5) exposures were simulated from the Stochastic Human Exposure and Dose Simulation. Accounting for exposure uncertainty, the authors estimated a 2.32% (95% posterior interval: 0.68, 3.94) increase in mortality per a 10 μg/m(3) increase in personal exposure to PM(2.5) from outdoor sources on the previous day. The corresponding estimates per a 10 μg/m(3) increase in PM(2.5) ambient concentration was 1.13% (95% confidence interval: 0.27, 2.00). The risks of mortality associated with PM(2.5) were also higher during the summer months.

Meta-analysis of residential exposure to radon gas and lung cancer.

PubMed Central

Pavia, Maria; Bianco, Aida; Pileggi, Claudia; Angelillo, Italo F.

2003-01-01

OBJECTIVES: To investigate the relation between residential exposure to radon and lung cancer. METHODS: A literature search was performed using Medline and other sources. The quality of studies was assessed. Adjusted odds ratios with 95% confidence intervals (CI) for the risk of lung cancer among categories of levels of exposure to radon were extracted. For each study, a weighted log-linear regression analysis of the adjusted odds ratios was performed according to radon concentration. The random effect model was used to combine values from single studies. Separate meta-analyses were performed on results from studies grouped with similar characteristics or with quality scores above or equal to the median. FINDINGS: Seventeen case-control studies were included in the meta-analysis. Quality scoring for individual studies ranged from 0.45 to 0.77 (median, 0.64). Meta-analysis based on exposure at 150 Bq/m3 gave a pooled odds ratio estimate of 1.24 (95% CI, 1.11-1.38), which indicated a potential effect of residential exposure to radon on the risk of lung cancer. Pooled estimates of fitted odds ratios at several levels of randon exposure were all significantly different from unity--ranging from 1.07 at 50 Bq/m3 to 1.43 at 250 Bq/m3. No remarkable differences from the baseline analysis were found for odds ratios from sensitivity analyses of studies in which > 75% of eligible cases were recruited (1.12, 1.00-1.25) and studies that included only women (1.29, 1.04-1.60). CONCLUSION: Although no definitive conclusions may be drawn, our results suggest a dose-response relation between residential exposure to radon and the risk of lung cancer. They support the need to develop strategies to reduce human exposure to radon. PMID:14758433

Analysis of the individual risk of altitude decompression sickness under repeated exposures

NASA Technical Reports Server (NTRS)

Kumar, K. Vasantha; Horrigan, David J.; Waligora, James M.; Gilbert, John H.

1991-01-01

In a case-control study, researchers examined the risk of decompression sickness (DCS) in individual subjects with higher number of exposures. Of the 126 subjects, 42 showed one or more episodes of DCS. Examination of the exposure-DCS relationship by odds ratio showed a linear relationship. Stratification analysis showed that sex, tissue ratio, and the presence of Doppler microbubbles were cofounders of this risk. A higher number of exposures increased the risk of DCS in this analysis.

[Role of biometric analysis in the retrospective assessment of exposure to asbestos].

PubMed

Pairon, J C; Dumortier, P

1999-12-01

Despite intrinsic limitations due to differences in the bio-persistence of the various asbestos types, in the definition of control populations and in analytical techniques used by the laboratories, mineralogical analysis of biological samples is useful in the assessment of past exposure to asbestos. It provides additional information to occupational and environmental questionnaires, particularly when exposure to asbestos is doubtful, unknown or forgotten by a subject. Results should be interpreted taking into account clinical information. A positive result does not mean existence of asbestos-related disease. A negative result does not exclude previous significant asbestos exposure, clearly identified by an occupational questionnaire (particularly for exposure to chrysotile). Threshold values indicative of a high probability of previous asbestos exposure have been established for bronchoalveolar lavage fluid (BALF) samples and lung tissue samples. Quantification of asbestos bodies by light microscopy is easy to perform. Sensitivity and specificity of this analysis towards the total pulmonary asbestos fiber burden is good. Therefore this analysis should be performed first. Mineralogical analysis in BALF or lung tissue should be considered only when sampling is supported by diagnostic or therapeutic implications.

TRIAGE DOSE ASSESSMENT FOR PARTIAL-BODY EXPOSURE: DICENTRIC ANALYSIS

PubMed Central

Moroni, Maria; Pellmar, Terry C.

2009-01-01

Partial-body biodosimetry is likely to be required after a radiological or nuclear exposure. Clinical signs and symptoms, distribution of dicentrics in circulating blood cells, organ-specific biomarkers, physical signals in teeth and nails all can provide indications of non-homogeneous exposures. Organ specific biomarkers may provide early warning regarding physiological systems at risk after radiation injury. Use of a combination of markers and symptoms will be needed for clinical insights for therapeutic approaches. Analysis of dicentrics, a marker specific for radiation injury, is the “Gold standard” of biodosimetry and can reveal partial-body exposures. Automation of sample processing for dicentric analysis can increase throughput with customization of off-the-shelf technologies for cytogenetic sample processing and information management. Automated analysis of the metaphase spreads is currently limited but improvements are in development. Our efforts bridge the technological gaps to allow the use of dicentric chromosome assay (DCA) for risk-based stratification of mass casualties. This article summarizes current knowledge on partial-body cytogenetic dose assessment synthesizing information leading to the proposal of an approach to triage dose prediction in radiation mass casualties, based on equivalent whole-body doses under partial-body exposure conditions and assesses the validity of using this model. An initial screening using only 20 metaphase spreads per subject can confirm irradiation above 2-Gy. A subsequent increase to 50 metaphases improves dose determination to allow risk stratification for clinical triage. Metaphases evaluated for inhomogeneous distribution of dicentrics can reveal partial-body exposures. We tested the validity of this approach in an in vitro model that simulates partial-body irradiation by mixing irradiated and un-irradiated lymphocytes in various proportions. Our preliminary results support the notion that this approach will

Risks for the development of outcomes related to occupational allergies: an application of the asthma-specific job exposure matrix compared with self-reports and investigator scores on job-training-related exposure.

PubMed

Suarthana, E; Heederik, D; Ghezzo, H; Malo, J-L; Kennedy, S M; Gautrin, D

2009-04-01

Risks for development of occupational sensitisation, bronchial hyper-responsiveness, rhinoconjunctival and chest symptoms at work associated with continued exposure to high molecular weight (HMW) allergens were estimated with three exposure assessment methods. A Cox regression analysis with adjustment for atopy and smoking habit was carried out in 408 apprentices in animal health technology, pastry making, and dental hygiene technology with an 8-year follow-up after training. The risk of continued exposure after training, estimated by the asthma-specific job exposure matrix (JEM), was compared with self-reports and investigator scores on job-training-related exposure. Associations between outcomes and work duration in job(s) related to training were also evaluated. Exposure to animal-derived HMW allergens, subsequent to the apprenticeship period, as estimated by the JEM, was associated with a significantly increased risk for occupational sensitisation (hazard ratio (HR) 6.4; 95% CI 2.3 to 18.2) and rhinoconjunctival symptoms at work (HR 2.6; 95% CI 1.1 to 6.2). Exposure to low molecular weight (LMW) agents significantly increased the risk of developing bronchial hyper-responsiveness (HR 2.3; 95% CI 1.1 to 5.4). Exposure verification appeared to be important to optimise the sensitivity and the specificity, as well as HRs produced by the JEM. Self-reports and investigator scores also indicated that further exposure to HMW allergens increased the risk of developing occupational allergies. The agreement between self-reports, investigator scores, and the JEM were moderate to good. There was no significant association between respiratory outcomes and work duration in jobs related to training. The asthma-specific JEM could estimate the risk of various outcomes of occupational allergies associated with exposure to HMW and LMW allergens, but it is relatively labour intensive. Exposure verification is an important integrated step in the JEM that optimised the performance of

Combined analysis of job and task benzene air exposures among workers at four US refinery operations

PubMed Central

Shin, Jennifer (Mi); Unice, Ken M; Gaffney, Shannon H; Kreider, Marisa L; Gelatt, Richard H; Panko, Julie M

2016-01-01

Workplace air samples analyzed for benzene at four US refineries from 1976 to 2007 were pooled into a single dataset to characterize similarities and differences between job titles, tasks and refineries, and to provide a robust dataset for exposure reconstruction. Approximately 12,000 non-task (>180 min) personal samples associated with 50 job titles and 4000 task (<180 min) samples characterizing 24 tasks were evaluated. Personal air sample data from four individual refineries were pooled based on a number of factors including (1) the consistent sampling approach used by refinery industrial hygienists over time, (2) the use of similar exposure controls, (3) the comparability of benzene content of process streams and end products, (4) the ability to assign uniform job titles and task codes across all four refineries, and (5) our analysis of variance (ANOVA) of the distribution of benzene air concentrations for select jobs/tasks across all four refineries. The jobs and tasks most frequently sampled included those with highest potential contact with refinery product streams containing benzene, which reflected the targeted sampling approach utilized by the facility industrial hygienists. Task and non-task data were analyzed to identify and account for significant differences within job-area, task-job, and task-area categories. This analysis demonstrated that in general, areas with benzene containing process streams were associated with greater benzene air concentrations compared to areas with process streams containing little to no benzene. For several job titles and tasks analyzed, there was a statistically significant decrease in benzene air concentration after 1990. This study provides a job and task-focused analysis of occupational exposure to benzene during refinery operations, and it should be useful for reconstructing refinery workers’ exposures to benzene over the past 30 years. PMID:26862134

Combined analysis of job and task benzene air exposures among workers at four US refinery operations.

PubMed

Burns, Amanda; Shin, Jennifer Mi; Unice, Ken M; Gaffney, Shannon H; Kreider, Marisa L; Gelatt, Richard H; Panko, Julie M

2017-03-01

Workplace air samples analyzed for benzene at four US refineries from 1976 to 2007 were pooled into a single dataset to characterize similarities and differences between job titles, tasks and refineries, and to provide a robust dataset for exposure reconstruction. Approximately 12,000 non-task (>180 min) personal samples associated with 50 job titles and 4000 task (<180 min) samples characterizing 24 tasks were evaluated. Personal air sample data from four individual refineries were pooled based on a number of factors including (1) the consistent sampling approach used by refinery industrial hygienists over time, (2) the use of similar exposure controls, (3) the comparability of benzene content of process streams and end products, (4) the ability to assign uniform job titles and task codes across all four refineries, and (5) our analysis of variance (ANOVA) of the distribution of benzene air concentrations for select jobs/tasks across all four refineries. The jobs and tasks most frequently sampled included those with highest potential contact with refinery product streams containing benzene, which reflected the targeted sampling approach utilized by the facility industrial hygienists. Task and non-task data were analyzed to identify and account for significant differences within job-area, task-job, and task-area categories. This analysis demonstrated that in general, areas with benzene containing process streams were associated with greater benzene air concentrations compared to areas with process streams containing little to no benzene. For several job titles and tasks analyzed, there was a statistically significant decrease in benzene air concentration after 1990. This study provides a job and task-focused analysis of occupational exposure to benzene during refinery operations, and it should be useful for reconstructing refinery workers' exposures to benzene over the past 30 years.

A meta-analysis of bladder cancer and diesel exhaust exposure.

PubMed

Boffetta, P; Silverman, D T

2001-01-01

The aim of this study is to review and summarize the available epidemiologic studies of bladder cancer and occupational exposure to diesel exhaust. We retrieved relevant studies and abstracted their characteristics and results. We assessed the heterogeneity of the results to decide whether to perform a fixed-effects model meta-analysis. We identified 35 relevant studies. No overall meta-analysis was performed because of heterogeneity in results. Results of railroad workers (N = 14) suggested an increased occurrence of bladder cancer, but we did not conduct a meta-analysis. The summary relative risk (RR) among truck drivers was 1.17 (95% confidence interval [CI] = 1.06-1.29, 15 studies) and that among bus drivers was 1.33 (95% CI = 1.22-1.45, 10 studies). Ten studies considered diesel exhaust exposure based on a job exposure matrix or a similar approach; the summary RR for these studies was 1.13 (95% CI = 1.00-1.27). A positive dose-response relation was suggested by 10 of the 12 studies that provided relevant information. The summary RR for high diesel exposure was 1.44 (95% CI = 1.18-1.76). There was some evidence of publication bias, however, with a lack of small studies with null or negative results. Our review suggests that exposure to diesel exhaust may increase the occurrence of bladder cancer, but the effects of misclassification, publication bias, and confounding cannot be fully taken into account.

Modelling ecological and human exposure to POPs in Venice lagoon - Part II: Quantitative uncertainty and sensitivity analysis in coupled exposure models.

PubMed

Radomyski, Artur; Giubilato, Elisa; Ciffroy, Philippe; Critto, Andrea; Brochot, Céline; Marcomini, Antonio

2016-11-01

The study is focused on applying uncertainty and sensitivity analysis to support the application and evaluation of large exposure models where a significant number of parameters and complex exposure scenarios might be involved. The recently developed MERLIN-Expo exposure modelling tool was applied to probabilistically assess the ecological and human exposure to PCB 126 and 2,3,7,8-TCDD in the Venice lagoon (Italy). The 'Phytoplankton', 'Aquatic Invertebrate', 'Fish', 'Human intake' and PBPK models available in MERLIN-Expo library were integrated to create a specific food web to dynamically simulate bioaccumulation in various aquatic species and in the human body over individual lifetimes from 1932 until 1998. MERLIN-Expo is a high tier exposure modelling tool allowing propagation of uncertainty on the model predictions through Monte Carlo simulation. Uncertainty in model output can be further apportioned between parameters by applying built-in sensitivity analysis tools. In this study, uncertainty has been extensively addressed in the distribution functions to describe the data input and the effect on model results by applying sensitivity analysis techniques (screening Morris method, regression analysis, and variance-based method EFAST). In the exposure scenario developed for the Lagoon of Venice, the concentrations of 2,3,7,8-TCDD and PCB 126 in human blood turned out to be mainly influenced by a combination of parameters (half-lives of the chemicals, body weight variability, lipid fraction, food assimilation efficiency), physiological processes (uptake/elimination rates), environmental exposure concentrations (sediment, water, food) and eating behaviours (amount of food eaten). In conclusion, this case study demonstrated feasibility of MERLIN-Expo to be successfully employed in integrated, high tier exposure assessment. Copyright © 2016 Elsevier B.V. All rights reserved.

Probabilistic Exposure Analysis for Chemical Risk Characterization

PubMed Central

Bogen, Kenneth T.; Cullen, Alison C.; Frey, H. Christopher; Price, Paul S.

2009-01-01

This paper summarizes the state of the science of probabilistic exposure assessment (PEA) as applied to chemical risk characterization. Current probabilistic risk analysis methods applied to PEA are reviewed. PEA within the context of risk-based decision making is discussed, including probabilistic treatment of related uncertainty, interindividual heterogeneity, and other sources of variability. Key examples of recent experience gained in assessing human exposures to chemicals in the environment, and other applications to chemical risk characterization and assessment, are presented. It is concluded that, although improvements continue to be made, existing methods suffice for effective application of PEA to support quantitative analyses of the risk of chemically induced toxicity that play an increasing role in key decision-making objectives involving health protection, triage, civil justice, and criminal justice. Different types of information required to apply PEA to these different decision contexts are identified, and specific PEA methods are highlighted that are best suited to exposure assessment in these separate contexts. PMID:19223660

Efficacy of exposure versus cognitive therapy in anxiety disorders: systematic review and meta-analysis

PubMed Central

2011-01-01

Background There is growing evidence of the effectiveness of Cognitive Behavioural Therapy (CBT) for a wide range of psychological disorders. There is a continued controversy about whether challenging maladaptive thoughts rather than use of behavioural interventions alone is associated with the greatest efficacy. However little is known about the relative efficacy of various components of CBT. This review aims to compare the relative efficacy of Cognitive Therapy (CT) versus Exposure (E) for a range of anxiety disorders using the most clinically relevant outcome measures and estimating the summary relative efficacy by combining the studies in a meta-analysis. Methods Psych INFO, MEDLINE and EMBASE were searched from the first available year to May 2010. All randomised controlled studies comparing the efficacy of exposure with cognitive therapy were included. Odds ratios (OR) or standardised means' differences (Hedges' g) for the most clinically relevant primary outcomes were calculated. Outcomes of the studies were grouped according to specific disorders and were combined in meta-analyses exploring short-term and long-term outcomes. Results 20 Randomised Controlled Trials with (n = 1,308) directly comparing the efficacy of CT and E in anxiety disorders were included in the meta-analysis. No statistically significant difference in the relative efficacy of CT and E was revealed in Post Traumatic Stress Disorder (PTSD), in Obsessive Compulsive Disorder (OCD) and in Panic Disorder (PD). There was a statistically significant difference favouring CT versus E in Social Phobia both in the short-term (Z = 3.72, p = 0.0002) and the long-term (Z = 3.28, p = 0.001) outcomes. Conclusions On the basis of extant literature, there appears to be no evidence of differential efficacy between cognitive therapy and exposure in PD, PTSD and OCD and strong evidence of superior efficacy of cognitive therapy in social phobia PMID:22185596

Analysis of Intervention Strategies for Inhalation Exposure to Polycyclic Aromatic Hydrocarbons and Associated Lung Cancer Risk Based on a Monte Carlo Population Exposure Assessment Model

PubMed Central

Zhou, Bin; Zhao, Bin

2014-01-01

It is difficult to evaluate and compare interventions for reducing exposure to air pollutants, including polycyclic aromatic hydrocarbons (PAHs), a widely found air pollutant in both indoor and outdoor air. This study presents the first application of the Monte Carlo population exposure assessment model to quantify the effects of different intervention strategies on inhalation exposure to PAHs and the associated lung cancer risk. The method was applied to the population in Beijing, China, in the year 2006. Several intervention strategies were designed and studied, including atmospheric cleaning, smoking prohibition indoors, use of clean fuel for cooking, enhancing ventilation while cooking and use of indoor cleaners. Their performances were quantified by population attributable fraction (PAF) and potential impact fraction (PIF) of lung cancer risk, and the changes in indoor PAH concentrations and annual inhalation doses were also calculated and compared. The results showed that atmospheric cleaning and use of indoor cleaners were the two most effective interventions. The sensitivity analysis showed that several input parameters had major influence on the modeled PAH inhalation exposure and the rankings of different interventions. The ranking was reasonably robust for the remaining majority of parameters. The method itself can be extended to other pollutants and in different places. It enables the quantitative comparison of different intervention strategies and would benefit intervention design and relevant policy making. PMID:24416436

Analysis of intervention strategies for inhalation exposure to polycyclic aromatic hydrocarbons and associated lung cancer risk based on a Monte Carlo population exposure assessment model.

PubMed

Zhou, Bin; Zhao, Bin

2014-01-01

It is difficult to evaluate and compare interventions for reducing exposure to air pollutants, including polycyclic aromatic hydrocarbons (PAHs), a widely found air pollutant in both indoor and outdoor air. This study presents the first application of the Monte Carlo population exposure assessment model to quantify the effects of different intervention strategies on inhalation exposure to PAHs and the associated lung cancer risk. The method was applied to the population in Beijing, China, in the year 2006. Several intervention strategies were designed and studied, including atmospheric cleaning, smoking prohibition indoors, use of clean fuel for cooking, enhancing ventilation while cooking and use of indoor cleaners. Their performances were quantified by population attributable fraction (PAF) and potential impact fraction (PIF) of lung cancer risk, and the changes in indoor PAH concentrations and annual inhalation doses were also calculated and compared. The results showed that atmospheric cleaning and use of indoor cleaners were the two most effective interventions. The sensitivity analysis showed that several input parameters had major influence on the modeled PAH inhalation exposure and the rankings of different interventions. The ranking was reasonably robust for the remaining majority of parameters. The method itself can be extended to other pollutants and in different places. It enables the quantitative comparison of different intervention strategies and would benefit intervention design and relevant policy making.

Optimization of camera exposure durations for multi-exposure speckle imaging of the microcirculation

PubMed Central

Kazmi, S. M. Shams; Balial, Satyajit; Dunn, Andrew K.

2014-01-01

Improved Laser Speckle Contrast Imaging (LSCI) blood flow analyses that incorporate inverse models of the underlying laser-tissue interaction have been used to develop more quantitative implementations of speckle flowmetry such as Multi-Exposure Speckle Imaging (MESI). In this paper, we determine the optimal camera exposure durations required for obtaining flow information with comparable accuracy with the prevailing MESI implementation utilized in recent in vivo rodent studies. A looping leave-one-out (LOO) algorithm was used to identify exposure subsets which were analyzed for accuracy against flows obtained from analysis with the original full exposure set over 9 animals comprising n = 314 regional flow measurements. From the 15 original exposures, 6 exposures were found using the LOO process to provide comparable accuracy, defined as being no more than 10% deviant, with the original flow measurements. The optimal subset of exposures provides a basis set of camera durations for speckle flowmetry studies of the microcirculation and confers a two-fold faster acquisition rate and a 28% reduction in processing time without sacrificing accuracy. Additionally, the optimization process can be used to identify further reductions in the exposure subsets for tailoring imaging over less expansive flow distributions to enable even faster imaging. PMID:25071956

NORMAL MAMMARY GLAND MORPHOLOGY IN PUBERTAL FEMALE MICE FOLLOWING IN UTERO AND LACTATIONAL EXPOSURE TO GENISTEIN AT LEVELS COMPARABLE TO HUMAN DIETARY EXPOSURE. (R827402)

EPA Science Inventory

The objective of the study was to determine the effect of in utero and lactational exposure to genistein (0, 0.1, 0.5, 2.5 and 10 mg/kg/day) on mammary gland morphology in female B6D2F1 mice at levels comparable to or greater than human exposures. The effect of diethylstilbest...

Children's Lead Exposure: A Multimedia Modeling Analysis to Guide Public Health Decision-Making.

PubMed

Zartarian, Valerie; Xue, Jianping; Tornero-Velez, Rogelio; Brown, James

2017-09-12

Drinking water and other sources for lead are the subject of public health concerns around the Flint, Michigan, drinking water and East Chicago, Indiana, lead in soil crises. In 2015, the U.S. Environmental Protection Agency (EPA)'s National Drinking Water Advisory Council (NDWAC) recommended establishment of a "health-based, household action level" for lead in drinking water based on children's exposure. The primary objective was to develop a coupled exposure-dose modeling approach that can be used to determine what drinking water lead concentrations keep children's blood lead levels (BLLs) below specified values, considering exposures from water, soil, dust, food, and air. Related objectives were to evaluate the coupled model estimates using real-world blood lead data, to quantify relative contributions by the various media, and to identify key model inputs. A modeling approach using the EPA's Stochastic Human Exposure and Dose Simulation (SHEDS)-Multimedia and Integrated Exposure Uptake and Biokinetic (IEUBK) models was developed using available data. This analysis for the U.S. population of young children probabilistically simulated multimedia exposures and estimated relative contributions of media to BLLs across all population percentiles for several age groups. Modeled BLLs compared well with nationally representative BLLs (0-23% relative error). Analyses revealed relative importance of soil and dust ingestion exposure pathways and associated Pb intake rates; water ingestion was also a main pathway, especially for infants. This methodology advances scientific understanding of the relationship between lead concentrations in drinking water and BLLs in children. It can guide national health-based benchmarks for lead and related community public health decisions. https://doi.org/10.1289/EHP1605.

Toxicological analysis of limonene reaction products using an in vitro exposure system

PubMed Central

Anderson, Stacey E.; Khurshid, Shahana S.; Meade, B. Jean; Lukomska, Ewa; Wells, J.R.

2015-01-01

Epidemiological investigations suggest a link between exposure to indoor air chemicals and adverse health effects. Consumer products contain reactive chemicals which can form secondary pollutants which may contribute to these effects. The reaction of limonene and ozone is a well characterized example of this type of indoor air chemistry. The studies described here characterize an in vitro model using an epithelial cell line (A549) or differentiated epithelial tissue (MucilAir™). The model is used to investigate adverse effects following exposure to combinations of limonene and ozone. In A549 cells, exposure to both the parent compounds and reaction products resulted in alterations in inflammatory cytokine production. A one hour exposure to limonene + ozone resulted in decreased proliferation when compared to cells exposed to limonene alone. Repeated dose exposures of limonene or limonene + ozone were conducted on MucilAir™ tissue. No change in proliferation was observed but increases in cytokine production were observed for both the parent compounds and reaction products. Factors such as exposure duration, chemical concentration, and sampling time point were identified to influence result outcome. These findings suggest that exposure to reaction products may produce more severe effects compared to the parent compound. PMID:23220291

Fatty acid ethyl esters (FAEE); comparative accumulation in human and guinea pig hair as a biomarker for prenatal alcohol exposure.

PubMed

Kulaga, Vivian; Caprara, Daniela; Iqbal, Umar; Kapur, Bhushan; Klein, Julia; Reynolds, James; Brien, James; Koren, Gideon

2006-01-01

To compare the incorporation rate (ICR) of fatty acid ethyl esters (FAEE) in hair between guinea pigs and humans, and to assess the relationship between ethanol exposure and FAEE concentrations in hair. Published data from pregnant guinea pigs, including maximum blood ethanol concentration (BEC), dosage regimen, and total hair FAEE concentration, were compared with published data from alcoholic patients, where dose of ethanol consumed and total hair FAEE concentration were reported. Mean values of ethanol Vmax for pregnant guinea pigs and humans were obtained from published data (26.2 and 24 mg/dl/h, respectively). Total and individual FAEE ICRs, defined as the ratio of hair FAEE to the area under the BEC-time curve (total systemic ethanol exposure), were found to be on average an order of magnitude lower in the guinea pig than in the human. The profiles of ester incorporation also differed slightly between species, with ethyl stearate being highly incorporated in guinea pig hair and less so in human hair. The results may reflect in the human greater FAEE production, greater FAEE deposition in hair, slower FAEE catabolism, differential sebum production and composition, or a combination thereof. Also, ethyl oleate was found to correlate with total systemic ethanol exposure for both guinea pigs and humans, correlation coefficients equalling 0.67 (P < 0.05) and 0.49 (P < 0.05), respectively. No other ethyl esters, nor total FAEE, were found to correlate with systemic ethanol exposure. When extrapolating FAEE concentrations in hair from guinea pigs to humans, an order of magnitude difference should be considered, with humans incorporating more FAEE per unit of ethanol exposure. Also, the results suggest caution should be taken when interpreting values of single esters because of their differential incorporation among species. Lastly, our findings suggest ethyl oleate may be of keen interest in FAEE hair analysis, particularly across species.

Analysis of Dextromethorphan and Dextrorphan in Skeletal Remains Following Differential Microclimate Exposure: Comparison of Acute vs. Repeated Drug Exposure.

PubMed

Morrison, Lucas M; Unger, Kirk A; Watterson, James H

2017-07-01

Analysis of dextromethorphan (DXM) and its metabolite dextrorphan (DXT) in skeletal remains of rats following acute (ACU, 75 mg/kg, IP, n = 10) or three repeated (REP, 25 mg/kg, IP, n = 10, 40-min interval) doses of DXM is described. Following dosing and euthanasia, rats decomposed outdoors to skeleton in two different microclimate environments (n = 5 ACU and n = 5 REP at each site): Site A (shaded forest microenvironment) and Site B (rocky substrate exposed to direct sunlight, 600 m from Site A). Two drug-free rats at each site served as negative controls. Skeletal elements (vertebrae, ribs, pelvic girdles, femora, tibiae, skulls and scapulae) were recovered, pulverized and underwent methanolic microwave assisted extraction (MAE). Extracts were analyzed by GC-MS following clean-up by solid-phase extraction (SPE). Drug levels, expressed as mass-normalized response ratios and the ratios of DXT and DXM levels (RRDXT/RRDXM) were compared between drug exposures, microclimate sites, and across skeletal elements. DXM levels differed significantly (P < 0.05) between corresponding bone elements across exposure groups (5/7-site A; 4/7-site B), but no significant differences in DXT levels were observed between corresponding elements. RRDXT/RRDXM differed significantly (P < 0.05) between corresponding bone elements across exposure groups (6/7-site A; 5/7-site B). No significant differences were observed in levels of DXM, DXT or RRDXT/RRDXM between corresponding elements from either group between sites. When data from all bone elements was pooled, levels of DXM and RRDXT/RRDXM differed significantly between exposure groups at each site, while those of DXT did not. For both exposure groups, comparison of pooled data between sites showed no significant differences in levels of DXM, DXT or RRDXT/RRDXM. Different decomposition microclimates did not impede the discrimination of DXM exposure patterns from the analyses of DXM, DXT and RRDXT/RRDXM in bone samples. © The Author 2017

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

PubMed

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.

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

PubMed Central

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

Comparing the novel method of assessing PrEP adherence/exposure using hair samples to other pharmacologic and traditional measures.

PubMed

Baxi, Sanjiv M; Liu, Albert; Bacchetti, Peter; Mutua, Gaudensia; Sanders, Eduard J; Kibengo, Freddie M; Haberer, Jessica E; Rooney, James; Hendrix, Craig W; Anderson, Peter L; Huang, Yong; Priddy, Frances; Gandhi, Monica

2015-01-01

The efficacy of pre-exposure prophylaxis (PrEP) in HIV will diminish with poor adherence; pharmacologic measures of drug exposure have proven critical to PrEP trial interpretation. We assessed drug exposure in hair against other pharmacologic and more routinely used measures to assess pill-taking. Participants were randomized to placebo, daily PrEP, or intermittent PrEP to evaluate safety and tolerability of daily versus intermittent tenofovir/emtricitabine (TFV/FTC) in 2 phase II PrEP clinical trials conducted in Africa. Different measures of drug exposure, including self-report, medication event monitoring system (MEMS)-caps openings, and TFV/FTC levels in hair and other biomatrices were compared. At weeks 8 and 16, self-reported pill-taking, MEMS-caps openings, and TFV/FTC levels in hair, plasma, and peripheral blood mononuclear cells (PBMCs) were measured. Regression models evaluated predictors of TFV/FTC concentrations in the 3 biomatrices; correlation coefficients between pharmacologic and nonpharmacologic measures were calculated. Both trials were registered on ClinicalTrials.gov (NCT00931346/NCT00971230). Hair collection was highly feasible and acceptable (100% in week 8; 96% in week 16). In multivariate analysis, strong associations were seen between pharmacologic measures and MEMS-caps openings (all P < 0.001); self-report was only weakly associated with pharmacologic measures. TFV/FTC hair concentrations were significantly correlated with levels in plasma and PBMCs (correlation coefficients, 0.41-0.86, all P < 0.001). Measuring TFV/FTC exposure in small hair samples in African PrEP trials was feasible and acceptable. Hair levels correlated strongly with PBMC, plasma concentrations, and MEMS-caps openings. As in other PrEP trials, self-report was the weakest measure of exposure. Further study of hair TFV/FTC levels in PrEP trials and demonstration projects to assess adherence/exposure is warranted.

Comparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures

PubMed Central

Baxi, Sanjiv M.; Liu, Albert; Bacchetti, Peter; Mutua, Gaudensia; Sanders, Eduard J.; Kibengo, Freddie M.; Haberer, Jessica E.; Rooney, James; Hendrix, Craig W.; Anderson, Peter L.; Huang, Yong; Priddy, Frances

2015-01-01

Objective: The efficacy of pre-exposure prophylaxis (PrEP) in HIV will diminish with poor adherence; pharmacologic measures of drug exposure have proven critical to PrEP trial interpretation. We assessed drug exposure in hair against other pharmacologic and more routinely used measures to assess pill-taking. Design: Participants were randomized to placebo, daily PrEP, or intermittent PrEP to evaluate safety and tolerability of daily versus intermittent tenofovir/emtricitabine (TFV/FTC) in 2 phase II PrEP clinical trials conducted in Africa. Different measures of drug exposure, including self-report, medication event monitoring system (MEMS)-caps openings, and TFV/FTC levels in hair and other biomatrices were compared. Methods: At weeks 8 and 16, self-reported pill-taking, MEMS-caps openings, and TFV/FTC levels in hair, plasma, and peripheral blood mononuclear cells (PBMCs) were measured. Regression models evaluated predictors of TFV/FTC concentrations in the 3 biomatrices; correlation coefficients between pharmacologic and nonpharmacologic measures were calculated. Both trials were registered on ClinicalTrials.gov (NCT00931346/NCT00971230). Results: Hair collection was highly feasible and acceptable (100% in week 8; 96% in week 16). In multivariate analysis, strong associations were seen between pharmacologic measures and MEMS-caps openings (all P < 0.001); self-report was only weakly associated with pharmacologic measures. TFV/FTC hair concentrations were significantly correlated with levels in plasma and PBMCs (correlation coefficients, 0.41–0.86, all P < 0.001). Conclusions: Measuring TFV/FTC exposure in small hair samples in African PrEP trials was feasible and acceptable. Hair levels correlated strongly with PBMC, plasma concentrations, and MEMS-caps openings. As in other PrEP trials, self-report was the weakest measure of exposure. Further study of hair TFV/FTC levels in PrEP trials and demonstration projects to assess adherence/exposure is warranted. PMID

Proteomic analysis of the renal effects of simulated occupational jet fuel exposure.

PubMed

Witzmann, F A; Bauer, M D; Fieno, A M; Grant, R A; Keough, T W; Lacey, M P; Sun, Y; Witten, M L; Young, R S

2000-03-01

We analyzed protein expression in the cytosolic fraction prepared from whole kidneys in male Swiss-Webster mice exposed 1 h/day for five days to aerosolized JP-8 jet fuel at a concentration of 1000 mg/m3, simulating military occupational exposure. Kidney cytosol samples were solubilized and separated via large-scale, high-resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Significant changes in soluble kidney proteins resulted from jet fuel exposure. Several of the altered proteins were identified by peptide mass finger-printing and related to ultrastructural abnormalities, altered protein processing, metabolic effects, and paradoxical stress protein/detoxification system responses. These results demonstrate a significant but comparatively moderate JP-8 effect on protein expression in the kidney and provide novel molecular evidence of JP-8 nephrotoxicity. Human risk is suggested by these data but conclusive assessment awaits a noninvasive search for biomarkers in JP-8 exposed humans.

World Trade Center Disaster Exposure-Related Probable Posttraumatic Stress Disorder among Responders and Civilians: A Meta-Analysis

PubMed Central

Liu, Bian; Tarigan, Lukman H.; Bromet, Evelyn J.; Kim, Hyun

2014-01-01

The World Trade Center (WTC) disaster on September 11, 2001 was an unprecedented traumatic event with long-lasting health consequences among the affected populations in the New York metropolitan area. This meta-analysis aimed to estimate the risk of probable posttraumatic stress disorder (PTSD) associated with specific types of WTC exposures. Meta-analytical findings from 10 studies of 3,271 to 20,294 participants yielded 37 relevant associations. The pooled summary odds ratio (OR) was 2.05 (95% confidence interval (CI): 1.82, 2.32), with substantial heterogeneity linked to exposure classification, cohort type, data source, PTSD assessment instrument/criteria, and lapse time since 9/11. In general, responders (e.g. police, firefighters, rescue/recovery workers and volunteers) had a lower probable PTSD risk (OR = 1.61; 95% CI: 1.39, 1.87) compared to civilians (e.g. residents, office workers, and passersby; OR = 2.71, 95% CI: 2.35, 3.12). The differences in ORs between responders and civilians were larger for physical compared to psychosocial exposure types. We also found that injury, lost someone, and witnessed horror were the three (out of six) most pernicious exposures. These findings suggest that these three exposures should be a particular focus in psychological evaluation and treatment programs in WTC intervention and future emergency preparedness efforts. PMID:25047411

World Trade Center disaster exposure-related probable posttraumatic stress disorder among responders and civilians: a meta-analysis.

PubMed

Liu, Bian; Tarigan, Lukman H; Bromet, Evelyn J; Kim, Hyun

2014-01-01

The World Trade Center (WTC) disaster on September 11, 2001 was an unprecedented traumatic event with long-lasting health consequences among the affected populations in the New York metropolitan area. This meta-analysis aimed to estimate the risk of probable posttraumatic stress disorder (PTSD) associated with specific types of WTC exposures. Meta-analytical findings from 10 studies of 3,271 to 20,294 participants yielded 37 relevant associations. The pooled summary odds ratio (OR) was 2.05 (95% confidence interval (CI): 1.82, 2.32), with substantial heterogeneity linked to exposure classification, cohort type, data source, PTSD assessment instrument/criteria, and lapse time since 9/11. In general, responders (e.g. police, firefighters, rescue/recovery workers and volunteers) had a lower probable PTSD risk (OR = 1.61; 95% CI: 1.39, 1.87) compared to civilians (e.g. residents, office workers, and passersby; OR = 2.71, 95% CI: 2.35, 3.12). The differences in ORs between responders and civilians were larger for physical compared to psychosocial exposure types. We also found that injury, lost someone, and witnessed horror were the three (out of six) most pernicious exposures. These findings suggest that these three exposures should be a particular focus in psychological evaluation and treatment programs in WTC intervention and future emergency preparedness efforts.

Occupational exposure influences on gender differences in respiratory health.

PubMed

Dimich-Ward, Helen; Beking, Kris; DyBuncio, Anne; Chan-Yeung, Moira; Du, Weiwei; Karlen, Barbara; Camp, Pat G; Kennedy, Susan M

2012-04-01

The aim of this study was to evaluate gender differences in the respiratory health of workers exposed to organic and inorganic dusts. Meta-analysis techniques incorporating logistic regression were applied to a combined file of 12 occupational health studies. Meta-analysis of data on 1,367 women and 4,240 men showed that women had higher odds of shortness of breath whether exposed to inorganic dust or having no occupational exposure, with an overall odds ratio (OR) of 2.07 (95% confidence interval [CI] = 1.57-2.73) adjusted for smoking status, age, body mass index (BMI), ethnic status, atopy, and job duration. Inorganic dust exposure was associated with the highest odds of asthma (adjusted OR = 8.38, 95% CI = 1.72-40.89) for women compared to men, but no differences were found for unexposed workers. With organic dust exposure, men had elevated odds for occasional wheeze and worse lung function compared to women. Within the limitations of this analysis, gender differences in respiratory health, as suggested by population-based studies, were confirmed in our analysis of occupational health studies, with the general type of exposure, organic or inorganic, generally determining the extent of differences. The higher risks for women compared to men for shortness of breath were robust regardless of work exposure category, with the highest odds ratios found for asthma.

UV exposure in artificial and natural weathering: A comparative study

NASA Astrophysics Data System (ADS)

Heikkilä, A.; Kazadzis, S.; Meinander, O.; Vaskuri, A.; Kärhä, P.; Mylläri, V.; Syrjälä, S.; Koskela, T.

2017-02-01

We report on a study focusing on UV exposure conditions in three different types of chambers used for accelerated ageing of materials. The first chamber is equipped with four 300-W UVA/UVB mercury vapour lamps (Ultra-Vitalux/Osram). The second chamber uses four 40-W UVA fluorescent lamps (QUV-340/Q-Lab). The third chamber is Weather-Ometer Ci3000+ from Atlas with a 4500-W xenon arc lamp. UV irradiance prevailing in each chamber was measured using Bentham DM150 double monochromator spectroradiometer. The results were compared to measurements of solar spectral UV irradiance at Jokioinen, Finland, with a Brewer MkIII double monochromator spectrophotometer. The spectral shapes of the exposing UV radiation in the different chambers were found to notably differ from each other and from the solar UV spectrum. Both spatial inhomogeneities and temporal variability caused by various factors, like the ageing of the lamps, were detected. The effects were found to strongly depend on wavelength of the exposing UV radiation. The findings of this study underline the necessity of careful characterization of the UV exposure conditions provided by the facilities used in accelerated testing of materials.

Meta-analysis on occupational exposure to pesticides--neurobehavioral impact and dose-response relationships.

PubMed

Meyer-Baron, Monika; Knapp, Guido; Schäper, Michael; van Thriel, Christoph

2015-01-01

While the health impact of high exposures to pesticides is acknowledged, the impact of chronic exposures in the absence of acute poisonings is controversial. A systematic analysis of dose-response relationships is still missing. Its absence may provoke alternative explanations for altered performances. Consequently, opportunities for health prevention in the occupational and environmental field may be missed. Objectives were (1) quantification of the neurotoxic impact of pesticides by an analysis of functional alterations in workers measured by neuropsychological performance tests, (2) estimates of dose-response relationships on the basis of exposure duration, and (3) exploration of susceptible subgroups. The meta-analysis employed a random effects model to obtain overall effects for individual performance tests. Twenty-two studies with a total of 1758 exposed and 1260 reference individuals met the inclusion criteria. At least three independent outcomes were available for twenty-six performance variables. Significant performance effects were shown in adults and referred to both cognitive and motor performances. Effect sizes ranging from dRE=-0.14 to dRE=-0.67 showed consistent outcomes for memory and attention. Relationships between effect sizes and exposure duration were indicated for individual performance variables and the total of measured performances. Studies on adolescents had to be analyzed separately due to numerous outliers. The large variation among outcomes hampered the analysis of the susceptibility in this group, while data on female workers was too scant for the analysis. Relationships exist between the impact of pesticides on performances and exposure duration. A change in test paradigms would help to decipher the impact more specifically. The use of biomarkers appropriate for lower exposures would allow a better prevention of neurotoxic effects due to occupational and environmental exposure. Intervention studies in adolescents seem warranted to

Understanding workers' exposure: Systematic review and data-analysis of emission potential for NOAA.

PubMed

Kuijpers, E; Bekker, C; Brouwer, D; le Feber, M; Fransman, W

2017-05-01

Exposure assessment for nano-objects, and their aggregates and agglomerates (NOAA), has evolved from explorative research toward more comprehensive exposure assessment, providing data to further develop currently used conservative control banding (CB) tools for risk assessment. This study aims to provide an overview of current knowledge on emission potential of NOAA across the occupational life cycle stages by a systematic review and subsequently use the results in a data analysis. Relevant parameters that influence emission were collected from peer-reviewed literature with a focus on the four source domains (SD) in the source-receptor conceptual framework for NOAA. To make the reviewed exposure data comparable, we applied an approach to normalize for workplace circumstances and measurement location, resulting in comparable "surrogate" emission levels. Finally, descriptive statistics were performed. During the synthesis of nanoparticles (SD1), mechanical reduction and gas phase synthesis resulted in the highest emission compared to wet chemistry and chemical vapor condensation. For the handling and transfer of bulk manufactured nanomaterial powders (SD2) the emission could be differentiated for five activity classes: (1) harvesting; (2) dumping; (3); mixing; (4) cleaning of a reactor; and (5) transferring. Additionally, SD2 was subdivided by the handled amount with cleaning further subdivided by energy level. Harvesting and dumping resulted in the highest emissions. Regarding processes with liquids (SD3b), it was possible to distinguish emissions for spraying (propellant gas, (high) pressure and pump), sonication and brushing/rolling. The highest emissions observed in SD3b were for propellant gas spraying and pressure spraying. The highest emissions for the handling of nano-articles (SD4) were found to nano-sized particles (including NOAA) for grinding. This study provides a valuable overview of emission assessments performed in the workplace during the

Comparative biology approaches for charged particle exposures and cancer development processes

NASA Astrophysics Data System (ADS)

Kronenberg, Amy; Gauny, Stacey; Kwoh, Ely; Sudo, Hiroko; Wiese, Claudia; Dan, Cristian; Turker, Mitchell

Comparative biology studies can provide useful information for the extrapolation of results be-tween cells in culture and the more complex environment of the tissue. In other circumstances, they provide a method to guide the interpretation of results obtained for cells from differ-ent species. We have considered several key cancer development processes following charged particle exposures using comparative biology approaches. Our particular emphases have been mutagenesis and genomic instability. Carcinogenesis requires the accumulation of mutations and most of htese mutations occur on autosomes. Two loci provide the greatest avenue for the consideration of charged particle-induced mutation involving autosomes: the TK1 locus in human cells and the APRT locus in mouse cells. Each locus can provide information on a wide variety of mutational changes, from small intragenic mutations through multilocus dele-tions and extensive tracts of mitotic recombination. In addition, the mouse model can provide a direct measurement of chromosome loss which cannot be accomplished in the human cell system. Another feature of the mouse APRT model is the ability to examine effects for cells exposed in vitro with those obtained for cells exposed in situ. We will provide a comparison of the results obtained for the TK1 locus following 1 GeV/amu Fe ion exposures to the human lymphoid cells with those obtained for the APRT locus for mouse kidney epithelial cells (in vitro or in situ). Substantial conservation of mechanisms is found amongst these three exposure scenarios, with some differences attributable to the specific conditions of exposure. A similar approach will be applied to the consideraiton of proton-induced autosomal mutations in the three model systems. A comparison of the results obtained for Fe ions vs. protons in each case will highlight LET-specificc differences in response. Another cancer development process that is receiving considerable interest is genomic instability. We

THE INFLUENCE OF HUMAN ACTIVITY PATTERNS ON PERSONAL PM EXPOSURE: A COMPARATIVE ANALYSIS OF FILTER-BASED AND CONTINUOUS PARTICLE MEASUREMENTS

EPA Science Inventory

Particulate matter (PM) exposure data from the U.S. Environmental Protection Agency sponsored 1998 Baltimore and 1999 Fresno PM Exposure Studies were analyzed to identify important microenvironments and activities that may lead to increased particle exposure for select elderly ...

Cost-effectiveness analysis of varicella vaccine as post-exposure prophylaxis in Hong Kong.

PubMed

Chui, Ka-Sing; Wu, Hiu-Lok; You, Joyce H S

2014-01-01

The varicella vaccine is an effective post-exposure prophylaxis (PEP) for chickenpox. This study aimed to analyze the cost-effectiveness of PEP using varicella vaccine for pediatric patients from the perspective of the public healthcare provider in Hong Kong. A decision tree was designed to compare cost and clinical outcomes of PEP with varicella vaccine versus no PEP in pediatric patients (aged 1-18 y) susceptible to chickenpox with household exposure. Two tiers of outcome were simulated: (1) total direct medical cost per subject exposed, and (2) the quality-adjusted life-year (QALY) loss associated with chickenpox per subject exposed. Model inputs were retrieved from local epidemiology and the medical literature. A sensitivity analysis was performed on all parameters to test the robustness of model results. The base-case analysis showed PEP with varicella vaccine to be less costly (expected cost USD 320 vs USD 731) with lower QALY loss (0.00423 QALY vs 0.01122 QALY) when compared to no PEP. The sensitivity analysis showed that PEP with varicella vaccine was less costly if PEP effectiveness was > 6.2% or the chickenpox infection rate without PEP was > 8.6%. In 10,000 Monte Carlo simulations, PEP with vaccine was cost-effective over 99% of the time, with a mean cost saving of USD 611 per patient (95% confidence interval USD 602-620; p < 0.001) and lower mean QALY loss of 0.00809 QALY (95% confidence interval 0.00802-0.00816 QALY; p < 0.001). Using varicella vaccine as PEP appears to be a cost-saving strategy to avert QALY loss in susceptible pediatric patients exposed to chickenpox in Hong Kong.

Comparison of discriminant analysis methods: Application to occupational exposure to particulate matter

NASA Astrophysics Data System (ADS)

Ramos, M. Rosário; Carolino, E.; Viegas, Carla; Viegas, Sandra

2016-06-01

Health effects associated with occupational exposure to particulate matter have been studied by several authors. In this study were selected six industries of five different areas: Cork company 1, Cork company 2, poultry, slaughterhouse for cattle, riding arena and production of animal feed. The measurements tool was a portable device for direct reading. This tool provides information on the particle number concentration for six different diameters, namely 0.3 µm, 0.5 µm, 1 µm, 2.5 µm, 5 µm and 10 µm. The focus on these features is because they might be more closely related with adverse health effects. The aim is to identify the particles that better discriminate the industries, with the ultimate goal of classifying industries regarding potential negative effects on workers' health. Several methods of discriminant analysis were applied to data of occupational exposure to particulate matter and compared with respect to classification accuracy. The selected methods were linear discriminant analyses (LDA); linear quadratic discriminant analysis (QDA), robust linear discriminant analysis with selected estimators (MLE (Maximum Likelihood Estimators), MVE (Minimum Volume Elipsoid), "t", MCD (Minimum Covariance Determinant), MCD-A, MCD-B), multinomial logistic regression and artificial neural networks (ANN). The predictive accuracy of the methods was accessed through a simulation study. ANN yielded the highest rate of classification accuracy in the data set under study. Results indicate that the particle number concentration of diameter size 0.5 µm is the parameter that better discriminates industries.

Selenium Exposure and Cancer Risk: an Updated Meta-analysis and Meta-regression

PubMed Central

Cai, Xianlei; Wang, Chen; Yu, Wanqi; Fan, Wenjie; Wang, Shan; Shen, Ning; Wu, Pengcheng; Li, Xiuyang; Wang, Fudi

2016-01-01

The objective of this study was to investigate the associations between selenium exposure and cancer risk. We identified 69 studies and applied meta-analysis, meta-regression and dose-response analysis to obtain available evidence. The results indicated that high selenium exposure had a protective effect on cancer risk (pooled OR = 0.78; 95%CI: 0.73–0.83). The results of linear and nonlinear dose-response analysis indicated that high serum/plasma selenium and toenail selenium had the efficacy on cancer prevention. However, we did not find a protective efficacy of selenium supplement. High selenium exposure may have different effects on specific types of cancer. It decreased the risk of breast cancer, lung cancer, esophageal cancer, gastric cancer, and prostate cancer, but it was not associated with colorectal cancer, bladder cancer, and skin cancer. PMID:26786590

A modular Human Exposure Model (HEM) framework to characterize near-field chemical exposure in LCIA and CAA

EPA Science Inventory

Life Cycle Impact Analysis (LCIA) has proven to be a valuable tool for systematically comparing processes and products, and has been proposed for use in Chemical Alternatives Analysis (CAA). The exposure assessment portion of the human health impact scores of LCIA has historicall...

Long duration exposure facility post-flight thermal analysis, part 1

NASA Technical Reports Server (NTRS)

Berrios, William M.; Sampair, Thomas R.

1992-01-01

Results of the post-flight thermal analysis of the Long Duration Exposure Facility (LDEF) mission are presented. The LDEF mission thermal analysis was verified by comparing the thermal model results to flight data from the LDEF Thermal Measurements System (THERM). Post-flight calculated temperature uncertainties have been reduced to under +/- 18 F from the pre-flight uncertainties of +/- 40 F. The THERM consisted of eight temperature sensors, a shared tape recorder, a standard LDEF flight battery, and an electronics control box. The temperatures were measured at selected locations on the LDEF structure interior during the first 390 days of flight and recorded for post-flight analysis. After the LDEF retrieval from Space on 12 Jan. 1990, the tape recorder was recovered from the spacecraft and the data reduced for comparison to the LDEF predicted temperatures. The LDEF mission temperatures were calculated prior to the LDEF deployment on 7 Apr. 1980, and updated after the LDEF retrieval with the following actual flight parameter data: including thermal fluxes, spacecraft attitudes, thermal coatings degradation, and contamination effects. All updated data used for the calculation of post-flight temperatures is also presented in this document.

Pain Exposure Physical Therapy versus conventional treatment in complex regional pain syndrome type 1-a cost-effectiveness analysis alongside a randomized controlled trial.

PubMed

Barnhoorn, Karlijn; Staal, J Bart; van Dongen, Robert Tm; Frölke, Jan Paul M; Klomp, Frank P; van de Meent, Henk; Adang, Eddy; Nijhuis-van der Sanden, Maria Wg

2018-06-01

To analyze cost-effectiveness of Pain Exposure Physical Therapy compared to conventional treatment alongside a randomized controlled trial (NCT00817128) in patients with complex regional pain syndrome type 1, where no clinical difference was shown between the two groups in an intention-to-treat analysis. Randomized controlled trial with 9 months follow-up. Patients were recruited from hospitals and general practitioners in the region around a university hospital. A total of 56 patients, 45 (80.4%) female, were randomized. About 4 patients in the intervention and 11 patients in the conventional group switched groups. The mean (SD) age was 44.3 (16.6) years, and in 37 (66.1%) patients, the upper extremity was affected. Patients received either Pain Exposure Physical Therapy (maximum of five sessions), or conventional treatment conforming with the Dutch multidisciplinary guideline. For the economic evaluation difference between the groups in health-related quality of life (quality-adjusted life years (QALYs)), and the clinical outcomes Impairment level Sum Score-Restricted Version and Pain Disability was determined based on the intention-to-treat analysis as well as differences in both healthcare-related costs and travel expenses. Cost-effectiveness planes were constructed using bootstrapping to compare effects and costs. No significant effects were found for QALYs (mean difference = -0.02; 95% confidence interval (CI) -0.10 to 0.04) and clinical outcomes. A cost minimization analysis showed a significant difference in costs between groups. The conventional treatment was 64% more expensive than the Pain Exposure Physical Therapy. This economic analysis shows that Pain Exposure Physical Therapy compared to conventional treatment is cost-effective.

Silicone wristbands compared with traditional polycyclic aromatic hydrocarbon exposure assessment methods

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

Dixon, Holly M.; Scott, Richard P.; Holmes, Darrell

Currently there is a lack of inexpensive, easy-to-use technology to evaluate human exposure to environmental chemicals, including polycyclic aromatic hydrocarbons (PAHs). This is the first study in which silicone wristbands were deployed alongside other PAH exposure assessment methodologies. Wristbands were used within an established Columbia Center for Children’s Environmental Health birth cohort and compared to two traditional personal PAH exposure assessment methods: biological sampling with urine and active air monitoring with samplers (i.e. polyurethane foam (PUF) and filter) housed in backpacks. All samplers were deployed simultaneously on 22 pregnant women for 48-hours. Each woman provided one spot urine sample atmore » the end of the 48-hour period. Sixty-two and 20 PAHs were quantified in the wristbands and PUF/filter, respectively; and eight hydroxy-PAH (OH-PAH) metabolites were quantified in the urine. PAHs in the PUF/filter and OH-PAHs correlate significantly for two of the eight comparisons (rs=0.53 and p=0.01; rs=0.44 and p=0.04). PAHs in the wristband and OH-PAHs correlate significantly for four of the eight comparisons; 1-OH-phenanthrene and 1-OH-pyrene strongly correlate with the parent PAHs in the wristband (rs=0.76 and p=<0.0001; rs=0.66 and p=0.0009). These results suggest wristbands are more closely associated with OH-PAHs in urine than active personal air monitoring methods.« less

Bayesian Analysis of Silica Exposure and Lung Cancer Using Human and Animal Studies.

PubMed

Bartell, Scott M; Hamra, Ghassan Badri; Steenland, Kyle

2017-03-01

Bayesian methods can be used to incorporate external information into epidemiologic exposure-response analyses of silica and lung cancer. We used data from a pooled mortality analysis of silica and lung cancer (n = 65,980), using untransformed and log-transformed cumulative exposure. Animal data came from chronic silica inhalation studies using rats. We conducted Bayesian analyses with informative priors based on the animal data and different cross-species extrapolation factors. We also conducted analyses with exposure measurement error corrections in the absence of a gold standard, assuming Berkson-type error that increased with increasing exposure. The pooled animal data exposure-response coefficient was markedly higher (log exposure) or lower (untransformed exposure) than the coefficient for the pooled human data. With 10-fold uncertainty, the animal prior had little effect on results for pooled analyses and only modest effects in some individual studies. One-fold uncertainty produced markedly different results for both pooled and individual studies. Measurement error correction had little effect in pooled analyses using log exposure. Using untransformed exposure, measurement error correction caused a 5% decrease in the exposure-response coefficient for the pooled analysis and marked changes in some individual studies. The animal prior had more impact for smaller human studies and for one-fold versus three- or 10-fold uncertainty. Adjustment for Berkson error using Bayesian methods had little effect on the exposure-response coefficient when exposure was log transformed or when the sample size was large. See video abstract at, http://links.lww.com/EDE/B160.

77 FR 37717 - Electrical Cable Test Results and Analysis During Fire Exposure

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-22

... Fire Exposure AGENCY: Nuclear Regulatory Commission. ACTION: Draft NUREG; request for comment. SUMMARY...-2128, ``Electrical Cable Test Results and Analysis during Fire Exposure (ELECTRA-FIRE), A Consolidation of the Three Major Fire-Induced Circuit and Cable Failure Experiments Performed between 2001 and 2011...

Effects of exposure to malathion on blood glucose concentration: a meta-analysis.

PubMed

Ramirez-Vargas, Marco Antonio; Flores-Alfaro, Eugenia; Uriostegui-Acosta, Mayrut; Alvarez-Fitz, Patricia; Parra-Rojas, Isela; Moreno-Godinez, Ma Elena

2018-02-01

Exposure to malathion (an organophosphate pesticide widely used around the world) has been associated with alterations in blood glucose concentration in animal models. However, the results are inconsistent. The aim of this meta-analysis was to evaluate whether malathion exposure can disturb the concentrations of blood glucose in exposed rats. We performed a literature search of online databases including PubMed, EBSCO, and Google Scholar and reviewed original articles that analyzed the relation between malathion exposure and glucose levels in animal models. The selection of articles was based on inclusion and exclusion criteria. The database search identified thirty-five possible articles, but only eight fulfilled our inclusion criteria, and these studies were included in the meta-analysis. The effect of malathion on blood glucose concentration showed a non-monotonic dose-response curve. In addition, pooled analysis showed that blood glucose concentrations were 3.3-fold higher in exposed rats than in the control group (95% CI, 2-5; Z = 3.9; p < 0.0001) in a random-effect model. This result suggested that alteration of glucose homeostasis is a possible mechanism of toxicity associated with exposure to malathion.

Pesticide exposure and risk of Alzheimer’s disease: a systematic review and meta-analysis

NASA Astrophysics Data System (ADS)

Yan, Dandan; Zhang, Yunjian; Liu, Liegang; Yan, Hong

2016-09-01

Evidence suggests that lifelong cumulative exposure to pesticides may generate lasting toxic effects on the central nervous system and contribute to the development of Alzheimer’s disease (AD). A number of reports indicate a potential association between long-term/low-dose pesticide exposure and AD, but the results are inconsistent. Therefore, we conducted a meta-analysis to clarify this association. Relevant studies were identified according to inclusion criteria. Summary odds ratios (ORs) were calculated using fixed-effects models. A total of seven studies were included in our meta-analysis. A positive association was observed between pesticide exposure and AD (OR = 1.34 95% confidence interval [CI] = 1.08, 1.67; n = 7). The summary ORs with 95% CIs from the crude and adjusted effect size studies were 1.14 (95% CI = 0.94, 1.38; n = 7) and 1.37 (95% CI = 1.09, 1.71; n = 5), respectively. The sensitivity analyses of the present meta-analysis did not substantially modify the association between pesticide exposure and AD. Subgroup analyses revealed that high-quality studies tended to show significant relationships. The present meta-analysis suggested a positive association between pesticide exposure and AD, confirming the hypothesis that pesticide exposure is a risk factor for AD. Further high-quality cohort and case-control studies are required to validate a causal relationship.

REVIEW OF NATIONAL AMBIENT AIR QUALITY STANDARDS (NAAQS) FOR CARBON MONOXIDE (CO) - EXPOSURE ANALYSIS

EPA Science Inventory

As part of the review process, a CO Exposure Analysis will also be conducted to assess the extent of human exposure posed by current ambient CO concentrations and, upon meeting the current CO NAAQS. The results of this analysis will be incorporated into the Staff Paper. (This w...

Comparative Benchmark Dose Modeling as a Tool to Make the First Estimate of Safe Human Exposure Levels to Lunar Dust

NASA Technical Reports Server (NTRS)

James, John T.; Lam, Chiu-wing; Scully, Robert R.

2013-01-01

Brief exposures of Apollo Astronauts to lunar dust occasionally elicited upper respiratory irritation; however, no limits were ever set for prolonged exposure ot lunar dust. Habitats for exploration, whether mobile of fixed must be designed to limit human exposure to lunar dust to safe levels. We have used a new technique we call Comparative Benchmark Dose Modeling to estimate safe exposure limits for lunar dust collected during the Apollo 14 mission.

Analysis of the Asbestos Permissible Exposure Level Threshold Standard

DTIC Science & Technology

1991-06-01

Risks from Smoki in. . .. . . .. ... .. 44 4. Is Society Paying Too Much? . . . . . . . . 44 a. Death Rates Compared to Lung Cancer .. 44 C. Conclusions...risk of death. Table 2 compares age-standardized lung cancer death rates (per 100,000 man-years) for cigarette smoking and/or occupational exposure to...Cancer Death Rates for Cigarette Smoking and Asbestos ZZposuze Group Exposed to Smoker Mortality Asbestos Ratio * Control No No 1.00 Asbestos Worker

Influence of exposure assessment and parameterization on exposure response. Aspects of epidemiologic cohort analysis using the Libby Amphibole asbestos worker cohort.

PubMed

Bateson, Thomas F; Kopylev, Leonid

2015-01-01

Recent meta-analyses of occupational epidemiology studies identified two important exposure data quality factors in predicting summary effect measures for asbestos-associated lung cancer mortality risk: sufficiency of job history data and percent coverage of work history by measured exposures. The objective was to evaluate different exposure parameterizations suggested in the asbestos literature using the Libby, MT asbestos worker cohort and to evaluate influences of exposure measurement error caused by historically estimated exposure data on lung cancer risks. Focusing on workers hired after 1959, when job histories were well-known and occupational exposures were predominantly based on measured exposures (85% coverage), we found that cumulative exposure alone, and with allowance of exponential decay, fit lung cancer mortality data similarly. Residence-time-weighted metrics did not fit well. Compared with previous analyses based on the whole cohort of Libby workers hired after 1935, when job histories were less well-known and exposures less frequently measured (47% coverage), our analyses based on higher quality exposure data yielded an effect size as much as 3.6 times higher. Future occupational cohort studies should continue to refine retrospective exposure assessment methods, consider multiple exposure metrics, and explore new methods of maintaining statistical power while minimizing exposure measurement error.

Esophagus cancer and occupational exposure to asbestos: results from a meta-analysis of epidemiology studies.

PubMed

Li, B; Tang, S P; Wang, K Z

2016-07-01

The relationship between occupational asbestos exposure and esophagus cancer (EC) is not fully understood. We performed a meta-analysis to quantitatively assess the association. We systematically searched databases of PubMed, EMBASE, and Web of Science for studies with quantitative estimates of asbestos exposure and EC mortality. Pooled standardized mortality ratios (SMRs) and their corresponding 95% confidence intervals (CIs) were calculated. Twenty cohort studies on EC and asbestos exposure were included in this meta-analysis. Overall, occupational exposure to asbestos was associated with an excess risk of EC (SMR = 1.24, 95% CI: 1.13-1.38, P < 0.001), with little evidence of heterogeneity among studies (I(2) = 0.0%, P = 0.682). Being male, exposure to chrysotile or mixed asbestos, working at textile industry, long study follow-up (≥20 years), Asia, Europe and America cohorts with larger cohort size (>500), and high-exposure group all contribute to significantly higher SMR. Publication bias was not detected (Egger's test P-value = 0.374). This meta-analysis suggested that occupational asbestos exposure might be associated with an increased risk of EC in male. High-exposure level of asbestos could contribute to significantly higher risk of EC mortality. © 2015 International Society for Diseases of the Esophagus.

Immunotoxicity of gallium arsenide on antigen presentation: comparative study of intratracheal and intraperitoneal exposure routes.

PubMed

Hartmann, Constance B; Harrison, M Travis; McCoy, Kathleen L

2005-01-01

Gallium arsenide (GaAs) is a semiconductor utilized in electronics and computer industries. GaAs exposure of animals causes local inflammation and systemic immune suppression. Mice were administered 2 to 200 mg/kg GaAs. On day 5, intratracheal instillation increased lung weights in a dose-dependent manner and induced pulmonary inflammation exemplified by mononuclear cell infiltration and mild epithelial hyperplasia. No fibrosis, pneumocyte hyperplasia, proteinosis, or bronchial epithelial damage was observed in the lungs. Splenic cellularity and composition were unaffected. GaAs' effect on antigen presentation by macrophages was similar after intratracheal and intraperitoneal exposure, although the lowest observable adverse effect levels differed. Macrophages from the exposure site displayed an enhanced ability to activate an antigen-specific CD4(+) helper T-cell hybridoma compared with vehicle controls, whereas splenic macrophages were defective in this function. The chemical's impact on peritoneal macrophages depended on the exposure route. GaAs exposure augmented thiol cathepsins B and L activities in macrophages from the exposure site, but decreased proteolytic activities in splenic macrophages. Alveolar macrophages had increased expression of major histocompatibility complex (MHC) Class II molecules, whereas MHC Class II expression on splenic and peritoneal macrophages was unaffected. Modified thiol cathepsin activities statistically correlated with altered efficiency of antigen presentation, whereas MHC Class II expression did not. Our study is the first one to examine the functional capability of alveolar macrophages after intratracheal GaAs instillation. Therefore, thiol cathepsins may be potential target molecules by which GaAs exposure modulates antigen presentation.

When is exposure to a natural disaster traumatic? Comparison of a trauma questionnaire and disaster exposure inventory.

PubMed

Harville, Emily W; Jacobs, Marni; Boynton-Jarrett, Renée

2015-01-01

Few studies have compared the sensitivity of trauma questionnaires to disaster inventories for assessing the prevalence of exposure to natural disaster or associated risk for post-disaster psychopathology. The objective of this analysis was to compare reporting of disaster exposure on a trauma questionnaire (Brief Trauma Questionnaire [BTQ]) to an inventory of disaster experience. Between 2011 and 2014, a sample of 841 reproductive-aged southern Louisiana women were interviewed using the BTQ and completed a detailed inventory about exposure to hurricanes and flooding. Post-traumatic stress disorder (PTSD) symptomology was measured with the Post-Traumatic Stress Checklist, and depression with the Edinburgh Depression Scale. The single question addressing disaster exposure on the BTQ had a sensitivity of between 65% and 70% relative to the more detailed questions. Reporting disaster exposure on the BTQ was more likely for those who reported illness/injury due to a hurricane or flood (74%-77%) or danger (77-79%), compared to those who reported damage (69-71%) or evacuation (64-68%). Reporting disaster exposure on the BTQ was associated with depression (odds ratio [OR] 2.29, 95% confidence interval [CI] 1.43-3.68). A single question is unlikely to be useful for assessing the degree of exposure to disaster across a broad population, and varies in utility depending on the mental health outcome of interest: the single trauma question is useful for assessing depression risk.

Daytime exposure to bright light, as compared to dim light, decreases sleepiness and improves psychomotor vigilance performance.

PubMed

Phipps-Nelson, Jo; Redman, Jennifer R; Dijk, Derk-Jan; Rajaratnam, Shantha M W

2003-09-01

This study examined the effects of bright light exposure, as compared to dim light, on daytime subjective sleepiness, incidences of slow eye movements (SEMs), and psychomotor vigilance task (PVT) performance following 2 nights of sleep restriction. The study had a mixed factorial design with 2 independent variables: light condition (bright light, 1,000 lux; dim light, < 5 lux) and time of day. The dependent variables were subjective sleepiness, PVT performance, incidences of SEMs, and salivary melatonin levels. Sleep research laboratory at Monash University. Sixteen healthy adults (10 women and 6 men) aged 18 to 35 years (mean age 25 years, 3 months). Following 2 nights of sleep restriction (5 hours each night), participants were exposed to modified constant routine conditions. Eight participants were exposed to bright light from noon until 5:00 pm. Outside the bright light exposure period (9:00 am to noon, 5:00 pm to 9:00 pm) light levels were maintained at less than 5 lux. A second group of 8 participants served as controls for the bright light exposure and were exposed to dim light throughout the entire protocol. Bright light exposure reduced subjective sleepiness, decreased SEMs, and improved PVT performance compared to dim light. Bright lights had no effect on salivary melatonin. A significant positive correlation between PVT reaction times and subjective sleepiness was observed for both groups. Changes in SEMs did not correlate significantly with either subjective sleepiness or PVT performance. Daytime bright light exposure can reduce the impact of sleep loss on sleepiness levels and performance, as compared to dim light. These effects appear to be mediated by mechanisms that are separate from melatonin suppression. The results may assist in the development of treatments for daytime sleepiness.

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

PubMed

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

2016-05-01

The medial rectus muscle (MRM) is the medial boundary to the intraconal space of the orbit, and retraction of the MRM is oftentimes necessary for endoscopic removal of intraconal tumors, e.g., orbital hemangioma. We evaluated each of the reported methods of MRM retraction for endoscopic orbital surgery and quantified the degree of intraconal exposure conferred by each method. Eight orbits from four cadaver heads were dissected. In each orbit, medial orbital decompression was performed and the MRM was retracted by using four previously described techniques: (1) external MRM retraction at the globe insertion point by using vessel loop (external group), (2) transseptal MRM retraction by using vessel loop (transseptal group), (3) transchoanal retraction of the MRM by using vessel loop (choanal group), and (4) transseptal four-handed technique by using double ball retraction by a second surgeon (transseptal double ball group). The length, height, and area of exposure of the medial intraconal space were quantified and compared. The average ± standard deviation (SD) anterior-posterior exposures for the external group, transseptal group, and transseptal double ball group were 17.51 ± 3.39 mm, 16.59 ± 4.16 mm, and 18.0 ± 15.25 mm, respectively. The choanal group provided significantly less exposure (12.39 ± 3.44 mm, p = 0.049) than the other groups. The average ± SD vertical exposures for the transseptal group, choanal group, and transseptal double ball group were 12.53 ± 4.38 mm, 13.05 ± 5.86 mm, and 13.57 ± 3.74 mm, respectively. The external group provided significantly less exposure (4.51 ± 1.56 mm, p = 0.0072) than the other groups. The transseptal and transseptal double ball groups provided the greatest total access by surface area (58.88 ± 26.96 mm(2) and 62.94 ± 34.74 mm(2), respectively) compared with the external and choanal groups (34.82 ± 23.37 mm(2) and 43.10 ± 23.68 mm(2), respectively). Although the transseptal trajectory of MRM retraction was

MR signal-fat-fraction analysis and T2* weighted imaging measure BAT reliably on humans without cold exposure.

PubMed

Holstila, Milja; Pesola, Marko; Saari, Teemu; Koskensalo, Kalle; Raiko, Juho; Borra, Ronald J H; Nuutila, Pirjo; Parkkola, Riitta; Virtanen, Kirsi A

2017-05-01

Brown adipose tissue (BAT) is compositionally distinct from white adipose tissue (WAT) in terms of triglyceride and water content. In adult humans, the most significant BAT depot is localized in the supraclavicular area. Our aim is to differentiate brown adipose tissue from white adipose tissue using fat T2* relaxation time mapping and signal-fat-fraction (SFF) analysis based on a commercially available modified 2-point-Dixon (mDixon) water-fat separation method. We hypothesize that magnetic resonance (MR) imaging can reliably measure BAT regardless of the cold-induced metabolic activation, with BAT having a significantly higher water and iron content compared to WAT. The supraclavicular area of 13 volunteers was studied on 3T PET-MRI scanner using T2* relaxation time and SFF mapping both during cold exposure and at ambient temperature; and 18 F-FDG PET during cold exposure. Volumes of interest (VOIs) were defined semiautomatically in the supraclavicular fat depot, subcutaneous WAT and muscle. The supraclavicular fat depot (assumed to contain BAT) had a significantly lower SFF and fat T2* relaxation time compared to subcutaneous WAT. Cold exposure did not significantly affect MR-based measurements. SFF and T2* values measured during cold exposure and at ambient temperature correlated inversely with the glucose uptake measured by 18 F-FDG PET. Human BAT can be reliably and safely assessed using MRI without cold activation and PET-related radiation exposure. Copyright © 2017 Elsevier Inc. All rights reserved.

Variability in quartz exposure in the construction industry: implications for assessing exposure-response relations.

PubMed

Tjoe Nij, Evelyn; Höhr, Doris; Borm, Paul; Burstyn, Igor; Spierings, Judith; Steffens, Friso; Lumens, Mieke; Spee, Ton; Heederik, Dick

2004-03-01

The aims of this study were to determine implications of inter- and intraindividual variation in exposure to respirable (quartz) dust and of heterogeneity in dust characteristics for epidemiologic research in construction workers. Full-shift personal measurements (n = 67) from 34 construction workers were collected. The between-worker and day-to-day variances of quartz and respirable dust exposure were estimated using mixed models. Heterogeneity in dust characteristics was evaluated by electron microscopic analysis and electron spin resonance. A grouping strategy based on job title resulted in a 2- and 3.5-fold reduction in expected attenuation of a hypothetical exposure-response relation for respirable dust and quartz exposure, respectively, compared to an individual based approach. Material worked on explained most of the between-worker variance in respirable dust and quartz exposure. However, for risk assessment in epidemiology, grouping workers based on the materials they work on is not practical. Microscopic characterization of dust samples showed large quantities of aluminum silicates and large quantities of smaller particles, resulting in a D(50) between 1 and 2 microm. For risk analysis, job title can be used to create exposure groups, although error is introduced by the heterogeneity of dust produced by different construction workers activities and by the nonuniformity of exposure groups. A grouping scheme based on materials worked on would be superior, for both exposure and risk assessment, but is not practical when assessing past exposure. In dust from construction sites, factors are present that are capable of influencing the toxicological potency.

A comparison of infant hair, cord blood and meconium analysis to detect fetal exposure to environmental pesticides

PubMed Central

Ostrea, Enrique M.; Bielawski, Dawn M.; Posecion, Norberto C.; Corrion, Melissa; Villanueva-Uy, Esterlita; Jin, Yan; Janisse, James J.; Ager, Joel W.

2008-01-01

OBJECTIVE The detection of fetal exposure to environmental pesticides is important because many of the pesticides are neurotoxicants and fetal exposure to these compounds can adversely affect prenatal and subsequent neurodevelopment. The aim of this study was to determine, by the comparative analysis of infant hair, cord blood and meconium, the most sensitive matrix to detect fetal exposure to pesticides. PATIENTS AND METHODS Pregnant women were prospectively recruited from an agricultural site in the Philippines where a preliminary survey indicated a substantial use at home and in the farm of the following pesticides: propoxur, cyfluthrin, chlorpyrifos, cypermethrin, pretilachlor, bioallethrin, malathion, diazinon and transfluthrin. Infant hair, cord blood and meconium were obtained after birth and were analyzed by gas chromatography/mass spectrometry for the above compounds, including lindane and DDT (1,1,1-trichloro-2,2-bis, p-chlorophenylethane) and some of their known metabolites. RESULTS A total of 638 infants were included in the study. The highest exposure rate to pesticides was detected in meconium (23.8% to propoxur, 1.9% to pretilachlor, 1.9% to cypermethrin, 0.8% to cyfluthrin, 0.6% to DDT and 0.3% to malathion and bioallethrin). Cord blood was only positive for propoxur (1.9%) whereas infant hair was only positive for chlorpyrifos (0.2%). The highest exposure was to household pesticide (propoxur). The frequency and concentration of pesticides were compared in the three matrices and there was a significantly higher frequency and concentration of propoxur, pretilachlor, DDT, cyfluthrin and cypermethrin in meconium compared to cord blood and infant hair. Pesticide metabolites were not found in any of the matrices analyzed, except in one meconium sample which was positive for DDE (4,4′ dichlorodiphenyldichloro ethylene), a DDT metabolite. CONCLUSIONS There is significant exposure of the pregnant woman and her fetus to pesticides, particularly to the home

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

PubMed

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.

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

USGS Publications Warehouse

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.

Questionable sound exposure outside of the womb: frequency analysis of environmental noise in the neonatal intensive care unit.

PubMed

Lahav, Amir

2015-01-01

Recent research raises concerns about the adverse effects of noise exposure on the developing preterm infant. However, current guidelines for NICU noise remain focused on loudness levels, leaving the problem of exposure to potentially harmful sound frequencies largely overlooked. This study examined the frequency spectra present in a level-II NICU. Noise measurements were taken in two level-II open-bay nurseries. Measurements were taken over 5 days for a period of 24 h each. Spectral analysis was focused on comparing sound frequencies in the range of human speech during daytime (7 AM-7 PM) vs. night-time (7 PM-7 AM). On average, daytime noise levels (Leq = 60.05 dBA) were higher than night-time (Leq = 58.67 dBA). Spectral analysis of frequency bands (>50 dB) revealed that infants were exposed to frequencies <500 Hz 100% of the time and to frequencies >500 Hz 57% of the time. During daytime, infants were exposed to nearly 20% more sounds within the speech frequency range compared with night-time (p = 0.018). Measuring the frequency spectra of NICU sounds is necessary to attain a thorough understanding of both the noise levels and the type of sounds that preterm infants are exposed to throughout their hospital stay. The risk of high-frequency noise exposure in the preterm population is still unclear and warrants further investigation. © 2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Comparative Transcriptomic Analysis of the Response of Dunaliella acidophila (Chlorophyta) to Short-Term Cadmium and Chronic Natural Metal-Rich Water Exposures.

PubMed

Puente-Sánchez, Fernando; Olsson, Sanna; Aguilera, Angeles

2016-10-01

Heavy metals are toxic compounds known to cause multiple and severe cellular damage. However, acidophilic extremophiles are able to cope with very high concentrations of heavy metals. This study investigated the stress response under natural environmental heavy metal concentrations in an acidophilic Dunaliella acidophila. We employed Illumina sequencing for a de novo transcriptome assembly and to identify changes in response to high cadmium concentrations and natural metal-rich water. The photosynthetic performance was also estimated by pulse amplitude-modulated (PAM) fluorescence. Transcriptomic analysis highlights a number of processes mainly related to a high constitutive expression of genes involved in oxidative stress and response to reactive oxygen species (ROS), even in the absence of heavy metals. Photosynthetic activity seems to be unaltered under short-term exposition to Cd and chronic exposure to natural metal-rich water, probably due to an increase in the synthesis of structural photosynthetic components preserving their functional integrity. An overrepresentation of Gene Ontology (GO) terms related to metabolic activities, transcription, and proteosomal catabolic process was observed when D. acidophila grew under chronic exposure to natural metal-rich water. GO terms involved in carbohydrate metabolic process, reticulum endoplasmic and Golgi bodies, were also specifically overrepresented in natural metal-rich water library suggesting an endoplasmic reticulum stress response.

Comparative Cognitive Task Analysis

DTIC Science & Technology

2007-01-01

is to perform a task analyses to determine how people operate in a specific domain on a specific task. Cognitive Task Analysis (CTA) is a set of...accomplish a task. In this chapter, we build on CTA methods by suggesting that comparative cognitive task analysis (C2TA) can help solve the aforementioned

Treatment of Phobic Disorders Using Cognitive and Exposure Methods: A Self-Efficacy Analysis.

ERIC Educational Resources Information Center

Biran, Mia; Wilson, G. Terence

1981-01-01

Examined predictions derived from self-efficacy theory in comparing the effects of exposure and cognitive interventions with simple phobics. Guided exposure (GE) was significantly superior to cognitive restructuring (CR) in enhancing approach behavior, increasing level and strength of self-efficacy, reducing subjective fear, and decreasing…

Occupational and Biomass Exposure in Chronic Obstructive Pulmonary Disease: Results of a Cross-Sectional Analysis of the On-Sint Study.

PubMed

López-Campos, José Luis; Fernández-Villar, Alberto; Calero-Acuña, Carmen; Represas-Represas, Cristina; López-Ramírez, Cecilia; Fernández, Virginia Leiro; Casamor, Ricard

2017-01-01

Although tobacco smoke is the main risk factor for chronic obstructive pulmonary disease (COPD), other inhaled toxics have also been associated with the disease. The present study analyzes data from exposure to these substances in a cohort of patients with COPD and assesses their impact on the clinical presentation of the disease. This is a cross-sectional analysis of the Clinical presentation, diagnosis and course of chronic obstructive pulmonary disease (On-Sint) study. All patients were smokers or ex-smokers as per protocol. In addition, during the inclusion visit patients were enquired about their occupational and biomass exposure history. The clinical features of patients with and without an added risk factor to tobacco were compared and those significant were entered in a multivariate logistic regression analysis, expressed as odds ratio (OR). The sample size was 1214 patients with COPD, of which 1012 (83.4%) had tobacco as the only risk factor and 202 (16.6%) had additional ones, mainly 174 (14.3%) with occupational gases and 32 (2.6%) with biomass exposure. The geographical distribution of this exposure showed a preference for the northern parts of the country and the East coast. The biomass exposure was rather low. Male gender (OR: 2.180), CAT score (OR: 1.036) and the use of long-term oxygen therapy (OR: 1.642) were associated with having an additional risk factor in the multivariate analysis. Occupational exposures are more common than biomass in Spain. COPD caused by tobacco plus other inhalants has some differential features and a more impaired quality of life. Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

Children’s Lead Exposure: A Multimedia Modeling Analysis to Guide Public Health Decision-Making

PubMed Central

Xue, Jianping; Tornero-Velez, Rogelio; Brown, James

2017-01-01

Background: Drinking water and other sources for lead are the subject of public health concerns around the Flint, Michigan, drinking water and East Chicago, Indiana, lead in soil crises. In 2015, the U.S. Environmental Protection Agency (EPA)’s National Drinking Water Advisory Council (NDWAC) recommended establishment of a “health-based, household action level” for lead in drinking water based on children’s exposure. Objectives: The primary objective was to develop a coupled exposure–dose modeling approach that can be used to determine what drinking water lead concentrations keep children’s blood lead levels (BLLs) below specified values, considering exposures from water, soil, dust, food, and air. Related objectives were to evaluate the coupled model estimates using real-world blood lead data, to quantify relative contributions by the various media, and to identify key model inputs. Methods: A modeling approach using the EPA’s Stochastic Human Exposure and Dose Simulation (SHEDS)-Multimedia and Integrated Exposure Uptake and Biokinetic (IEUBK) models was developed using available data. This analysis for the U.S. population of young children probabilistically simulated multimedia exposures and estimated relative contributions of media to BLLs across all population percentiles for several age groups. Results: Modeled BLLs compared well with nationally representative BLLs (0–23% relative error). Analyses revealed relative importance of soil and dust ingestion exposure pathways and associated Pb intake rates; water ingestion was also a main pathway, especially for infants. Conclusions: This methodology advances scientific understanding of the relationship between lead concentrations in drinking water and BLLs in children. It can guide national health-based benchmarks for lead and related community public health decisions. https://doi.org/10.1289/EHP1605 PMID:28934096

Causal mediation analysis for longitudinal data with exogenous exposure

PubMed Central

Bind, M.-A. C.; Vanderweele, T. J.; Coull, B. A.; Schwartz, J. D.

2016-01-01

Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. PMID:26272993

Comparative peptidomics analysis of neural adaptations in rats repeatedly exposed to amphetamine.

PubMed

Romanova, Elena V; Lee, Ji Eun; Kelleher, Neil L; Sweedler, Jonathan V; Gulley, Joshua M

2012-10-01

Repeated exposure to amphetamine (AMPH) induces long-lasting behavioral changes, referred to as sensitization, that are accompanied by various neuroadaptations in the brain. To investigate the chemical changes that occur during behavioral sensitization, we applied a comparative proteomics approach to screen for neuropeptide changes in a rodent model of AMPH-induced sensitization. By measuring peptide profiles with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and comparing signal intensities using principal component analysis and variance statistics, subsets of peptides are found with significant differences in the dorsal striatum, nucleus accumbens, and medial prefrontal cortex of AMPH-sensitized male Sprague-Dawley rats. These biomarker peptides, identified in follow-up analyses using liquid chromatography and tandem mass spectrometry, suggest that behavioral sensitization to AMPH is associated with complex chemical adaptations that regulate energy/metabolism, neurotransmission, apoptosis, neuroprotection, and neuritogenesis, as well as cytoskeleton integrity and neuronal morphology. Our data contribute to a growing number of reports showing that in addition to the mesolimbic dopamine system, which is the best known signaling pathway involved with reinforcing the effect of psychostimulants, concomitant chemical changes in other pathways and in neuronal organization may play a part in the overall effect of chronic AMPH exposure on behavior. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Sexual behaviour of heterosexual men and women receiving antiretroviral pre-exposure prophylaxis for HIV prevention: a longitudinal analysis.

PubMed

Mugwanya, Kenneth K; Donnell, Deborah; Celum, Connie; Thomas, Katherine K; Ndase, Patrick; Mugo, Nelly; Katabira, Elly; Ngure, Kenneth; Baeten, Jared M

2013-12-01

Scarce data are available to assess sexual behaviour of individuals using antiretroviral pre-exposure prophylaxis for HIV prevention. Increased sexual risk taking by individuals using effective HIV prevention strategies, like pre-exposure prophylaxis, could offset the benefits of HIV prevention. We studied whether the use of pre-exposure prophylaxis in HIV-uninfected men and women in HIV-serodiscordant couples was associated with increased sexual risk behaviour. We undertook a longitudinal analysis of data from the Partners PrEP Study, a double-blind, randomised, placebo-controlled trial of daily oral pre-exposure prophylaxis among HIV-uninfected partners of heterosexual HIV-serodiscordant couples (n=3163, ≥18 years of age). Efficacy for HIV prevention was publicly reported in July 2011, and participants continued monthly follow-up thereafter. We used regression analyses to compare the frequency of sex-unprotected by a condom-during the 12 months after compared with the 12 months before July 2011, to assess whether knowledge of pre-exposure prophylaxis efficacy for HIV prevention caused increased sexual risk behaviour. We analysed 56 132 person-months from 3024 HIV-uninfected individuals (64% male). The average frequency of unprotected sex with the HIV-infected study partner was 59 per 100 person-months before unmasking versus 53 after unmasking; we recorded no immediate change (p=0·66) or change over time (p=0·25) after July, 2011. We identified a significant increase in unprotected sex with outside partners after July, 2011, but the effect was small (average of 6·8 unprotected sex acts per year vs 6·2 acts in a predicted counterfactual scenario had patients remained masked, p=0·04). Compared with before July, 2011, we noted no significant increase in incident sexually transmitted infections or pregnancy after July, 2011. Pre-exposure prophylaxis, provided as part of a comprehensive prevention package, might not result in substantial changes in risk

Pediatric susceptibility to 18 industrial chemicals: a comparative analysis of newborn with young animals.

PubMed

Hasegawa, R; Hirata-Koizumi, M; Dourson, M; Parker, A; Hirose, A; Nakai, S; Kamata, E; Ema, M

2007-04-01

We comprehensively re-analyzed the toxicity data for 18 industrial chemicals from repeated oral exposures in newborn and young rats, which were previously published. Two new toxicity endpoints specific to this comparative analysis were identified, the first, the presumed no observed adverse effect level (pNOAEL) was estimated based on results of both main and dose-finding studies, and the second, the presumed unequivocally toxic level (pUETL) was defined as a clear toxic dose giving similar severity in both newborn and young rats. Based on the analyses of both pNOAEL and pUETL ratios between the different ages, newborn rats demonstrated greater susceptibility (at most 8-fold) to nearly two thirds of these 18 chemicals (mostly phenolic substances), and less or nearly equal sensitivity to the other chemicals. Exceptionally one chemical only showed toxicity in newborn rats. In addition, Benchmark Dose Lower Bound (BMDL) estimates were calculated as an alternative endpoint. Most BMDLs were comparable to their corresponding pNOAELs and the overall correlation coefficient was 0.904. We discussed how our results can be incorporated into chemical risk assessment approaches to protect pediatric health from direct oral exposure to chemicals.

Effect of membrane exposure on guided bone regeneration: A systematic review and meta-analysis.

PubMed

Garcia, Jeffrey; Dodge, Austin; Luepke, Paul; Wang, Hom-Lay; Kapila, Yvonne; Lin, Guo-Hao

2018-03-01

This review aimed at investigating the effect of membrane exposure on guided bone regeneration (GBR) outcomes at peri-implant sites and edentulous ridges. Electronic and manual literature searches were conducted by two independent reviewers using four databases, including MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials, for articles up to February 2017. Articles were included if they were human clinical trials or case series reporting outcomes of GBR procedures with and without membrane exposure. A random-effects meta-analysis was conducted, and the weighted mean difference (WMD) between the two groups and 95% confidence interval (CI) were reported. Overall, eight articles were included in the quantitative analysis. The WMD of the horizontal bone gain at edentulous ridges was -76.24% (95% CI = -137.52% to -14.97%, p = .01) between sites with membrane exposure and without exposure. In addition, the WMD of the dehiscence reduction at peri-implant sites was -27.27% (95% CI of -45.87% to -8.68%, p = .004). Both analyses showed significantly favorable outcomes at the sites without membrane exposure. Based on the findings of this study, membrane exposure after GBR procedures has a significant detrimental influence on the outcome of bone augmentation. For the edentulous ridges, the sites without membrane exposure achieved 74% more horizontal bone gain than the sites with exposure. For peri-implant dehiscence defects, the sites without membrane exposure had 27% more defect reduction than the sites with exposure. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessments of direct human exposure: the approach of EU risk assessments compared to scenario-based risk assessment.

PubMed

Wormuth, Matthias; Demou, Evangelia; Scheringer, Martin; Hungerbühler, Konrad

2007-08-01

The awareness of potential risks emerging from the use of chemicals in all parts of daily life has increased the need for risk assessments that are able to cover a high number of exposure situations and thereby ensure the safety of workers and consumers. In the European Union (EU), the practice of risk assessments for chemicals is laid down in a Technical Guidance Document; it is designed to consider environmental and human occupational and residential exposure. Almost 70 EU risk assessment reports (RARs) have been finalized for high-production-volume chemicals during the last decade. In the present study, we analyze the assessment of occupational and consumer exposure to trichloroethylene and phthalates presented in six EU RARs. Exposure scenarios in these six RARs were compared to scenarios used in applications of the scenario-based risk assessment approach to the same set of chemicals. We find that scenarios used in the selected EU RARs to represent typical exposure situations in occupational or private use of chemicals and products do not necessarily represent worst-case conditions. This can be due to the use of outdated information on technical equipment and conditions in workplaces or omission of pathways that can cause consumer exposure. Considering the need for exposure and risk assessments under the new chemicals legislation of the EU, we suggest that a transparent process of collecting data on exposure situations and of generating representative exposure scenarios is implemented to improve the accuracy of risk assessments. Also, the data sets used to assess human exposure should be harmonized, summarized in a transparent fashion, and made accessible for all risk assessors and the public.

Silicone wristbands compared with traditional polycyclic aromatic hydrocarbon exposure assessment methods.

PubMed

Dixon, Holly M; Scott, Richard P; Holmes, Darrell; Calero, Lehyla; Kincl, Laurel D; Waters, Katrina M; Camann, David E; Calafat, Antonia M; Herbstman, Julie B; Anderson, Kim A

2018-05-01

Currently there is a lack of inexpensive, easy-to-use technology to evaluate human exposure to environmental chemicals, including polycyclic aromatic hydrocarbons (PAHs). This is the first study in which silicone wristbands were deployed alongside two traditional personal PAH exposure assessment methods: active air monitoring with samplers (i.e., polyurethane foam (PUF) and filter) housed in backpacks, and biological sampling with urine. We demonstrate that wristbands worn for 48 h in a non-occupational setting recover semivolatile PAHs, and we compare levels of PAHs in wristbands to PAHs in PUFs-filters and to hydroxy-PAH (OH-PAH) biomarkers in urine. We deployed all samplers simultaneously for 48 h on 22 pregnant women in an established urban birth cohort. Each woman provided one spot urine sample at the end of the 48-h period. Wristbands recovered PAHs with similar detection frequencies to PUFs-filters. Of the 62 PAHs tested for in the 22 wristbands, 51 PAHs were detected in at least one wristband. In this cohort of pregnant women, we found more significant correlations between OH-PAHs and PAHs in wristbands than between OH-PAHs and PAHs in PUFs-filters. Only two comparisons between PAHs in PUFs-filters and OH-PAHs correlated significantly (r s  = 0.53 and p = 0.01; r s  = 0.44 and p = 0.04), whereas six comparisons between PAHs in wristbands and OH-PAHs correlated significantly (r s  = 0.44 to 0.76 and p = 0.04 to <0.0001). These results support the utility of wristbands as a biologically relevant exposure assessment tool which can be easily integrated into environmental health studies. Graphical abstract PAHs detected in samples collected from urban pregnant women.

2,4-dichlorophenoxyacetic acid (2,4-D) and risk of non-Hodgkin lymphoma: a meta-analysis accounting for exposure levels.

PubMed

Smith, Adam M; Smith, Martyn T; La Merrill, Michele A; Liaw, Jane; Steinmaus, Craig

2017-04-01

2,4-Dichlorophenoxyacetic acid (2,4-D) is one of the most commonly used selective herbicides in the world. A number of epidemiology studies have found an association between 2,4-D exposure and non-Hodgkin lymphoma (NHL) but these results are inconsistent and controversial. A previous meta-analysis found no clear association overall but did not specifically examine high-exposure groups. We conducted a systematic review and meta-analysis of the peer-reviewed epidemiologic studies of the associations between 2,4-D and NHL, with a particular focus on high-exposure groups, and evaluations of heterogeneity, dose-response, and bias. A total of 12 observational studies, 11 case-control studies, and one cohort study, were included. The summary relative risk for NHL using study results comparing subjects who were ever versus never exposed to 2,4-D was 1.38 (95% confidence interval (CI), 1.07-1.77). However, in analyses focusing on results from highly exposed groups, the summary relative risk for NHL was 1.73 (95% CI, 1.10-2.72). No clear bias based on study design, exposure assessment methodology, or outcome misclassification was seen. Overall, these findings provide new evidence for an association between NHL and exposure to the herbicide 2,4-D. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact of cytochrome P450 2C19 polymorphisms on citalopram/escitalopram exposure: a systematic review and meta-analysis.

PubMed

Chang, Ming; Tybring, Gunnel; Dahl, Marja-Liisa; Lindh, Jonatan D

2014-09-01

Citalopram and escitalopram, selective serotonin reuptake inhibitors, are primarily metabolized by cytochrome P450 (CYP) 2C19, which is a highly polymorphic enzyme known to cause inter-individual differences in pharmacokinetics. However, the impact of CYP2C19 polymorphisms on citalopram or escitalopram exposure has yet to be fully clarified, especially with regard to the quantitative impact of the CYP2C19*17 allele. The objective of this study was to quantify the effect of functional CYP2C19 allele variants on citalopram/escitalopram exposure. We performed a systematic review and meta-analysis with a structured search algorithm and eligibility criteria for including related studies, calculating the change of citalopram or escitalopram exposure associated with CYP2C19*2, *3, and *17 as compared with CYP2C19*1 using fixed-effect and random-effects models. Assessment of publication bias was performed by means of funnel plots and sensitivity analysis using meta-regressions. The pre-defined review protocol was registered at the PROSPERO international prospective register of systematic reviews, registration number CRD42013004106. Sixteen studies from 14 publications met the inclusion criteria. Eligible studies included 847 patients from psychiatric patient trials and 140 healthy subjects from pharmacokinetic studies. Compared to subjects with the EM/EM (CYP2C19*1/*1) genotype, the exposure to (es)citalopram increased by 95 % (95 % CI 40-149, p < 0.0001) in the poor metabolizer (PM)/PM (CYP2C19*2 or *3/*2 or *3), 30 % (95 % CI 4-55, p < 0.05) in the extensive metabolizer (EM)/PM (CYP2C19*1/*2 or *3), and 25 % (95 % CI 1-49, p < 0.05) in the ultrarapid metabolizer (UM)/PM (CYP2C19*17/*2 or *3) groups. In contrast, the exposure to (es)citalopram decreased by 36 % (95 % CI 27-46, p < 0.0001) in the UM/UM (CYP2C19*17/*17) and by 14 % (95 % CI 1-27, p < 0.05) in the UM/EM (CYP2C19*17/*1). This is the first meta-analysis based on a systematic review of

Historical cohort study of US man-made vitreous fiber production workers: VIII. Exposure-specific job analysis.

PubMed

Quinn, M M; Smith, T J; Youk, A O; Marsh, G M; Stone, R A; Buchanich, J M; Gula, M J

2001-09-01

All jobs held by a cohort of US man-made vitreous fiber production workers were analyzed for airborne fiber exposure. This exposure-specific job analysis was part of an exposure assessment for an epidemiologic study of mortality patterns, with particular focus on respiratory cancer, among 35,145 workers employed in 10 fiberglass and five rock or slag wool plants. The exposure assessment was conducted from the start-up date of each plant (1917 to 1946) to 1990. For the job analysis, 15,465 crude department names and 47,693 crude job titles were grouped into 1668 unique department and job pairs (UDJobs), which represented a job title linked to a specific department within each plant. Every UDJob was evaluated according to a set of job elements related to airborne fiber exposure. The distribution of the cohort person-years by UDJob and the job-exposure elements was then evaluated. The results show the main departments and jobs that employed the workers for each plant. The distribution of person-years varies across the job-exposure elements. The same job title was used in different departments within and across plants. When job titles not linked to departments were evaluated, the values of the job-exposure elements varied considerably across all plants and within plant. (1) exposure misclassification could occur if job title alone were used for the exposure assessment; (2) the job-exposure elements analysis provides an efficient way to identify major job determinants of exposure without relying on the more detailed, resource-intensive task-based approach; and (3) the evaluation of the cohort person-years by UDJobs and job-exposure elements is an effective way to identify which plants, departments, and jobs have sufficient information for making precise risk estimates in the broader epidemiologic study.

Assessing and reporting uncertainties in dietary exposure analysis: Mapping of uncertainties in a tiered approach.

PubMed

Kettler, Susanne; Kennedy, Marc; McNamara, Cronan; Oberdörfer, Regina; O'Mahony, Cian; Schnabel, Jürgen; Smith, Benjamin; Sprong, Corinne; Faludi, Roland; Tennant, David

2015-08-01

Uncertainty analysis is an important component of dietary exposure assessments in order to understand correctly the strength and limits of its results. Often, standard screening procedures are applied in a first step which results in conservative estimates. If through those screening procedures a potential exceedance of health-based guidance values is indicated, within the tiered approach more refined models are applied. However, the sources and types of uncertainties in deterministic and probabilistic models can vary or differ. A key objective of this work has been the mapping of different sources and types of uncertainties to better understand how to best use uncertainty analysis to generate more realistic comprehension of dietary exposure. In dietary exposure assessments, uncertainties can be introduced by knowledge gaps about the exposure scenario, parameter and the model itself. With this mapping, general and model-independent uncertainties have been identified and described, as well as those which can be introduced and influenced by the specific model during the tiered approach. This analysis identifies that there are general uncertainties common to point estimates (screening or deterministic methods) and probabilistic exposure assessment methods. To provide further clarity, general sources of uncertainty affecting many dietary exposure assessments should be separated from model-specific uncertainties. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

PEGylated polylysine dendrimers increase lymphatic exposure to doxorubicin when compared to PEGylated liposomal and solution formulations of doxorubicin.

PubMed

Ryan, Gemma M; Kaminskas, Lisa M; Bulitta, Jürgen B; McIntosh, Michelle P; Owen, David J; Porter, Christopher J H

2013-11-28

Improved delivery of chemotherapeutic drugs to the lymphatic system has the potential to augment outcomes for cancer therapy by enhancing activity against lymph node metastases. Uptake of small molecule chemotherapeutics into the lymphatic system, however, is limited. Nano-sized drug carriers have the potential to promote access to the lymphatics, but to this point, this has not been examined in detail. The current study therefore evaluated the lymphatic exposure of doxorubicin after subcutaneous and intravenous administration as a simple solution formulation or when formulated as a doxorubicin loaded PEGylated poly-lysine dendrimer (hydrodynamic diameter 12 nm), a PEGylated liposome (100 nm) and various pluronic micellar formulations (~5 nm) to thoracic lymph duct cannulated rats. Plasma and lymph pharmacokinetics were analysed by compartmental pharmacokinetic modelling in S-ADAPT, and Berkeley Madonna software was used to predict the lymphatic exposure of doxorubicin over an extended period of time. The micelle formulations displayed poor in vivo stability, resulting in doxorubicin profiles that were similar to that observed after administration of the doxorubicin solution formulation. In contrast, the dendrimer formulation significantly increased the recovery of doxorubicin in the thoracic lymph after both intravenous and subcutaneous dosing when compared to the solution or micellar formulation. Dendrimer-doxorubicin also resulted in increases in lymphatic doxorubicin concentrations when compared to the liposome formulation, although liposomal doxorubicin did increase lymphatic transport when compared to the solution formulation. Specifically, the dendrimer formulation increased the recovery of doxorubicin in the lymph up to 30 h post dose by up to 685 fold and 3.7 fold when compared to the solution and liposomal formulations respectively. Using the compartmental model to predict lymphatic exposure to longer time periods suggested that doxorubicin exposure to

Living network meta-analysis compared with pairwise meta-analysis in comparative effectiveness research: empirical study

PubMed Central

Nikolakopoulou, Adriani; Mavridis, Dimitris; Furukawa, Toshi A; Cipriani, Andrea; Tricco, Andrea C; Straus, Sharon E; Siontis, George C M; Egger, Matthias

2018-01-01

Abstract Objective To examine whether the continuous updating of networks of prospectively planned randomised controlled trials (RCTs) (“living” network meta-analysis) provides strong evidence against the null hypothesis in comparative effectiveness of medical interventions earlier than the updating of conventional, pairwise meta-analysis. Design Empirical study of the accumulating evidence about the comparative effectiveness of clinical interventions. Data sources Database of network meta-analyses of RCTs identified through searches of Medline, Embase, and the Cochrane Database of Systematic Reviews until 14 April 2015. Eligibility criteria for study selection Network meta-analyses published after January 2012 that compared at least five treatments and included at least 20 RCTs. Clinical experts were asked to identify in each network the treatment comparison of greatest clinical interest. Comparisons were excluded for which direct and indirect evidence disagreed, based on side, or node, splitting test (P<0.10). Outcomes and analysis Cumulative pairwise and network meta-analyses were performed for each selected comparison. Monitoring boundaries of statistical significance were constructed and the evidence against the null hypothesis was considered to be strong when the monitoring boundaries were crossed. A significance level was defined as α=5%, power of 90% (β=10%), and an anticipated treatment effect to detect equal to the final estimate from the network meta-analysis. The frequency and time to strong evidence was compared against the null hypothesis between pairwise and network meta-analyses. Results 49 comparisons of interest from 44 networks were included; most (n=39, 80%) were between active drugs, mainly from the specialties of cardiology, endocrinology, psychiatry, and rheumatology. 29 comparisons were informed by both direct and indirect evidence (59%), 13 by indirect evidence (27%), and 7 by direct evidence (14%). Both network and pairwise meta-analysis

Effects of vehicle-ride exposure on cervical pathology: a meta-analysis

PubMed Central

KOLLOCK, Roger; GAMES, Kenneth; WILSON, Alan E.; SEFTON, JoEllen M.

2015-01-01

Research to date on the effect vehicle-ride exposure has on the development of cervical pathologies in mounted Warfighters is conflicting. The purpose of this study was to determine if the literature suggests a definite effect of vehicle-ride exposure on cervical pathology. Databases were searched using multiple combinations of select terms. Twelve studies meeting the inclusion criteria were included in the meta-analysis. The results of the meta-analysis revealed that overall vehicle-ride exposure was likely to increase cervical pathology (p=0.01, odds ratio=1.59, 95% CI=1.16−2.17). Using vehicle type as a moderator it was found that vehicle-ride exposure in ground-based vehicles (p=0.01, odds ratio=2.33, 95% CI=1.41−3.85) and fixed-wing aircraft (p=0.01, odds ratio =1.59, 95% CI=1.13−2.23) were likely to increase cervical pathology. Using operator/other personnel moderator it was found that in the populations tested, fighter pilots or fighter jet weapons systems operators were more likely to develop a cervical pathology (p<0.001, odds ratio=1.78, 95% CI=1.26−2.50). The available studies indicate an increase in cervical pathology for personnel exposed to ground-based vehicles and fixed-wing aircraft. PMID:25739897

Biodiesel versus Diesel: A Pilot Study Comparing Exhaust Exposures for Employees at a Rural Municipal Facility

PubMed Central

Traviss, Nora; Thelen, Brett Amy; Ingalls, Jaime Kathryn; Treadwell, Melinda Dawn

2016-01-01

Many organizations interested in renewable, domestic energy have switched from petroleum diesel to biodiesel blends for use in transportation and heavy-duty equipment. Although considerable evidence exists on the negative health effects of petroleum diesel exhaust exposures in occupational settings, there has been little research examining biodiesel exposures. Working collaboratively with a local municipality, concentrations of particulate matter (PM) and other air toxics were measured at a recycling facility in southwestern New Hampshire while heavy equipment operated first on petroleum diesel and then on a B20 blend (20% soy-based biodiesel/80% petroleum diesel). This pilot study used a combination of established industrial hygiene and environmental air monitoring methods to estimate occupational exposure profiles to PM and air toxics from combustion of petroleum diesel and biodiesel. Results indicate that B20 use dramatically reduces work area respirable particle, PM2.5 (PM ≤2.5 µm in aerodynamic diameter), and formaldehyde levels compared with petroleum diesel. Some volatile organic compound concentrations were higher for petroleum diesel and others were higher for the B20 blend. Overall, this study suggests that biodiesel blends reduce worker exposure to and health risk from petroleum diesel exhaust, but additional exposure research is recommended. PMID:20863048

A study on quantitative analysis of exposure dose caused by patient depending on time and distance in nuclear medicine examination

NASA Astrophysics Data System (ADS)

Kim, H. S.; Cho, J. H.; Shin, S. G.; Dong, K. R.; Chung, W. K.; Chung, J. E.

2013-01-01

This study evaluated possible actions that can help protect against and reduce radiation exposure by measuring the exposure dose for each type of isotope that is used frequently in nuclear medicine before performing numerical analysis of the effective half-life based on the measurement results. From July to August in 2010, the study targeted 10, 6 and 5 people who underwent an 18F-FDG (fludeoxyglucose) positron emission tomography (PET) scan, 99mTc-HDP bone scan, and 201Tl myocardial single-photon emission computed tomography (SPECT) scan, respectively, in the nuclear medicine department. After injecting the required medicine into the subjects, a survey meter was used to measure the dose depending on the distance from the heart and time elapsed. For the 18F-FDG PET scan, the dose decreased by approximately 66% at 90 min compared to that immediately after the injection and by 78% at a distance of 1 m compared to that at 0.3 m. In the 99mTc-HDP bone scan, the dose decreased by approximately 71% in 200 min compared to that immediately after the injection and by approximately 78% at a distance of 1 m compared to that at 0.3 m. In the 201Tl myocardial SPECT scan, the dose decreased by approximately 30% in 250 min compared to that immediately after the injection and by approximately 55% at a distance of 1 m compared to that at 0.3 m. In conclusion, the dose decreases by a large margin depending on the distance and time. In conclusion, this study measured the exposure doses by isotopes, distance from the heart and exposure time, and found that the doses were reduced significantly according the distance and the time.

Causal mediation analysis for longitudinal data with exogenous exposure.

PubMed

Bind, M-A C; Vanderweele, T J; Coull, B A; Schwartz, J D

2016-01-01

Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The alignment of immediate health effects of multi-hour exposure periods

EPA Science Inventory

Objective: Exposure to [me airborne particulate matter (PM2.5) has been associated with cardiovascular outcomes, including acute effects on endothelial dysfunction. With such immediate effects, the choice ofthe exposure timeframe may be a critical factor. This analysis compares t...

Affecting Factors of Secondhand Smoke Exposure in Korea: Focused on Different Exposure Locations.

PubMed

Sun, Li Yuan; Cheong, Hae Kwan; Lee, Eun Whan; Kang, Kyeong Jin; Park, Jae Hyun

2016-09-01

Exposure to secondhand smoke (SHS) not only can cause serious illness, but is also an economic and social burden. Contextual and individual factors of non-smoker exposure to SHS depend on location. However, studies focusing on this subject are lacking. In this study, we described and compared the factors related to SHS exposure according to location in Korea. Regarding individual factors related to SHS exposure, a common individual variable model and location-specific variable model was used to evaluate SHS exposure at home/work/public locations based on sex. In common individual variables, such as age, and smoking status showed different relationships with SHS exposure in different locations. Among home-related variables, housing type and family with a single father and unmarried children showed the strongest positive relationships with SHS exposure in both males and females. In the workplace, service and sales workers, blue-collar workers, and manual laborers showed the strongest positive association with SHS exposure in males and females. For multilevel analysis in public places, only SHS exposure in females was positively related with cancer screening rate. Exposure to SHS in public places showed a positive relationship with drinking rate and single-parent family in males and females. The problem of SHS embodies social policies and interactions between individuals and social contextual factors. Policy makers should consider the contextual factors of specific locations and regional and individual context, along with differences between males and females, to develop effective strategies for reducing SHS exposure.

Wood dust exposure and lung cancer risk: a meta-analysis.

PubMed

Hancock, David G; Langley, Mary E; Chia, Kwan Leung; Woodman, Richard J; Shanahan, E Michael

2015-12-01

Occupational lung cancers represent a major health burden due to their increasing prevalence and poor long-term outcomes. While wood dust is a confirmed human carcinogen, its association with lung cancer remains unclear due to inconsistent findings in the literature. We aimed to clarify this association using meta-analysis. We performed a search of 10 databases to identify studies published until June 2014. We assessed the lung cancer risk associated with wood dust exposure as the primary outcome and with wood dust-related occupations as a secondary outcome. Random-effects models were used to pool summary risk estimates. 85 publications were included in the meta-analysis. A significantly increased risk for developing lung cancer was observed among studies that directly assessed wood dust exposure (RR 1.21, 95% CI 1.05 to 1.39, n=33) and that assessed wood dust-related occupations (RR 1.15, 95% CI 1.07 to 1.23, n=59). In contrast, a reduced risk for lung cancer was observed among wood dust (RR 0.63, 95% CI 0.39 to 0.99, n=5) and occupation (RR 0.96, 95% CI 0.95 to 0.98, n=1) studies originating in Nordic countries, where softwood dust is the primary exposure. These results were independent of the presence of adjustment for smoking and exposure classification methods. Only minor differences in risk between the histological subtypes were identified. This meta-analysis provides strong evidence for an association between wood dust and lung cancer, which is critically influenced by the geographic region of the study. The reasons for this region-specific effect estimates remain to be clarified, but may suggest a differential effect for hardwood and softwood dusts. 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/

RECENT DEVELOPMENTS IN EXHALED BREATH ANALYSIS AND HUMAN EXPOSURE RESEARCH

EPA Science Inventory

Exhaled breath collection and analysis has historically been used in environmental research studies to characterize exposures to volatile organic compounds. The use of this approach is based on the fact that many compounds present in blood are reflected in the breath, and that u...

Allograft materials in phalloplasty: a comparative analysis.

PubMed

Solomon, Mark P; Komlo, Caroline; Defrain, Molly

2013-09-01

Allograft use has increased recently with the rising use of allograft materials in breast surgery. There are few data that compare the performance of the various allograft materials in this application, despite marketing efforts by the manufacturers to present one allograft material as superior to another. Phalloplasty is a procedure that uses allografts for penis girth augmentation. Preparation of these grafts differs with each manufacturer. We report our experience with 3 different types of allografts for this procedure. This allows for the comparison of these materials in their performance with a single model. Forty-seven patients who underwent penis girth enhancement with allograft material were reviewed. All patients underwent circumferential grafting to the shaft of the penis at the level of Buck's fascia. Graft materials included AlloDerm (n = 9), Belladerm (n = 20), and Repriza (n = 21). Charts were reviewed for material type, presence and type of infection, wound exposure, and graft loss with attention to the type of allograft material that was used. Follow-up ranged from 1 to 120 months with an average of 11.25 months. Infection, defined as an open wound with graft exposure, occurred in 20 (42%) of 47 patients. Of these, graft exposure only occurred in 17 (36%) patients, whereas 3 (6%) patients sustained total graft loss. Graft exposure or loss occurred in 3 patients who had AlloDerm, 9 patients with Belladerm, and 8 patients with Repriza. No patients with AlloDerm sustained graft loss, whereas 2 patients with Belladerm and 1 patient with Repriza sustained graft loss. There were no statistical differences among these graft types with regard to infection or graft loss. Three different brands of allograft material were used in 1 surgical procedure and followed up for their performance with regard to exposure and infection. In this model, there is no difference in the rate of infection in these materials despite their different methods of preparation

Assessment of General Public Exposure to LTE signals compared to other Cellular Networks Present in Thessaloniki, Greece.

PubMed

Gkonis, Fotios; Boursianis, Achilles; Samaras, Theodoros

2017-07-01

To assess general public exposure to electromagnetic fields from Long Term Evolution (LTE) base stations, measurements at 10 sites in Thessaloniki, Greece were performed. Results are compared with other mobile cellular networks currently in use. All exposure values satisfy the guidelines for general public exposure of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), as well as the reference levels by the Greek legislation at all sites. LTE electric field measurements were recorded up to 0.645 V/m. By applying the ICNIRP guidelines, the exposure ratio for all LTE signals is between 2.9 × 10-5 and 2.8 × 10-2. From the measurements results it is concluded that the average and maximum power density contribution of LTE downlink signals to the overall cellular networks signals are 7.8% and 36.7%, respectively. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Analysis of Patients' X-ray Exposure in 146 Percutaneous Radiologic Gastrostomies.

PubMed

Petersen, Tim-Ole; Reinhardt, Martin; Fuchs, Jochen; Gosch, Dieter; Surov, Alexey; Stumpp, Patrick; Kahn, Thomas; Moche, Michael

2017-09-01

significantly extends FT, but has little effect on the overall dose of the intervention. Due to the significantly higher X-ray exposure, the use of a CBCT as well as PRG-placements using CT should be limited to clinically absolutely necessary exceptions with strict indication. Key Points   · Fluoroscopically-guided PRG placements are interventions with low X-ray exposure.. · X-ray exposure from fluoroscopy is lower using flat panel detector systems as compared to image intensifier systems.. · The concomitant placement of an oro- or nasogastric probe extends the fluoroscopy time.. · Gastric probe placement is worthwhile to prevent the premature use of the significantly radiation-intensive CT.. · The use of the C-arm CT or the CT increases the beam exposure by 26 or 33 times, respectively.. · The PRG placement using C-arm CT and CT should only be performed in exceptional cases.. Citation Format · Petersen TO, Reinhardt M, Fuchs J et al. Analysis of Patients' X-ray Exposure in 146 Percutaneous Radiologic Gastrostomies. Fortschr Röntgenstr 2017; 189: 820 - 827. © Georg Thieme Verlag KG Stuttgart · New York.

Organic solvent exposure and contrast sensitivity: comparing men and women

PubMed Central

Oliveira, A.R.; Campos, A.A.; de Andrade, M.J.O.; de Medeiros, P.C.B.; dos Santos, N.A.

2018-01-01

The goal of this study was to compare the visual contrast sensitivity (CS) of men and women exposed and not exposed to organic solvents. Forty-six volunteers of both genders aged between 18 and 41 years (mean±SD=27.72±6.28) participated. Gas station attendants were exposed to gas containing 46.30 ppm of solvents at a temperature of 304±274.39 K, humidity of 62.25±7.59% and ventilation of 0.69±0.46 m/s (a passive gas chromatography-based sampling method was used considering the microclimate variables). Visual CS was measured via the psychophysical method of two-alternative forced choice using vertical sinusoidal gratings with spatial frequencies of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0, and 16.0 cpd (cycles per degree) and an average luminance of 34.4 cd/m2. The results showed that visual CS was significantly lower (P<0.05) in the following groups: i) exposed men compared to unexposed men at frequencies of 0.2, 0.5, 1.0, and 2.0 cpd; ii) exposed women compared to unexposed women at a frequency of 5.0 cpd; and iii) exposed women compared to exposed men at a frequency of 0.5 cpd, even at exposures below the tolerance limit (300 ppm). These results suggest that the visual CS of exposed men was impaired over a wider range of spatial frequencies than that of exposed women. This difference may have been due to the higher body fat content of women compared to that of men, suggesting that body fat in women can serve as a protective factor against neurotoxic effects. PMID:29340521

Comparing exposure assessment methods for traffic-related air pollution in an adverse pregnancy outcome study

PubMed Central

Wu, Jun; Wilhelm, Michelle; Chung, Judith; Ritz, Beate

2011-01-01

Background Previous studies reported adverse impacts of traffic-related air pollution exposure on pregnancy outcomes. Yet, little information exists on how effect estimates are impacted by the different exposure assessment methods employed in these studies. Objectives To compare effect estimates for traffic-related air pollution exposure and preeclampsia, preterm birth (gestational age less than 37 weeks), and very preterm birth (gestational age less than 30 weeks) based on four commonly-used exposure assessment methods. Methods We identified 81,186 singleton births during 1997–2006 at four hospitals in Los Angeles and Orange Counties, California. Exposures were assigned to individual subjects based on residential address at delivery using the nearest ambient monitoring station data [carbon monoxide (CO), nitrogen dioxide (NO2), nitric oxide (NO), nitrogen oxides (NOx), ozone (O3), and particulate matter less than 2.5 (PM2.5) or less than 10 (PM10) μm in aerodynamic diameter], both unadjusted and temporally-adjusted land-use regression (LUR) model estimates (NO, NO2, and NOx), CALINE4 line-source air dispersion model estimates (NOx and PM2.5), and a simple traffic-density measure. We employed unconditional logistic regression to analyze preeclampsia in our birth cohort, while for gestational age-matched risk sets with preterm and very preterm birth we employed conditional logistic regression. Results We observed elevated risks for preeclampsia, preterm birth, and very preterm birth from maternal exposures to traffic air pollutants measured at ambient stations (CO, NO, NO2, and NOx) and modeled through CALINE4 (NOx and PM2.5) and LUR (NO2 and NOx). Increased risk of preterm birth and very preterm birth were also positively associated with PM10 and PM2.5 air pollution measured at ambient stations. For LUR-modeled NO2 and NOx exposures, elevated risks for all the outcomes were observed in Los Angeles only – the region for which the LUR models were initially

Comparing exposure assessment methods for traffic-related air pollution in an adverse pregnancy outcome study.

PubMed

Wu, Jun; Wilhelm, Michelle; Chung, Judith; Ritz, Beate

2011-07-01

Previous studies reported adverse impacts of traffic-related air pollution exposure on pregnancy outcomes. Yet, little information exists on how effect estimates are impacted by the different exposure assessment methods employed in these studies. To compare effect estimates for traffic-related air pollution exposure and preeclampsia, preterm birth (gestational age less than 37 weeks), and very preterm birth (gestational age less than 30 weeks) based on four commonly used exposure assessment methods. We identified 81,186 singleton births during 1997-2006 at four hospitals in Los Angeles and Orange Counties, California. Exposures were assigned to individual subjects based on residential address at delivery using the nearest ambient monitoring station data [carbon monoxide (CO), nitrogen dioxide (NO(2)), nitric oxide (NO), nitrogen oxides (NO(x)), ozone (O(3)), and particulate matter less than 2.5 (PM(2.5)) or less than 10 (PM(10))μm in aerodynamic diameter], both unadjusted and temporally adjusted land-use regression (LUR) model estimates (NO, NO(2), and NO(x)), CALINE4 line-source air dispersion model estimates (NO(x) and PM(2.5)), and a simple traffic-density measure. We employed unconditional logistic regression to analyze preeclampsia in our birth cohort, while for gestational age-matched risk sets with preterm and very preterm birth we employed conditional logistic regression. We observed elevated risks for preeclampsia, preterm birth, and very preterm birth from maternal exposures to traffic air pollutants measured at ambient stations (CO, NO, NO(2), and NO(x)) and modeled through CALINE4 (NO(x) and PM(2.5)) and LUR (NO(2) and NO(x)). Increased risk of preterm birth and very preterm birth were also positively associated with PM(10) and PM(2.5) air pollution measured at ambient stations. For LUR-modeled NO(2) and NO(x) exposures, elevated risks for all the outcomes were observed in Los Angeles only--the region for which the LUR models were initially developed

Living network meta-analysis compared with pairwise meta-analysis in comparative effectiveness research: empirical study.

PubMed

Nikolakopoulou, Adriani; Mavridis, Dimitris; Furukawa, Toshi A; Cipriani, Andrea; Tricco, Andrea C; Straus, Sharon E; Siontis, George C M; Egger, Matthias; Salanti, Georgia

2018-02-28

To examine whether the continuous updating of networks of prospectively planned randomised controlled trials (RCTs) ("living" network meta-analysis) provides strong evidence against the null hypothesis in comparative effectiveness of medical interventions earlier than the updating of conventional, pairwise meta-analysis. Empirical study of the accumulating evidence about the comparative effectiveness of clinical interventions. Database of network meta-analyses of RCTs identified through searches of Medline, Embase, and the Cochrane Database of Systematic Reviews until 14 April 2015. Network meta-analyses published after January 2012 that compared at least five treatments and included at least 20 RCTs. Clinical experts were asked to identify in each network the treatment comparison of greatest clinical interest. Comparisons were excluded for which direct and indirect evidence disagreed, based on side, or node, splitting test (P<0.10). Cumulative pairwise and network meta-analyses were performed for each selected comparison. Monitoring boundaries of statistical significance were constructed and the evidence against the null hypothesis was considered to be strong when the monitoring boundaries were crossed. A significance level was defined as α=5%, power of 90% (β=10%), and an anticipated treatment effect to detect equal to the final estimate from the network meta-analysis. The frequency and time to strong evidence was compared against the null hypothesis between pairwise and network meta-analyses. 49 comparisons of interest from 44 networks were included; most (n=39, 80%) were between active drugs, mainly from the specialties of cardiology, endocrinology, psychiatry, and rheumatology. 29 comparisons were informed by both direct and indirect evidence (59%), 13 by indirect evidence (27%), and 7 by direct evidence (14%). Both network and pairwise meta-analysis provided strong evidence against the null hypothesis for seven comparisons, but for an additional 10

Space Shuttle and Space Station Radio Frequency (RF) Exposure Analysis

NASA Technical Reports Server (NTRS)

Hwu, Shian U.; Loh, Yin-Chung; Sham, Catherine C.; Kroll, Quin D.

2005-01-01

This paper outlines the modeling techniques and important parameters to define a rigorous but practical procedure that can verify the compliance of RF exposure to the NASA standards for astronauts and electronic equipment. The electromagnetic modeling techniques are applied to analyze RF exposure in Space Shuttle and Space Station environments with reasonable computing time and resources. The modeling techniques are capable of taking into account the field interactions with Space Shuttle and Space Station structures. The obtained results illustrate the multipath effects due to the presence of the space vehicle structures. It's necessary to include the field interactions with the space vehicle in the analysis for an accurate assessment of the RF exposure. Based on the obtained results, the RF keep out zones are identified for appropriate operational scenarios, flight rules and necessary RF transmitter constraints to ensure a safe operating environment and mission success.

Comparing exposure metrics for classifying ‘dangerous heat’ in heat wave and health warning systems

PubMed Central

Zhang, Kai; Rood, Richard B.; Michailidis, George; Oswald, Evan M.; Schwartz, Joel D.; Zanobetti, Antonella; Ebi, Kristie L.; O’Neill, Marie S.

2012-01-01

Heat waves have been linked to excess mortality and morbidity, and are projected to increase in frequency and intensity with a warming climate. This study compares exposure metrics to trigger heat wave and health warning systems (HHWS), and introduces a novel multi-level hybrid clustering method to identify potential dangerously hot days. Two-level and three-level hybrid clustering analysis as well as common indices used to trigger HHWS, including spatial synoptic classification (SSC); and 90th, 95th, and 99th percentiles of minimum and relative minimum temperature (using a 10 day reference period), were calculated using a summertime weather dataset in Detroit from 1976 to 2006. The days classified as ‘hot’ with hybrid clustering analysis, SSC, minimum and relative minimum temperature methods differed by method type. SSC tended to include the days with, on average, 2.6 °C lower daily minimum temperature and 5.3 °C lower dew point than days identified by other methods. These metrics were evaluated by comparing their performance in predicting excess daily mortality. The 99th percentile of minimum temperature was generally the most predictive, followed by the three-level hybrid clustering method, the 95th percentile of minimum temperature, SSC and others. Our proposed clustering framework has more flexibility and requires less substantial meteorological prior information than the synoptic classification methods. Comparison of these metrics in predicting excess daily mortality suggests that metrics thought to better characterize physiological heat stress by considering several weather conditions simultaneously may not be the same metrics that are better at predicting heat-related mortality, which has significant implications in HHWSs. PMID:22673187

Exposure to isoflavone-containing soy products and endothelial function: a Bayesian meta-analysis of randomized controlled trials.

PubMed

Beavers, D P; Beavers, K M; Miller, M; Stamey, J; Messina, M J

2012-03-01

To determine whether and to what degree exposure to isoflavone-containing soy products affects EF. Endothelial dysfunction has been identified as an independent coronary heart disease risk factor and a strong predictor of long-term cardiovascular morbidity and mortality. Data on the effects of exposure to isoflavone-containing soy products on EF are conflicting. A comprehensive literature search was conducted using the PUBMED database (National Library of Medicine, Bethesda, MD) inclusively through August 21, 2009 on RCTs using the keywords: soy, isoflavone, phytoestrogen, EF, flow mediated vasodilation, and FMD. A Bayesian meta-analysis was conducted to provide a comprehensive account of the effect of isoflavone-containing soy products on EF, as measured by FMD. A total of 17 RCTs were selected as having sufficient data for study inclusion. The overall mean absolute change in FMD (95% Bayesian CI) for isoflavone-containing soy product interventions was 1.15% (-0.52, 2.75). When the effects of separate interventions were considered, the treatment effect for isolated isoflavones was 1.98% (0.07, 3.97) compared to 0.72% (-1.39, 2.90) for isoflavone-containing soy protein. The models were not improved when considering study-specific effects such as cuff measurement location, prescribed dietary modification, and impaired baseline FMD. Cumulative evidence from the RCTs included in this meta-analysis indicates that exposure to soy isoflavones can modestly, but significantly, improve EF as measured by FMD. Therefore, exposure to isoflavone supplements may beneficially influence vascular health. Copyright © 2010 Elsevier B.V. All rights reserved.

Quantitative proteomic analysis of the brainstem following lethal sarin exposure.

PubMed

Meade, Mitchell L; Hoffmann, Andrea; Makley, Meghan K; Snider, Thomas H; Schlager, John J; Gearhart, Jeffery M

2015-06-22

The brainstem represents a major tissue area affected by sarin organophosphate poisoning due to its function in respiratory and cardiovascular control. While the acute toxic effects of sarin on brainstem-related responses are relatively unknown, other brain areas e.g., cortex or cerebellum, have been studied more extensively. The study objective was to analyze the guinea pig brainstem toxicology response following sarin (2×LD50) exposure by proteome pathway analysis to gain insight into the complex regulatory mechanisms that lead to impairment of respiratory and cardiovascular control. Guinea pig exposure to sarin resulted in the typical acute behavior/physiology outcomes with death between 15 and 25min. In addition, brain and blood acetylcholinesterase activity was significantly reduced in the presence of sarin to 95%, and 89%, respectively, of control values. Isobaric-tagged (iTRAQ) liquid chromatography tandem mass spectrometry (LC-MS/MS) identified 198 total proteins of which 23% were upregulated, and 18% were downregulated following sarin exposure. Direct gene ontology (GO) analysis revealed a sarin-specific broad-spectrum proteomic profile including glutamate-mediated excitotoxicity, calcium overload, energy depletion responses, and compensatory carbohydrate metabolism, increases in ROS defense, DNA damage and chromatin remodeling, HSP response, targeted protein degradation (ubiquitination) and cell death response. With regards to the sarin-dependent effect on respiration, our study supports the potential interference of sarin with CO2/H(+) sensitive chemoreceptor neurons of the brainstem retrotrapezoid nucleus (RTN) that send excitatory glutamergic projections to the respiratory centers. In conclusion, this study gives insight into the brainstem broad-spectrum proteome following acute sarin exposure and the gained information will assist in the development of novel countermeasures. Published by Elsevier B.V.

EXPOSURE ASSESSMENT AND FUTURE DIRECTIONS IN EXPOSURE SCIENCE

EPA Science Inventory

Exposure is the contact between a stressor and a human or ecological receptor. Risk analysis step in which receptor interaction with the exposure stressor of concern is evaluated. To assess exposure to a particular stressor we need to know - Properties of the stressor; Sources, p...

High-Throughput Models for Exposure-Based Chemical ...

EPA Pesticide Factsheets

The United States Environmental Protection Agency (U.S. EPA) must characterize potential risks to human health and the environment associated with manufacture and use of thousands of chemicals. High-throughput screening (HTS) for biological activity allows the ToxCast research program to prioritize chemical inventories for potential hazard. Similar capabilities for estimating exposure potential would support rapid risk-based prioritization for chemicals with limited information; here, we propose a framework for high-throughput exposure assessment. To demonstrate application, an analysis was conducted that predicts human exposure potential for chemicals and estimates uncertainty in these predictions by comparison to biomonitoring data. We evaluated 1936 chemicals using far-field mass balance human exposure models (USEtox and RAIDAR) and an indicator for indoor and/or consumer use. These predictions were compared to exposures inferred by Bayesian analysis from urine concentrations for 82 chemicals reported in the National Health and Nutrition Examination Survey (NHANES). Joint regression on all factors provided a calibrated consensus prediction, the variance of which serves as an empirical determination of uncertainty for prioritization on absolute exposure potential. Information on use was found to be most predictive; generally, chemicals above the limit of detection in NHANES had consumer/indoor use. Coupled with hazard HTS, exposure HTS can place risk earlie

Type of alcohol drink and exposure to violence: an emergency department study.

PubMed

Chavira, Cynthia; Bazargan-Hejazi, Shahrzad; Lin, Johnny; del Pino, Homero E; Bazargan, Mohsen

2011-08-01

We compared the prevalence of exposure to violence across different types of alcohol consumed and the association between the type of alcohol consumed and exposure to violence. A cross-sectional analysis of data collected from a sample of 295 Emergency Department (ED) patients identified as having an alcohol problem. Outcome measure include exposure to violence, and the main study predictor was "type of alcoholic drink" including: malt liquor beer (MLB), regular beer, wine cooler, wine, fortified wine or hard liquor. Using logistic regression analysis, ED patients who drank MLB in combination with other types of alcohol increased their odds of being both threatened and physically attacked by 8.5 compared to ED patients who drank other types of alcohol. Being female increased the odds of being both threatened and physically attacked by 2.5 and using illicit drugs increased the odds by 3.8. Analysis of covariance and estimated marginal means revealed that ED patients who only drank MLB had a higher exposure to violence compared to non-MLB drinkers, and that female illicit drug users who drank MLB in combination with other types of alcohol had the highest exposure to violence. MLB was identified as a predictor of the amount of exposure to violence and in particular, that the use of malt liquor beer in combination with other types of alcohol increased the risk of being both threatened and physically attacked. Implications for ED and community interventions are suggested.

Risk Analysis of UVB Exposure in Canadian Inland Waters

NASA Astrophysics Data System (ADS)

Molot, L. A.; Keller, W.; Leavitt, P. R.; Robarts, R. D.; Waiser, M. J.; Arts, M. T.; Clair, T. A.; Pienitz, R.; Yan, N. D.; McNicol, D. K.; Prairie, Y.; Dillon, P. J.; Macrae, M.; Bello, R.; Nordin, R. N.; Curtis, P. J.

2004-05-01

Exposure to UVB (290-320 nm) harms some aquatic taxa and processes. With the restoration of pre-industrial ozone levels still some years away and the possibility that climate change might lower dissolved organic matter (DOM) concentrations and thus lead to increased exposure, evaluating the extent to which freshwater environments in Canada are at risk is warranted. First, the distribution of a UVB-sensitive zooplankton genus, Daphnia, was examined as a function of DOM and maximum depth (Zmax) in 258 lakes and ponds in Ontario and the eastern U.S. to determine whether UVB exposure restricts its distribution. Our results indicate that the distribution of Daphnia is not restricted by exposure to UVB with the possible exception of very clear, shallow systems underrepresented in the surveys. Secondly, the maximum depth of UVB transmission (the depth at which 1% of surface irradiance at 320 nm occurs, Z320,1%) was compared to Zmax in over 900 aquatic systems in different Canadian ecozones to determine the proportion of optically clear systems (Zmax< Z320,1%) and the extent to which systems that are not clear may become so (`at risk') should they lose 50% of their DOM. The proportion of systems deemed optically clear is low (<6%) across Canada with the exception of three ecozones between 13% and 20%. The proportion of systems deemed at risk is 0% in most regions with 5--9% in five regions from four ecozones. These results suggest that DOM levels are adequate to prevent large-scale loss of sensitive species from direct exposure to elevated UVB in most regions of Canada.

Evaluation and recommendation of sensitivity analysis methods for application to Stochastic Human Exposure and Dose Simulation models.

PubMed

Mokhtari, Amirhossein; Christopher Frey, H; Zheng, Junyu

2006-11-01

Sensitivity analyses of exposure or risk models can help identify the most significant factors to aid in risk management or to prioritize additional research to reduce uncertainty in the estimates. However, sensitivity analysis is challenged by non-linearity, interactions between inputs, and multiple days or time scales. Selected sensitivity analysis methods are evaluated with respect to their applicability to human exposure models with such features using a testbed. The testbed is a simplified version of a US Environmental Protection Agency's Stochastic Human Exposure and Dose Simulation (SHEDS) model. The methods evaluated include the Pearson and Spearman correlation, sample and rank regression, analysis of variance, Fourier amplitude sensitivity test (FAST), and Sobol's method. The first five methods are known as "sampling-based" techniques, wheras the latter two methods are known as "variance-based" techniques. The main objective of the test cases was to identify the main and total contributions of individual inputs to the output variance. Sobol's method and FAST directly quantified these measures of sensitivity. Results show that sensitivity of an input typically changed when evaluated under different time scales (e.g., daily versus monthly). All methods provided similar insights regarding less important inputs; however, Sobol's method and FAST provided more robust insights with respect to sensitivity of important inputs compared to the sampling-based techniques. Thus, the sampling-based methods can be used in a screening step to identify unimportant inputs, followed by application of more computationally intensive refined methods to a smaller set of inputs. The implications of time variation in sensitivity results for risk management are briefly discussed.

Exposure to UV radiation and risk of Hodgkin lymphoma: a pooled analysis

PubMed Central

Glaser, Sally L.; Schupp, Clayton W.; Ekström Smedby, Karin; de Sanjosé, Silvia; Kane, Eleanor; Melbye, Mads; Forétova, Lenka; Maynadié, Marc; Staines, Anthony; Becker, Nikolaus; Nieters, Alexandra; Brennan, Paul; Boffetta, Paolo; Cocco, Pierluigi; Glimelius, Ingrid; Clavel, Jacqueline; Hjalgrim, Henrik; Chang, Ellen T.

2013-01-01

Ultraviolet radiation (UVR) exposure has been inversely associated with Hodgkin lymphoma (HL) risk, but only inconsistently, only in a few studies, and without attention to HL heterogeneity. We conducted a pooled analysis of HL risk focusing on type and timing of UVR exposure and on disease subtypes by age, histology, and tumor-cell Epstein-Barr virus (EBV) status. Four case-control studies contributed 1320 HL cases and 6381 controls. We estimated lifetime, adulthood, and childhood UVR exposure and history of sunburn and sunlamp use. We used 2-stage estimation with mixed-effects models and weighted pooled effect estimates by inverse marginal variances. We observed statistically significant inverse associations with HL risk for UVR exposures during childhood and adulthood, sunburn history, and sunlamp use, but we found no significant dose-response relationships. Risks were significant only for EBV-positive HL (pooled odds ratio, 0.56; 95% confidence interval, 0.35 to 0.91 for the highest overall UVR exposure category), with a significant linear trend for overall exposure (P = .03). Pooled relative risk estimates were not heterogeneous across studies. Increased UVR exposure may protect against HL, particularly EBV-positive HL. Plausible mechanisms involving UVR induction of regulatory T cells or the cellular DNA damage response suggest opportunities for new prevention targets. PMID:24016459

Comparison of electric field exposure monitoring instrumentation. Final report

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

Bracken, T.D.

1985-06-01

Electric field exposure monitoring instrumentation was compared and evaluated during three days of tests performed in 60-Hz electric fields. A conducting vest exposure meter and a small electric field exposure meter (EFEM) located in a shirt pocket, arm band or hard hat were compared in a series of static and dynamic tests. In some tests, the devices were worn simultaneously without interference to provide separate measures of identical exposure. Tests with stationary subjects wearing the instruments were used to measure the effects of grounding, and to establish the meter response in a standard posture for each subject. Dynamic occupational exposuremore » simulations were used to compare accumulated measurements of exposure between instruments and to compare measurements with predicted exposures. The simulations were based on analysis of the work-related behavior of substation electricians and operators. Electrician's tasks at ground level and in a bucket truck were simulated near an energized test line. A simulated substation inspection was performed in a 230 kV substation. The exposure measurements demonstrated an overall consistency between the meters. The vest demonstrated less intersubject variability and less detailed exposure characterization. Measurements with the shirt pocket EFEM were below those made with the vest and with the EFEM in other locations. Insulation provided by shoe soles appeared to be the largest factor in reducing measured exposures during the substation inspection below those predicted from the unperturbed field. Improvements in meter design and additional measurements are suggested. 11 refs., 20 figs., 28 tabs.« less

Mediation analysis allowing for exposure-mediator interactions and causal interpretation: theoretical assumptions and implementation with SAS and SPSS macros

PubMed Central

Valeri, Linda; VanderWeele, Tyler J.

2012-01-01

Mediation analysis is a useful and widely employed approach to studies in the field of psychology and in the social and biomedical sciences. The contributions of this paper are several-fold. First we seek to bring the developments in mediation analysis for non linear models within the counterfactual framework to the psychology audience in an accessible format and compare the sorts of inferences about mediation that are possible in the presence of exposure-mediator interaction when using a counterfactual versus the standard statistical approach. Second, the work by VanderWeele and Vansteelandt (2009, 2010) is extended here to allow for dichotomous mediators and count outcomes. Third, we provide SAS and SPSS macros to implement all of these mediation analysis techniques automatically and we compare the types of inferences about mediation that are allowed by a variety of software macros. PMID:23379553

RECENT DEVELOPMENTS IN EXHALED BREATH ANALYSIS AND HUMAN EXPOSURE ASSESSMENT RESEARCH

EPA Science Inventory

This presentation will explore historical and newly emerging methods for the collection and analysis of exhaled breath for use in environmental exposure assessment studies. We will discuss their applicability and limitations with respect to environmental research. Particular em...

Safety and tolerability of exenatide twice daily in patients with type 2 diabetes: integrated analysis of 5594 patients from 19 placebo-controlled and comparator-controlled clinical trials

PubMed Central

MacConell, Leigh; Brown, Carl; Gurney, Kate; Han, Jenny

2012-01-01

Background Exenatide twice daily is a first-in-class glucagon-like peptide receptor agonist approved for the treatment of type 2 diabetes. The objective of this analysis was to evaluate the safety profile of exenatide twice daily and to compare its profile with that of a pooled comparator (placebo and insulin) in patients with type 2 diabetes. Methods Data from 19 completed, randomized, controlled clinical trials of exenatide twice daily (5 μg and 10 μg) were pooled and analyzed; the pooled data included 5594 intent-to-treat patients who were followed for 12–52 weeks. Incidence rates, exposure-adjusted incidence rates, and 95% confidence intervals around risk differences between groups were calculated. Results Baseline demographics and exposure time were comparable between groups (exenatide, N = 3261; pooled comparator, N = 2333; mean exposure time 166–171 days). Transient, mild- to-moderate nausea was the most frequent adverse event with exenatide (36.9% versus 8.3% in the pooled comparator). The incidence of hypoglycemia (minor or major) with concomitant sulfonylurea (exenatide 26.5%, pooled comparator 20.7%) was higher than that without sulfonylurea (exenatide 3.1%, pooled comparator 2.7%) in all groups. Serious adverse events, discontinuations due to serious adverse events, and deaths were reported with similar frequency in the exenatide and pooled comparator groups. Composite exposure-adjusted incidence rates were not statistically different between groups for pancreatitis, renal impairment, or major adverse cardiac events; there was a difference in incidence rates for benign thyroid neoplasm (0.3% versus 0%). Conclusion Overall, this analysis, representing over 1500 patient-years of exposure, demonstrated that exenatide twice daily was safe and generally well tolerated in patients with type 2 diabetes. The incidence of most adverse events, including serious adverse events, was similar in both exenatide-treated and comparator-treated patients. The most

Comparative analysis of the countermeasures taken to mitigate exposure of the public to radioiodine following the Chernobyl and Fukushima accidents: lessons from both accidents.

PubMed

Uyba, Vladimir; Samoylov, Alexander; Shinkarev, Sergey

2018-04-01

In the case of a severe radiation accident at a nuclear power station, the most important radiation hazard for the public is internal exposure of the thyroid to radioiodine. The purposes of this paper were (i) to compare countermeasures conducted (following the Chernobyl and Fukushima accidents) aimed at mitigation of exposure to the thyroid for the public, (ii) to present comparative estimates of doses to the thyroid and (iii) to derive lessons from the two accidents. The scale and time of countermeasures applied in the early phase of the accidents (sheltering, evacuation, and intake of stable iodine to block the thyroid) and at a later time (control of 131I concentration in foodstuffs) have been described. After the Chernobyl accident, the estimation of the thyroid doses for the public was mainly based on direct thyroid measurements of ~400 000 residents carried out within the first 2 months. The highest estimates of thyroid doses to children reached 50 Gy. After the Fukushima accident, the estimation of thyroid doses was based on radioecological models due to a lack of direct thyroid measurements (only slightly more than 1000 residents were measured). The highest estimates of thyroid doses to children were a few hundred mGy. Following the Chernobyl accident, ingestion of 131I through cows' milk was the dominant pathway. Following the Fukushima accident, it appears that inhalation of contaminated air was the dominant pathway. Some lessons learned following the Chernobyl and Fukushima accidents have been presented in this paper.

Occupational exposure to asbestos and cardiovascular related diseases: A meta-analysis

PubMed Central

Rong, Yi; Luo, Xin; Zhang, Zhihong; Cui, Xiuqing; Liu, Yuewei; Chen, Weihong

2015-01-01

Asbestos has become one of the leading causes of death among occupational workers in the world. The association between asbestos and cardiovascular disease is less reported. We performed a meta-analysis to quantify the association between asbestos exposure and the mortality of cardiovascular related diseases. We performed a systematic review in the PubMed database before December 2014. All cohort studies citing the standardized mortality ratio (SMR) of cardiovascular related diseases in workers exposed to asbestos were collected. We then calculated the pooled standardized mortality ratios of such diseases. Sixteen studies were included. The combined results from all studies indicated the pooled SMR estimate for cardiovascular related diseases was 1.11 (95% CI, 1.01–1.22). This meta-analysis showed that asbestos exposure significantly increased the risk of cardiovascular related diseases in exposed workers. PMID:26844169

Effect of occupational exposures on lung cancer susceptibility: a study of gene-environment interaction analysis.

PubMed

Malhotra, Jyoti; Sartori, Samantha; Brennan, Paul; Zaridze, David; Szeszenia-Dabrowska, Neonila; Świątkowska, Beata; Rudnai, Peter; Lissowska, Jolanta; Fabianova, Eleonora; Mates, Dana; Bencko, Vladimir; Gaborieau, Valerie; Stücker, Isabelle; Foretova, Lenka; Janout, Vladimir; Boffetta, Paolo

2015-03-01

Occupational exposures are known risk factors for lung cancer. Role of genetically determined host factors in occupational exposure-related lung cancer is unclear. We used genome-wide association (GWA) data from a case-control study conducted in 6 European countries from 1998 to 2002 to identify gene-occupation interactions and related pathways for lung cancer risk. GWA analysis was performed for each exposure using logistic regression and interaction term for genotypes, and exposure was included in this model. Both SNP-based and gene-based interaction P values were calculated. Pathway analysis was performed using three complementary methods, and analyses were adjusted for multiple comparisons. We analyzed 312,605 SNPs and occupational exposure to 70 agents from 1,802 lung cancer cases and 1,725 cancer-free controls. Mean age of study participants was 60.1 ± 9.1 years and 75% were male. Largest number of significant associations (P ≤ 1 × 10(-5)) at SNP level was demonstrated for nickel, brick dust, concrete dust, and cement dust, and for brick dust and cement dust at the gene-level (P ≤ 1 × 10(-4)). Approximately 14 occupational exposures showed significant gene-occupation interactions with pathways related to response to environmental information processing via signal transduction (P < 0.001 and FDR < 0.05). Other pathways that showed significant enrichment were related to immune processes and xenobiotic metabolism. Our findings suggest that pathways related to signal transduction, immune process, and xenobiotic metabolism may be involved in occupational exposure-related lung carcinogenesis. Our study exemplifies an integrative approach using pathway-based analysis to demonstrate the role of genetic variants in occupational exposure-related lung cancer susceptibility. Cancer Epidemiol Biomarkers Prev; 24(3); 570-9. ©2015 AACR. ©2015 American Association for Cancer Research.

Personal Breathing Zone Exposures among Hot-Mix Asphalt Paving Workers; Preliminary Analysis for Trends and Analysis of Work Practices That Resulted in the Highest Exposure Concentrations

PubMed Central

Osborn, Linda V.; Snawder, John E.; Kriech, Anthony J.; Cavallari, Jennifer M.; McClean, Michael D.; Herrick, Robert F.; Blackburn, Gary R.; Olsen, Larry D.

2015-01-01

An exposure assessment of hot-mix asphalt (HMA) paving workers was conducted to determine which of four exposure scenarios impacted worker exposure and dose. Goals of this report are to present the personal-breathing zone (PBZ) data, discuss the impact of substituting the releasing/cleaning agent, and discuss work practices that resulted in the highest exposure concentration for each analyte. One-hundred-seven PBZ samples were collected from HMA paving workers on days when diesel oil was used as a releasing/cleaning agent. An additional 36 PBZ samples were collected on days when B-100 (100% biodiesel, containing no petroleum-derived products) was used as a substitute releasing/cleaning agent. Twenty-four PBZ samples were collected from a reference group of concrete workers, who also worked in outdoor construction but had no exposure to asphalt emissions. Background and field blank samples were also collected daily. Total particulates and the benzene soluble fraction were determined gravimetrically. Total organic matter was determined using gas chromatography (GC) with flame ionization detection and provided qualitative information about other exposure sources contributing to worker exposure besides asphalt emissions. Thirty-three individual polycyclic aromatic compounds (PACs) were determined using GC with time-offlight mass spectrometry; results were presented as either the concentration of an individual PAC or a summation of the individual PACs containing either 2- to 3-rings or 4- to 6-rings. Samples were also screened for PACs containing 4- to 6-rings using fluorescence spectroscopy. Arithmetic means, medians, and box plots of the PBZ data were used to evaluate trends in the data. Box plots illustrating the diesel oil results were more variable than the B-100. Also, the highest diesel oil results were much higher in concentration than the highest B-100 results. An analysis of the highest exposure results and field notes revealed a probable association between

Personal breathing zone exposures among hot-mix asphalt paving workers; preliminary analysis for trends and analysis of work practices that resulted in the highest exposure concentrations.

PubMed

Osborn, Linda V; Snawder, John E; Kriech, Anthony J; Cavallari, Jennifer M; McClean, Michael D; Herrick, Robert F; Blackburn, Gary R; Olsen, Larry D

2013-01-01

An exposure assessment of hot-mix asphalt (HMA) paving workers was conducted to determine which of four exposure scenarios impacted worker exposure and dose. Goals of this report are to present the personal-breathing zone (PBZ) data, discuss the impact of substituting the releasing/cleaning agent, and discuss work practices that resulted in the highest exposure concentration for each analyte. One-hundred-seven PBZ samples were collected from HMA paving workers on days when diesel oil was used as a releasing/cleaning agent. An additional 36 PBZ samples were collected on days when B-100 (100% biodiesel, containing no petroleum-derived products) was used as a substitute releasing/cleaning agent. Twenty-four PBZ samples were collected from a reference group of concrete workers, who also worked in outdoor construction but had no exposure to asphalt emissions. Background and field blank samples were also collected daily. Total particulates and the benzene soluble fraction were determined gravimetrically. Total organic matter was determined using gas chromatography (GC) with flame ionization detection and provided qualitative information about other exposure sources contributing to worker exposure besides asphalt emissions. Thirty-three individual polycyclic aromatic compounds (PACs) were determined using GC with time-of-flight mass spectrometry; results were presented as either the concentration of an individual PAC or a summation of the individual PACs containing either 2- to 3-rings or 4- to 6-rings. Samples were also screened for PACs containing 4- to 6-rings using fluorescence spectroscopy. Arithmetic means, medians, and box plots of the PBZ data were used to evaluate trends in the data. Box plots illustrating the diesel oil results were more variable than the B-100. Also, the highest diesel oil results were much higher in concentration than the highest B-100 results. An analysis of the highest exposure results and field notes revealed a probable association between

Exposure of the examiner to radiation during myelography versus radiculography and root block: A comparative study.

PubMed

Yamane, Kentaro; Kai, Nobuo; Miyamoto, Tadashi; Matsushita, Tomohiro

2017-03-01

Exposure to radiation over many years prompts concerns regarding potential health-related effects, particularly the incidence of cataracts and the development of cancer. The purpose of this study was to examine and compare the exposure of the examiner to radiation during myelography versus radiculography and root block. A total of 114 examinations were performed in our institute in the 6 months. Sixty-two examinations were performed during myelography in the first 3 months (MG group), while 52 were performed during radiculography and root block in the last 3 months (RB group). The examiner wore a torso protector, a neck protector, radiation protection gloves, and radiation protection glasses. Optically stimulated luminescence (OSL) dosimeter badges were placed on both the inside and the outside of each protector. The dosimeters were exchanged every month. Radiation doses (mSv) were measured as the integrated radiation quantity every month from the OSL dosimeters. The effective dose and the equivalent doses of hand, skin, and eyes were investigated. The mean equivalent doses were significantly lower outside the neck, torso, eye protectors, and inside the torso protector in the RB group than in the MG group. Conversely, the mean equivalent dose was significantly lower outside the hand protector in the MG group than in the RB group. The use of a neck protector significantly decreased the effective dose compared to the non-use of a neck protector in the RB group. The present study showed the standard radiation exposure to the examiner during myelography, radiculography, and root block. Receiving full protection including a neck protector and protection gloves is an easy and reliable means to reduce radiation exposure. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Comparing Trauma Exposure, Mental Health Needs, and Service Utilization Across Clinical Samples of Refugee, Immigrant, and U.S.-Origin Children.

PubMed

Betancourt, Theresa S; Newnham, Elizabeth A; Birman, Dina; Lee, Robert; Ellis, B Heidi; Layne, Christopher M

2017-06-01

Most mental health services for trauma-exposed children and adolescents were not originally developed for refugees. Information is needed to help clinicians design services to address the consequences of trauma in refugee populations. We compared trauma exposure, psychological distress, and mental health service utilization among children and adolescents of refugee-origin, immigrant-origin, and U.S.-origin referred for assessment and treatment by U.S. providers in the National Child Traumatic Stress Network (NCTSN). We used propensity score matching to compare trauma profiles, mental health needs, and service use across three groups. Our sample comprised refugee-origin youth (n = 60, 48.3% female, mean age = 13.07 years) and propensity-matched samples of immigrant-origin youth (n = 143, 60.8% female, mean age = 13.26 years), and U.S.-origin youth (n = 140, 56.1% female, mean age = 12.11 years). On average, there were significantly more types of trauma exposure among refugee youth than either U.S.-origin youth (p < .001) or immigrant youth (p ≤ .001). Compared with U.S.-origin youth, refugee youth had higher rates of community violence exposure, dissociative symptoms, traumatic grief, somatization, and phobic disorder.  In contrast, the refugee group had comparably lower rates of substance abuse and oppositional defiant disorder (ps ranging from .030 to < .001).This clinic-referred sample of refugee-origin youth presented with distinct patterns of trauma exposure, distress symptoms, and service needs that merit consideration in services planning. Copyright © 2017 International Society for Traumatic Stress Studies.

Association Between Cd Exposure and Risk of Prostate Cancer

PubMed Central

Ju-Kun, Song; Yuan, Dong-Bo; Rao, Hao-Fu; Chen, Tian-Fei; Luan, Bo-Shi; Xu, Xiao-Ming; Jiang, Fu-Neng; Zhong, Wei-De; Zhu, Jian-Guo

2016-01-01

Abstract Several observational studies on the association between Cd exposure and risk of prostate cancer have yielded inconsistent results. To address this issue, we conducted a meta-analysis to evaluate the correlation between Cd exposure and risk of prostate cancer. Relevant studies in PubMed and Embase databases were retrieved until October 2015. We compared the highest and lowest meta-analyses to quantitatively evaluate the relationship between Cd exposure and risk of prostate cancer. Summary estimates were obtained using a random-effects model. In the general population, high Cd exposure was not associated with increased prostate cancer (OR 1.21; 95% CI 0.91–1.64), whereas the combined standardized mortality ratio of the association between Cd exposure and risk of prostate cancer was 1.66 (95% CI 1.10–2.50) in populations exposed to occupational Cd. In addition, high D-Cd intake (OR 1.07; 95% CI 0.96–1.20) and U-Cd concentration (OR 0.86; 95% CI 0.48–1.55) among the general population was not related to the increased risk of prostate cancer. In the dose analysis, the summary relative risk was 1.07 (95% CI 0.73–1.57) for each 0.5 μg/g creatinine increase in U-Cd and 1.02 (95% CI 0.99–1.06) for each 10 μg/day increase of dietary Cd intake. However, compared with nonoccupational exposure, high occupational Cd exposure may be associated with the increased risk of prostate cancer. This meta-analysis suggests high Cd exposure as a risk factor for prostate cancer in occupational rather than nonoccupational populations. However, these results should be carefully interpreted because of the significant heterogeneity among studies. Additional large-scale and high-quality prospective studies are needed to confirm the association between Cd exposure and risk of prostate cancer. PMID:26871808

Occupational exposure to HDI: progress and challenges in biomarker analysis.

PubMed

Flack, Sheila L; Ball, Louise M; Nylander-French, Leena A

2010-10-01

1,6-Hexamethylene diisocyanate (HDI) is extensively used in the automotive repair industry and is a commonly reported cause of occupational asthma in industrialized populations. However, the exact pathological mechanism remains uncertain. Characterization and quantification of biomarkers resulting from HDI exposure can fill important knowledge gaps between exposure, susceptibility, and the rise of immunological reactions and sensitization leading to asthma. Here, we discuss existing challenges in HDI biomarker analysis including the quantification of N-acetyl-1,6-hexamethylene diamine (monoacetyl-HDA) and N,N'-diacetyl-1,6-hexamethylene diamine (diacetyl-HDA) in urine samples based on previously established methods for HDA analysis. In addition, we describe the optimization of reaction conditions for the synthesis of monoacetyl-HDA and diacetyl-HDA, and utilize these standards for the quantification of these metabolites in the urine of three occupationally exposed workers. Diacetyl-HDA was present in untreated urine at 0.015-0.060 μg/l. Using base hydrolysis, the concentration range of monoacetyl-HDA in urine was 0.19-2.2 μg/l, 60-fold higher than in the untreated samples on average. HDA was detected only in one sample after base hydrolysis (0.026 μg/l). In contrast, acid hydrolysis yielded HDA concentrations ranging from 0.36 to 10.1 μg/l in these three samples. These findings demonstrate HDI metabolism via N-acetylation metabolic pathway and protein adduct formation resulting from occupational exposure to HDI. Copyright © 2010 Elsevier B.V. All rights reserved.

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

PubMed Central

Kurth, Laura; Doney, Brent; Weinmann, Sheila

2017-01-01

Objectives To compare the occupational exposure levels assigned by our National Institute for Occupational Safety and Health chronic obstructive pulmonary disease-specific job exposure matrix (NIOSH COPD JEM) and by expert evaluation of detailed occupational information for various jobs held by members of an integrated health plan in the Northwest USA. Methods We analysed data from a prior study examining COPD and occupational exposures. Jobs were assigned exposure levels using 2 methods: (1) the COPD JEM and (2) expert evaluation. Agreement (Cohen’s κ coefficients), sensitivity and specificity were calculated to compare exposure levels assigned by the 2 methods for 8 exposure categories. Results κ indicated slight to moderate agreement (0.19–0.51) between the 2 methods and was highest for organic dust and overall exposure. Sensitivity of the matrix ranged from 33.9% to 68.5% and was highest for sensitisers, diesel exhaust and overall exposure. Specificity ranged from 74.7% to 97.1% and was highest for fumes, organic dust and mineral dust. Conclusions This COPD JEM was compared with exposures assigned by experts and offers a generalisable approach to assigning occupational exposure. PMID:27777373

Variability in exposure to ambient ultrafine particles in urban schools: Comparative assessment between Australia and Spain.

PubMed

Mazaheri, Mandana; Reche, Cristina; Rivas, Ioar; Crilley, Leigh R; Álvarez-Pedrerol, Mar; Viana, Mar; Tobias, Aurelio; Alastuey, Andrés; Sunyer, Jordi; Querol, Xavier; Morawska, Lidia

2016-03-01

Ambient ultrafine particle number concentrations (PNC) have inhomogeneous spatio-temporal distributions and depend on a number of different urban factors, including background conditions and distant sources. This paper quantitatively compares exposure to ambient ultrafine particles at urban schools in two cities in developed countries, with high insolation climatic conditions, namely Brisbane (Australia) and Barcelona (Spain). The analysis used comprehensive indoor and outdoor air quality measurements at 25 schools in Brisbane and 39 schools in Barcelona. PNC modes were analysed with respect to ambient temperature, land use and urban characteristics, combined with the measured elemental carbon concentrations, NOx (Brisbane) and NO2 (Barcelona). The trends and modes of the quantified weekday average daily cycles of ambient PNC exhibited significant differences between the two cities. PNC increases were observed during traffic rush hours in both cases. However, the mid-day peak was dominant in Brisbane schools and had the highest contribution to total PNC for both indoors and outdoors. In Barcelona, the contribution from traffic was highest for ambient PNC, while the mid-day peak had a slightly higher contribution for indoor concentrations. Analysis of the relationships between PNC and land use characteristics in Barcelona schools showed a moderate correlation with the percentage of road network area and an anti-correlation with the percentage of green area. No statistically significant correlations were found for Brisbane. Overall, despite many similarities between the two cities, school-based exposure patterns were different. The main source of ambient PNC at schools was shown to be traffic in Barcelona and mid-day new particle formation in Brisbane. The mid-day PNC peak in Brisbane could have been driven by the combined effect of background and meteorological conditions, as well as other local/distant sources. The results have implications for urban development

Monitoring of exposure to methylpentanes by diffusive sampling and urine analysis for alcoholic metabolites.

PubMed Central

Kawai, T; Mizunuma, K; Yasugi, T; Horiguchi, S; Iguchi, H; Mutti, A; Ghittori, S; Ikeda, M

1995-01-01

OBJECTIVES--To investigate the possibilities of personal ambient monitoring and biological monitoring for methylpentane isomers. METHODS--The performance of activated carbon cloth to absorb 2- and 3-methylpentane was studied by experimental vapour exposure followed by solvent extraction and gas chromatography (GC). Urine from workers and rats exposed to 2- and 3-methylpentane was analysed by GC with or without acid or enzymatic hydrolysis. RESULTS--Carbon cloth absorbed 2- and 3-methylpentane linearly to exposures up to eight hours and to 400 ppm, and was sensitive enough to detect a 15 minute peak of exposure. The two isomers were clearly separated from hexane on a DB-1 column. For analysis of the urine, enzymatic hydrolysis was superior to acid hydrolysis. Exposure of rats to methylpentane vapours showed that 2-methyl-2-pentanol and 3-methyl-2-pentanol were excreted in urine in proportion to the dose of 2-methylpentane and 3-methylpentane, respectively. 2-Methyl derivatives of 1-, 3-, and 4-propanol, 2-methylpentane-2,4-diol, and 3-methyl-2-pentanol were minor metabolites. Analysis of urine from the exposed workers showed that 2-methyl- and 3-methyl-2-pentanol are leading urinary metabolites after exposure to the corresponding methylpentane. CONCLUSIONS--Diffusive sampling is applicable to monitor 2- and 3-methylpentane vapours as is the case for hexane vapour. 2-Methyl-2-pentanol and 3-methyl-2-pentanol will be markers of occupational exposure to 2-methylpentane and 3-methylpentane, respectively. Also, 2-methylpentane-2,4-diol might be a marker of exposure to 2-methylpentane. PMID:8535496

Mediation analysis allowing for exposure-mediator interactions and causal interpretation: theoretical assumptions and implementation with SAS and SPSS macros.

PubMed

Valeri, Linda; Vanderweele, Tyler J

2013-06-01

Mediation analysis is a useful and widely employed approach to studies in the field of psychology and in the social and biomedical sciences. The contributions of this article are several-fold. First we seek to bring the developments in mediation analysis for nonlinear models within the counterfactual framework to the psychology audience in an accessible format and compare the sorts of inferences about mediation that are possible in the presence of exposure-mediator interaction when using a counterfactual versus the standard statistical approach. Second, the work by VanderWeele and Vansteelandt (2009, 2010) is extended here to allow for dichotomous mediators and count outcomes. Third, we provide SAS and SPSS macros to implement all of these mediation analysis techniques automatically, and we compare the types of inferences about mediation that are allowed by a variety of software macros. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Myelodysplastic Syndrome and Benzene Exposure Among Petroleum Workers: An International Pooled Analysis

PubMed Central

2012-01-01

Background Benzene at high concentrations is known to cause acute myeloid leukemia (AML), but its relationship with other lymphohematopoietic (LH) cancers remains uncertain, particularly at low concentrations. In this pooled analysis, we examined the risk of five LH cancers relative to lower levels of benzene exposure in petroleum workers. Methods We updated three nested case–control studies from Australia, Canada, and the United Kingdom with new incident LH cancers among petroleum distribution workers through December 31, 2006, and pooled 370 potential case subjects and 1587 matched LH cancer-free control subjects. Quantitative benzene exposure in parts per million (ppm) was blindly reconstructed using historical monitoring data, and exposure certainty was scored as high, medium, or low. Two hematopathologists assigned diagnoses and scored the certainty of diagnosis as high, medium, or low. Dose–response relationships were examined for five LH cancers, including the three most common leukemia cell-types (AML, chronic myeloid leukemia [CML], and chronic lymphoid leukemia [CLL]) and two myeloid tumors (myelodysplastic syndrome [MDS] and myeloproliferative disease [MPD]). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression, controlling for age, sex, and time period. Results Cumulative benzene exposure showed a monotonic dose–response relationship with MDS (highest vs lowest tertile, >2.93 vs ≤0.348 ppm-years, OR = 4.33, 95% CI = 1.31 to 14.3). For peak benezene exposures (>3 ppm), the risk of MDS was increased in high and medium certainty diagnoses (peak exposure vs no peak exposure, OR = 6.32, 95% CI = 1.32 to 30.2) and in workers having the highest exposure certainty (peak exposure vs no peak exposure, OR = 5.74, 95% CI = 1.05 to 31.2). There was little evidence of dose–response relationships for AML, CLL, CML, or MPD. Conclusions Relatively low-level exposure to benzene experienced by petroleum

Comparative analysis of the countermeasures taken to mitigate exposure of the public to radioiodine following the Chernobyl and Fukushima accidents: lessons from both accidents

PubMed Central

Uyba, Vladimir; Samoylov, Alexander; Shinkarev, Sergey

2018-01-01

Abstract In the case of a severe radiation accident at a nuclear power station, the most important radiation hazard for the public is internal exposure of the thyroid to radioiodine. The purposes of this paper were (i) to compare countermeasures conducted (following the Chernobyl and Fukushima accidents) aimed at mitigation of exposure to the thyroid for the public, (ii) to present comparative estimates of doses to the thyroid and (iii) to derive lessons from the two accidents. The scale and time of countermeasures applied in the early phase of the accidents (sheltering, evacuation, and intake of stable iodine to block the thyroid) and at a later time (control of 131I concentration in foodstuffs) have been described. After the Chernobyl accident, the estimation of the thyroid doses for the public was mainly based on direct thyroid measurements of ~400 000 residents carried out within the first 2 months. The highest estimates of thyroid doses to children reached 50 Gy. After the Fukushima accident, the estimation of thyroid doses was based on radioecological models due to a lack of direct thyroid measurements (only slightly more than 1000 residents were measured). The highest estimates of thyroid doses to children were a few hundred mGy. Following the Chernobyl accident, ingestion of 131I through cows’ milk was the dominant pathway. Following the Fukushima accident, it appears that inhalation of contaminated air was the dominant pathway. Some lessons learned following the Chernobyl and Fukushima accidents have been presented in this paper. PMID:29415268

Identification of the key molecules involved in chronic copper exposure-aggravated memory impairment in transgenic mice of Alzheimer's disease using proteomic analysis.

PubMed

Yu, Jun; Luo, Xiaobin; Xu, Hua; Ma, Quan; Yuan, Jianhui; Li, Xuling; Chang, Raymond Chuen-Chung; Qu, Zhongsen; Huang, Xinfeng; Zhuang, Zhixiong; Liu, Jianjun; Yang, Xifei

2015-01-01

Alzheimer's disease (AD) is the most common neurodegenerative disease characterized by a progressive impairment of cognitive functions including spatial learning and memory. Excess copper exposure accelerates the development of AD; however, the potential mechanisms by which copper exacerbates the symptoms of AD remain unknown. In this study, we explored the effects of chronic copper exposure on cognitive function by treating 6 month-old triple AD transgenic (3xTg-AD) mice with 250 ppm copper sulfate in drinking water for 6 months, and identified several potential key molecules involved in the effects of chronic copper exposure on memory by proteomic analysis. The behavioral test showed that chronic copper exposure aggravated memory impairment of 3xTg-AD mice. Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled with mass spectrometry revealed a total of 44 differentially expressed proteins (18 upregulated and 26 down-regulated) in hippocampus between the wild-type (WT) mice and non-exposed 3xTg-AD mice. A total of 40 differentially expressed proteins were revealed (20 upregulated and 20 down-regulated) in hippocampus between copper exposed and non-exposed 3xTg-AD mice. Among these differentially expressed proteins, complexin-1 and complexin-2, two memory associated proteins, were significantly decreased in hippocampus of 3xTg-AD mice compared with the WT mice. Furthermore, the expression of these two proteins was further down-regulated in 3xTg-AD mice when exposed to copper. The abnormal expression of complexin-1 and complexin-2 identified by proteomic analysis was verified by western blot analysis. Taken together, our data showed that chronic copper exposure accelerated memory impairment and altered the expression of proteins in hippocampus in 3xTg-AD mice. The functional analysis on the differentially expressed proteins suggested that complexin-1 and complexin-2 may be the key molecules involved in chronic copper exposure

Comparative Plasma Exposure of Albendazole after Administration of Rapidly Disintegrating Tablets in Dogs

PubMed Central

Castro, Silvina G.; Dib, Alicia; Suarez, Gonzalo; Allemandi, Daniel; Lanusse, Carlos; Sanchez Bruni, Sergio; Palma, Santiago D.

2013-01-01

The main objectives of this study were (a) to evaluate the in vitro performance of the rapid disintegration tablets as a way to improve the solid dispersions and (b) to study the in vivo pharmacokinetics of the albendazole modified formulation in dogs. Rapid disintegration of tablets seems to be a key factor for efficiency of solid dispersions with regard to improvement of the albendazole bioavailability. The in vivo assays performed on dogs showed a marked increase in drug plasma exposure when albendazole was given in solid dispersions incorporated into rapid disintegration tablets compared with conventional solid dosage form. PMID:24063016

Prolonged Exposure Therapy for Combat-Related Posttraumatic Stress Disorder: Comparing Outcomes for Veterans of Different Wars

PubMed Central

Yoder, Matthew; Tuerk, Peter W.; Price, Matthew; Grubaugh, Anouk L.; Strachan, Martha; Myrick, Hugh; Acierno, Ron

2012-01-01

There is significant support for exposure therapy as an effective treatment for posttraumatic stress disorder (PTSD) across a variety of populations, including veterans; however, there is little empirical information regarding how veterans of different war theaters respond to exposure therapy. Accordingly, questions remain regarding therapy effectiveness for treatment of PTSD for veterans of different eras. Such questions have important implications for the dissemination of evidence based treatments, treatment development, and policy. The current study compared treatment outcomes across 112 veterans of the Vietnam War, the first Persian Gulf War, and the wars in Afghanistan and Iraq. All subjects were diagnosed with PTSD and enrolled in Prolonged Exposure (PE) treatment. Veterans from all three groups showed significant improvement in PTSD symptoms, with veterans from Vietnam and Afghanistan/Iraq responding similarly to treatment. Persian Gulf veterans did not respond to treatment at the same rate or to the same degree as veterans from the other two eras. Questions and issues regarding the effectiveness of evidence based treatment for veterans from different eras are discussed. PMID:22449084

Prolonged exposure therapy for combat-related posttraumatic stress disorder: comparing outcomes for veterans of different wars.

PubMed

Yoder, Matthew; Tuerk, Peter W; Price, Matthew; Grubaugh, Anouk L; Strachan, Martha; Myrick, Hugh; Acierno, Ron

2012-02-01

There is significant support for exposure therapy as an effective treatment for posttraumatic stress disorder (PTSD) across a variety of populations, including veterans; however, there is little empirical information regarding how veterans of different war theaters respond to exposure therapy. Accordingly, questions remain regarding therapy effectiveness for treatment of PTSD for veterans of different eras. Such questions have important implications for the dissemination of evidence based treatments, treatment development, and policy. The current study compared treatment outcomes across 112 veterans of the Vietnam War, the first Persian Gulf War, and the wars in Afghanistan and Iraq. All subjects were diagnosed with PTSD and enrolled in prolonged exposure (PE) treatment. Veterans from all three groups showed significant improvement in PTSD symptoms, with veterans from Vietnam and Afghanistan/Iraq responding similarly to treatment. Persian Gulf veterans did not respond to treatment at the same rate or to the same degree as veterans from the other two eras. Questions and issues regarding the effectiveness of evidence based treatment for veterans from different eras are discussed.

Comparative risk assessment of carcinogens in alcoholic beverages using the margin of exposure approach.

PubMed

Lachenmeier, Dirk W; Przybylski, Maria C; Rehm, Jürgen

2012-09-15

Alcoholic beverages have been classified as carcinogenic to humans. As alcoholic beverages are multicomponent mixtures containing several carcinogenic compounds, a quantitative approach is necessary to compare the risks. Fifteen known and suspected human carcinogens (acetaldehyde, acrylamide, aflatoxins, arsenic, benzene, cadmium, ethanol, ethyl carbamate, formaldehyde, furan, lead, 4-methylimidazole, N-nitrosodimethylamine, ochratoxin A and safrole) occurring in alcoholic beverages were identified based on monograph reviews by the International Agency for Research on Cancer. The margin of exposure (MOE) approach was used for comparative risk assessment. MOE compares a toxicological threshold with the exposure. MOEs above 10,000 are judged as low priority for risk management action. MOEs were calculated for different drinking scenarios (low risk and heavy drinking) and different levels of contamination for four beverage groups (beer, wine, spirits and unrecorded alcohol). The lowest MOEs were found for ethanol (3.1 for low risk and 0.8 for heavy drinking). Inorganic lead and arsenic have average MOEs between 10 and 300, followed by acetaldehyde, cadmium and ethyl carbamate between 1,000 and 10,000. All other compounds had average MOEs above 10,000 independent of beverage type. Ethanol was identified as the most important carcinogen in alcoholic beverages, with clear dose response. Some other compounds (lead, arsenic, ethyl carbamate, acetaldehyde) may pose risks below thresholds normally tolerated for food contaminants, but from a cost-effectiveness point of view, the focus should be on reducing alcohol consumption in general rather than on mitigative measures for some contaminants that contribute only to a limited extent (if at all) to the total health risk. Copyright © 2012 UICC.

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

PubMed

Kurth, Laura; Doney, Brent; Weinmann, Sheila

2017-03-01

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

Detergent protease exposure and respiratory disease: case-referent analysis of a retrospective cohort.

PubMed

Brant, A; Upchurch, S; van Tongeren, M; Zekveld, C; Helm, J; Barnes, F; Newman Taylor, A J; Cullinan, P

2009-11-01

To examine the relationship between protease exposure and respiratory disease in a cohort of detergent enzyme manufacturers. Case-referent analysis of a cohort of employees working in a European detergent factory between 1989 and 2002. Cases with new lower or upper respiratory disease were ascertained by examination of occupational health records and matched to referents on date of first employment. Personal exposures to airborne detergent protease were estimated, using a job exposure matrix, from >12,000 measurements taken in the factory during the period of study. We found clear, monotonic relationships between estimated protease exposure and both lower and upper respiratory disease. After control for age, sex and smoking, the odds ratio of lower respiratory disease was significantly elevated (1.98, 95% CI 1.04 to 3.79) in those employees working in jobs in the highest quartile of protease exposure (geometric mean 7.9 ng x m(-3)). For employees with upper respiratory disease, the risk was significantly elevated at a lower level of estimated protease exposure (geometric mean 2.3 ng x m(-3)). These findings provide strong evidence of an association between detergent enzyme exposure and the development of respiratory disease in an occupational setting. Using the routinely collected information on specific sensitisation and the close attention to workplace exposures that are characteristic of this industry, it should be possible to derive meaningful occupational exposure standards for most detergent enzymes.

Virtual reality compared with in vivo exposure in the treatment of social anxiety disorder: a three-arm randomised controlled trial.

PubMed

Bouchard, Stéphane; Dumoulin, Stéphanie; Robillard, Geneviève; Guitard, Tanya; Klinger, Évelyne; Forget, Hélène; Loranger, Claudie; Roucaut, François Xavier

2017-04-01

Background People with social anxiety disorder (SAD) fear social interactions and may be reluctant to seek treatments involving exposure to social situations. Social exposure conducted in virtual reality (VR), embedded in individual cognitive-behavioural therapy (CBT), could be an answer. Aims To show that conducting VR exposure in CBT for SAD is effective and is more practical for therapists than conducting exposure in vivo Method Participants were randomly assigned to either VR exposure ( n = 17), in vivo exposure ( n = 22) or waiting list ( n = 20). Participants in the active arms received individual CBT for 14 weekly sessions and outcome was assessed with questionnaires and a behaviour avoidance test. (Trial registration number ISRCTN99747069) Results Improvements were found on the primary (Liebowitz Social Anxiety Scale) and all five secondary outcome measures in both CBT groups compared with the waiting list. Conducting exposure in VR was more effective at post-treatment than in vivo on the primary outcome measure and on one secondary measure. Improvements were maintained at the 6-month follow-up. VR was significantly more practical for therapists than in vivo exposure. Conclusions Using VR can be advantageous over standard CBT as a potential solution for treatment avoidance and as an efficient, cost-effective and practical medium of exposure. © The Royal College of Psychiatrists 2017.

Comparing Results from Constant Comparative and Computer Software Methods: A Reflection about Qualitative Data Analysis

ERIC Educational Resources Information Center

Putten, Jim Vander; Nolen, Amanda L.

2010-01-01

This study compared qualitative research results obtained by manual constant comparative analysis with results obtained by computer software analysis of the same data. An investigated about issues of trustworthiness and accuracy ensued. Results indicated that the inductive constant comparative data analysis generated 51 codes and two coding levels…

TISSUE CONCENTRATION OF PCBS IN ANIMAL EXPERIMENTS AS COMPARED WITH THOSE IN HUMANS WITH BACKGROUND-LEVEL EXPOSURE

EPA Science Inventory

TISSUE CONCENTRATION OF PCBS IN ANIMAL EXPERIMENTS AS COMPARED WITH THOSE IN HUMANS WITH BACKGROUND-LEVEL EXPOSURE. M J DeVito1 and M P Longnecker2. 1NHEERL, ORD, USEPA; Research Triangle Park, NC, USA; 2Epidemiology
Branch, NIEHS, Research Triangle Park, NC, USA.

To ...

Cadmium exposure and risk of lung cancer: a meta-analysis of cohort and case-control studies among general and occupational populations.

PubMed

Chen, Cheng; Xun, Pengcheng; Nishijo, Muneko; He, Ka

2016-09-01

The association between cadmium exposure and risk of lung cancer is still unclear. We quantitatively reviewed the observational studies that investigated the association between cadmium exposure and lung cancer risk in both general and occupational populations published through April 2015. The final data set is comprised of three cohort studies in the general population totaling 22,551 participants (354 events) with a mean follow-up of 15 years, five occupational cohort studies including 4205 individuals (180 events) with an average follow-up of 31 years, and three occupational case-control studies including 4740 cases and 6268 controls. Comparing the highest to the lowest category of cadmium exposure, the weighted relative risk and 95% confidence interval of lung cancer in the general population was 1.42 (95% CI (0.91, 2.23)); the weighted risk estimates (95% CIs) of lung cancer in three occupational cohort studies and three case-control studies were 0.68 (95% CI (0.33, 1.41)) and 1.61 (95% CI (0.94, 2.75)), respectively. No linear association was found. When comparing participants exposed to cadmium with non-exposed based on available data, the association became statistically significant. According to findings from this meta-analysis, the possibility that cadmium exposure may increase risk of lung cancer cannot be completely ruled out in either general or occupational population.

Vehicle Exposure and Spinal Musculature Fatigue in Military Warfighters: A Meta-Analysis.

PubMed

Kollock, Roger O; Games, Kenneth E; Wilson, Alan E; Sefton, JoEllen M

2016-11-01

 Spinal musculature fatigue from vehicle exposure may place warfighters at risk for spinal injuries and pain. Research on the relationship between vehicle exposure and spinal musculature fatigue is conflicting. A better understanding of the effect of military duty on musculoskeletal function is needed before sports medicine teams can develop injury-prevention programs.  To determine if the literature supports a definite effect of vehicle exposure on spinal musculature fatigue.  We searched the MEDLINE, Military & Government Collection (EBSCO), National Institute for Occupational Safety and Health Technical Information Center, PubMed, and Web of Science databases for articles published between January 1990 and September 2015.  To be included, a study required a clear sampling method, preexposure and postexposure assessments of fatigue, a defined objective measurement of fatigue, a defined exposure time, and a study goal of exposing participants to forces related to vehicle exposure.  Sample size, mean preexposure and postexposure measures of fatigue, vehicle type, and exposure time.  Six studies met the inclusion criteria. We used the Scottish Intercollegiate Guidelines Network algorithm to determine the appropriate tool for quality appraisal of each article. Unweighted random-effects model meta-analyses were conducted, and a natural log response ratio was used as the effect metric. The overall meta-analysis demonstrated that vehicle exposure increased fatigue of the spinal musculature (P = .03; natural log response ratio = -0.22, 95% confidence interval = -0.42, -0.02). Using the spinal region as a moderator, we observed that vehicle ride exposure significantly increased fatigue at the lumbar musculature (P = .02; natural log response ratio = -0.27, 95% confidence interval = -0.50, -0.04) but not at the cervical or thoracic region.  Vehicle exposure increased fatigue at the lumbar region.

Vehicle Exposure and Spinal Musculature Fatigue in Military Warfighters: A Meta-Analysis

PubMed Central

Kollock, Roger O.; Games, Kenneth E.; Wilson, Alan E.; Sefton, JoEllen M.

2016-01-01

Context: Spinal musculature fatigue from vehicle exposure may place warfighters at risk for spinal injuries and pain. Research on the relationship between vehicle exposure and spinal musculature fatigue is conflicting. A better understanding of the effect of military duty on musculoskeletal function is needed before sports medicine teams can develop injury-prevention programs. Objective: To determine if the literature supports a definite effect of vehicle exposure on spinal musculature fatigue. Data Sources: We searched the MEDLINE, Military & Government Collection (EBSCO), National Institute for Occupational Safety and Health Technical Information Center, PubMed, and Web of Science databases for articles published between January 1990 and September 2015. Study Selection: To be included, a study required a clear sampling method, preexposure and postexposure assessments of fatigue, a defined objective measurement of fatigue, a defined exposure time, and a study goal of exposing participants to forces related to vehicle exposure. Data Extraction: Sample size, mean preexposure and postexposure measures of fatigue, vehicle type, and exposure time. Data Synthesis: Six studies met the inclusion criteria. We used the Scottish Intercollegiate Guidelines Network algorithm to determine the appropriate tool for quality appraisal of each article. Unweighted random-effects model meta-analyses were conducted, and a natural log response ratio was used as the effect metric. The overall meta-analysis demonstrated that vehicle exposure increased fatigue of the spinal musculature (P = .03; natural log response ratio = −0.22, 95% confidence interval = −0.42, −0.02). Using the spinal region as a moderator, we observed that vehicle ride exposure significantly increased fatigue at the lumbar musculature (P = .02; natural log response ratio = −0.27, 95% confidence interval = −0.50, −0.04) but not at the cervical or thoracic region. Conclusions: Vehicle exposure increased

A modular Human Exposure Model (HEM) framework to ...

EPA Pesticide Factsheets

Life Cycle Impact Analysis (LCIA) has proven to be a valuable tool for systematically comparing processes and products, and has been proposed for use in Chemical Alternatives Analysis (CAA). The exposure assessment portion of the human health impact scores of LCIA has historically focused on far-field sources (environmentally mediated exposures) while research has shown that use related exposures, (near-field exposures) typically dominate population exposure. Characterizing the human health impacts of chemicals in consumer products over the life cycle of these products requires an evaluation of both near-field as well far-field sources. Assessing the impacts of the near-field exposures requires bridging the scientific and technical gaps that currently prevent the harmonious use of the best available methods and tools from the fields of LCIA and human health exposure and risk assessment. The U.S. EPA’s Chemical Safety and Sustainability LC-HEM project is developing the Human Exposure Model (HEM) to assess near-field exposures to chemicals that occur to various populations over the life cycle of a commercial product. The HEM will be a publically available, web-based, modular system which will allow for the evaluation of chemical/product impacts in a LCIA framework to support CAA. We present here an overview of the framework for the modular HEM system. The framework includes a data flow diagram of in-progress and future planned modules, the definition of each mod

Efficacy of hair analysis for monitoring exposure to uranium: a mini-review.

PubMed

Joksić, Agnes Šömen; Katz, Sidney A

2014-01-01

In spite of the ease with which samples may be collected and the stability of the samples after collection, the use of hair mineral analysis for monitoring environmental exposures and evaluating heavy metal poisonings has remained controversial since its initial applications for these purposes in the early 1950s. Among the major arguments against using hair mineral analysis in general were the absence of biokinetic models and/or metabolic data that adequately described the incorporation of trace elements into the hair, the absence of correlations between the concentrations of trace elements in the hair and their concentrations in other tissues, the inability to distinguish between trace elements that were deposited in the hair endogenously and those that were deposited on the hair exogenously, the absence of reliable reference ranges for interpreting the results of hair mineral analysis and a lack of standard procedures for the collecting, preparing and analyzing the hair samples. The developments of the past two decades addressing these objections are reviewed here, and arguments supporting the use of hair analysis for monitoring environmental and/or occupational exposures to uranium are made on the basis of the information presented in this review.

Comparative pulmonary toxicological assessment of oil combustion particles following inhalation or instillation exposure.

PubMed

Costa, Daniel L; Lehmann, James R; Winsett, Darrell; Richards, Judy; Ledbetter, Allen D; Dreher, Kevin L

2006-05-01

Controversy persists regarding the validity of intratracheal instillation (IT) of particulate matter (PM) as a surrogate for inhalation exposure (IH) in rodents. Concerns center on dose, dose-rate, and distribution of material within the lung. Acute toxicity of a residual oil fly ash (ROFA) administered by IH was compared to those effects of a single IT bolus at an IH-equivalent dose. Male Sprague Dawley rats (60 days old) were exposed by nose-only IH to approximately 12 mg/m3 for 6 h. Inter-lobar dose distribution of ROFA, dissected immediately post exposure, was assayed by neutron activation. Vanadium and nickel were used as ROFA markers. IT administration of the IH-equivalent dose (110 microg) showed similar (<15%) interlobular distribution, with the exception of the inferior lobe dose (IT>IH approximately 25%). Evaluation of airway hyperreactivity (AHR), bronchoalveolar lavage fluid (BALF) constituents, and histopathology was conducted at 24, 48, and 96 h post exposure. AHR in the IH group was minimally (p > 0.05) affected by treatment, but was significantly increased ( approximately 40%) at both 24 and 48 h post IT. Inflammation in both groups, as measured by alterations in BALF protein, lactate dehydrogenase and neutrophils, was virtually identical at all time points. Alveolitis and bronchial inflammation/epithelial hypertrophy were prominent 24 h following IT, but not apparent after IH. Conversely, alveolar hemorrhage, congestion, and airway exudate were pronounced at 48 h post-IH but not remarkable in the IT group. Thus, IT-ROFA mimicked IH in terms of lobar distribution and injury biomarkers over 96 h, while morphological alterations and AHR appeared to be more dependent on the method of administration.

FAULT TREE ANALYSIS FOR EXPOSURE TO REFRIGERANTS USED FOR AUTOMOTIVE AIR CONDITIONING IN THE U.S.

EPA Science Inventory

A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servic...

Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers.

PubMed

Chang, Ellen T; Delzell, Elizabeth

2016-01-01

This systematic review and meta-analysis rigorously examines the relationship between glyphosate exposure and risk of lymphohematopoietic cancer (LHC) including NHL, Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia. Meta-relative risks (meta-RRs) were positive and marginally statistically significant for the association between any versus no use of glyphosate and risk of NHL (meta-RR = 1.3, 95% confidence interval (CI) = 1.0-1.6, based on six studies) and MM (meta-RR = 1.4, 95% CI = 1.0-1.9; four studies). Associations were statistically null for HL (meta-RR = 1.1, 95% CI = 0.7-1.6; two studies), leukemia (meta-RR = 1.0, 95% CI = 0.6-1.5; three studies), and NHL subtypes except B-cell lymphoma (two studies each). Bias and confounding may account for observed associations. Meta-analysis is constrained by few studies and a crude exposure metric, while the overall body of literature is methodologically limited and findings are not strong or consistent. Thus, a causal relationship has not been established between glyphosate exposure and risk of any type of LHC.

Caregiver talk to young Spanish-English bilinguals: Comparing direct observation and parent-report measures of dual-language exposure

PubMed Central

Marchman, Virginia A.; Martínez, Lucía Z.; Hurtado, Nereyda; Grüter, Theres; Fernald, Anne

2016-01-01

In research on language development by bilingual children, the early language environment is commonly characterized in terms of the relative amount of exposure a child gets to each language based on parent report. Little is known about how absolute measures of child-directed speech in two languages relate to language growth. In this study of 3-year-old Spanish-English bilinguals (n = 18), traditional parent-report estimates of exposure were compared to measures of the number of Spanish and English words children heard during naturalistic audio recordings. While the two estimates were moderately correlated, observed numbers of child-directed words were more consistently predictive of children's processing speed and standardized test performance, even when controlling for reported proportion of exposure. These findings highlight the importance of caregiver engagement in bilingual children's language outcomes in both of the languages they are learning. PMID:27197746

Lipid Adjustment for Chemical Exposures: Accounting for Concomitant Variables

PubMed Central

Li, Daniel; Longnecker, Matthew P.; Dunson, David B.

2013-01-01

Background Some environmental chemical exposures are lipophilic and need to be adjusted by serum lipid levels before data analyses. There are currently various strategies that attempt to account for this problem, but all have their drawbacks. To address such concerns, we propose a new method that uses Box-Cox transformations and a simple Bayesian hierarchical model to adjust for lipophilic chemical exposures. Methods We compared our Box-Cox method to existing methods. We ran simulation studies in which increasing levels of lipid-adjusted chemical exposure did and did not increase the odds of having a disease, and we looked at both single-exposure and multiple-exposures cases. We also analyzed an epidemiology dataset that examined the effects of various chemical exposures on the risk of birth defects. Results Compared with existing methods, our Box-Cox method produced unbiased estimates, good coverage, similar power, and lower type-I error rates. This was the case in both single- and multiple-exposure simulation studies. Results from analysis of the birth-defect data differed from results using existing methods. Conclusion Our Box-Cox method is a novel and intuitive way to account for the lipophilic nature of certain chemical exposures. It addresses some of the problems with existing methods, is easily extendable to multiple exposures, and can be used in any analyses that involve concomitant variables. PMID:24051893

Effect of Exposure Type and Timing of Injuries in Division I College Football: A 4-year Single Program Analysis.

PubMed

Krill, Michael K; Borchers, James R; Hoffman, Joshua T; Tatarski, Rachel L; Hewett, Timothy E

2017-02-01

Football players compete with a high risk of injury due to the sport. With the recent efforts to improve safety, the National Collegiate Athletic Association (NCAA) established new terminology to clearly define exposure types and reduce the number of high contact exposures. To compare football injury rates (IR) with a focus on game versus practice, time in season of injury, mechanism of injury and utilizing recent exposure types defined by the NCAA (live contact, full-pads and non-contact). Licensed medical professionals monitored a college football program regular season from 2012-2015. Each injury was classified by timing of the injury, mechanism of injury, and whether it occurred in game or practice. Player attendance and type of exposure (non-contact, full-pad or live contact, which involves live tackling to the ground and/or full-speed blocking and can occur in full-pad or half-pad ('shell') equipment) was documented. IR were calculated per 1000 athlete-exposures (AE). Mid-exact P tests compared rates between variables. The game IR was over three times as high as the practice IR (p < .001). Live contact exposures had the greatest IR of 5.702/1000 AE and were seven times more likely to produce an injury compared to non-contact exposures (p < .001); whereas, live contact exposures were about two times more likely to produce an injury compared to full-pad exposures (p = .004). The majority of injuries observed occurred from a contact mechanism (IR: 2.508/1000 AE). The highest IR during the fall football season occurred in the pre-season at 5.769/1000 AE. Overall IR observed in this cohort were lower than prior studies published before recent NCAA rule changes and guideline implementation to improve athlete safety. Athletes in this cohort were at significantly increased risk of injury from live contact exposures.

Prenatal exposure to bisphenol A and hyperactivity in children: a systematic review and meta-analysis.

PubMed

Rochester, Johanna R; Bolden, Ashley L; Kwiatkowski, Carol F

2018-05-01

Attention-deficit hyperactivity disorder (ADHD) has increased in prevalence in the past decade. Studies attempting to identify a specific genetic component have not been able to account for much of the heritability of ADHD, indicating there may be gene-environment interactions underlying the disorder, including early exposure to environmental chemicals. Based on several relevant studies, we chose to examine bisphenol A (BPA) as a possible contributor to ADHD in humans. BPA is a widespread environmental chemical that has been shown to disrupt neurodevelopment in rodents and humans. Using the Office of Health Assessment and Translation (OHAT) framework, a systematic review and meta-analysis was designed to determine the relationship between early life exposure to BPA and hyperactivity, a key diagnostic criterion of ADHD. Searches of PubMed, Web of Science, and Toxline were completed for all literature to January 1, 2017. For inclusion, the studies had to publish original data, be in the English language, include a measure of BPA exposure, and assess if BPA exposure affected hyperactive behaviors in mice, rats or humans. Exposure to BPA had to occur at <3 months of age for humans, up to postnatal day 35 for rats and up to postnatal day 40 for mice. Exposure could occur either gestationally (via maternal exposure) or directly to the offspring. Studies were evaluated using the OHAT risk of bias tool. The effects in humans were assessed qualitatively. For rodents exposed to 20 μg/kg/day BPA, we evaluated the study findings in a random effects meta-analytical model. A review of the literature identified 29 rodent and 3 human studies. A random effects meta-analysis showed significantly increased hyperactivity in male rodents. In humans, early BPA exposure was associated with hyperactivity in boys and girls. We concluded that early life BPA exposure is a presumed human hazard for the development of hyperactivity. Possible limitations of this systematic review include

Intimate partner violence screening and the comparative effects of screening mode on disclosure of sensitive health behaviours and exposures in clinical settings.

PubMed

Frazier, T; Yount, K M

2017-02-01

Detecting sensitive health information in clinical settings is of scientific and practical importance. The purpose of this study was to determine whether mode of screening influenced disclosure of intimate partner violence (IPV) in patterns similar to other forms of sensitive information. This cross sectional study was designed to compare effects of face-to-face vs computer self-assessment for sensitive health information on disclosure rates. Multivariate logistic regression was used for the analysis. Data were collected in 2012 from 639 eligible African American consenting women receiving services in women, infants and children (WIC) clinics. Women were randomized to complete assessments of sensitive exposures via computer-assisted self-interview (CASI) or face-to-face interview (FTFI). Those with complete information were included in the analysis (n = 616). Of 39 sensitive health exposures, reporting was higher for FTFI than CASI for exposure to IPV (7 of 7 outcomes), tobacco use (2 of 3 outcomes) and reproductive health care (2 of 3 outcomes). For example, face-to-face improved disclosure of IPV in the last year (adjusted odds ratios [aOR] = 2.27; 95% CI = 1.60-3.21) and any drug, tobacco or alcohol in the last week (aOR = 1.39; 95% CI = 1.00-1.93). Trained personnel may enhance disclosure above computer-based assessments for IPV for African American women receiving public assistance through The Special Supplemental Nutrition Program for Women, Infants and Children (WIC) Propensities to disclose sexual health behaviour and drug use by CASI may not apply to IPV in this population. The context and personal motivations influence women's decision to disclose IPV. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

A comparative analysis of modeled and monitored ambient hazardous air pollutants in Texas: a novel approach using concordance correlation.

PubMed

Lupo, Philip J; Symanski, Elaine

2009-11-01

Often, in studies evaluating the health effects of hazardous air pollutants (HAPs), researchers rely on ambient air levels to estimate exposure. Two potential data sources are modeled estimates from the U.S. Environmental Protection Agency (EPA) Assessment System for Population Exposure Nationwide (ASPEN) and ambient air pollutant measurements from monitoring networks. The goal was to conduct comparisons of modeled and monitored estimates of HAP levels in the state of Texas using traditional approaches and a previously unexploited method, concordance correlation analysis, to better inform decisions regarding agreement. Census tract-level ASPEN estimates and monitoring data for all HAPs throughout Texas, available from the EPA Air Quality System, were obtained for 1990, 1996, and 1999. Monitoring sites were mapped to census tracts using U.S. Census data. Exclusions were applied to restrict the monitored data to measurements collected using a common sampling strategy with minimal missing values over time. Comparisons were made for 28 HAPs in 38 census tracts located primarily in urban areas throughout Texas. For each pollutant and by year of assessment, modeled and monitored air pollutant annual levels were compared using standard methods (i.e., ratios of model-to-monitor annual levels). Concordance correlation analysis was also used, which assesses linearity and agreement while providing a formal method of statistical inference. Forty-eight percent of the median model-to-monitor values fell between 0.5 and 2, whereas only 17% of concordance correlation coefficients were significant and greater than 0.5. On the basis of concordance correlation analysis, the findings indicate there is poorer agreement when compared with the previously applied ad hoc methods to assess comparability between modeled and monitored levels of ambient HAPs.

Comparative pharmacokinetic study of the role of gender and developmental differences in occupational and environmental exposure to benzene. Master's thesis

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

Brown, E.A.

The purpose of this study is two-fold. First, it shows that physiological differences between men and women result in gender-specific exposures with respect to benzene. Second, it assesses the potential for a lactating woman's occupational and personal benzene exposure to impact a nursing infant's exposure, highlighting the possibility of subjecting an infant to the effects of industrial chemicals via breast feeding. This study employs physiologically based pharmacokinetic (PBPK) modeling to investigate the influence of physiological parameters and to evaluate the ability of inhaled benzene to transfer from mother to infant through breastmilk. The models are run through scenarios that simulatemore » occupational, smoking, and background exposures. The gender comparison is facilitated by a sensitivity analysis. The blood/air partition coefficient and maximum velocity of metabolism were found to substantially impact model output. These values were both higher in women and caused an increase in the percentage of benzene metabolized in all of the exposure scenarios. The study of lactating women and infants is essentially theoretical. There is evidence that over 65% of an infant's benzene exposure can be attributed to contaminated breastmilk. A large portion of the ingested exposure can be eliminated by adjusting the mother's working or nursing schedule. Benzene, Physiologically based pharmacokinetics, PBPK.« less

Occupational exposure and risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis.

PubMed

Alif, Sheikh M; Dharmage, Shyamali C; Bowatte, Gayan; Karahalios, Amalia; Benke, Geza; Dennekamp, Martine; Mehta, Amar J; Miedinger, David; Künzli, Nino; Probst-Hensch, Nicole; Matheson, Melanie C

2016-08-01

Due to contradictory literature we have performed a systematic review and meta-analyse of population-based studies that have used Job Exposure Matrices to assess occupational exposure and risk of Chronic Obstructive Pulmonary Disease (COPD). Two researchers independently searched databases for published articles using predefined inclusion criteria. Study quality was assessed, and results pooled for COPD and chronic bronchitis for exposure to biological dust, mineral dust, and gases/fumes using a fixed and random effect model. Five studies met predetermined inclusion criteria. The meta-analysis showed low exposure to mineral dust, and high exposure to gases/fumes were associated with an increased risk of COPD. We also found significantly increased the risk of chronic bronchitis for low and high exposure to biological dust and mineral dust. Expert commentary: The relationship between occupational exposure assessed by the JEM and the risk of COPD and chronic bronchitis shows significant association with occupational exposure. However, the heterogeneity of the meta-analyses suggests more wide population-based studies with older age groups and longitudinal phenotype assessment of COPD to clarify the role of occupational exposure to COPD risk.

1H NMR-Based Metabolomic Analysis of Sub-Lethal Perfluorooctane Sulfonate Exposure to the Earthworm, Eisenia fetida, in Soil

PubMed Central

Lankadurai, Brian P.; Furdui, Vasile I.; Reiner, Eric J.; Simpson, André J.; Simpson, Myrna J.

2013-01-01

1H NMR-based metabolomics was used to measure the response of Eisenia fetida earthworms after exposure to sub-lethal concentrations of perfluorooctane sulfonate (PFOS) in soil. Earthworms were exposed to a range of PFOS concentrations (five, 10, 25, 50, 100 or 150 mg/kg) for two, seven and fourteen days. Earthworm tissues were extracted and analyzed by 1H NMR. Multivariate statistical analysis of the metabolic response of E. fetida to PFOS exposure identified time-dependent responses that were comprised of two separate modes of action: a non-polar narcosis type mechanism after two days of exposure and increased fatty acid oxidation after seven and fourteen days of exposure. Univariate statistical analysis revealed that 2-hexyl-5-ethyl-3-furansulfonate (HEFS), betaine, leucine, arginine, glutamate, maltose and ATP are potential indicators of PFOS exposure, as the concentrations of these metabolites fluctuated significantly. Overall, NMR-based metabolomic analysis suggests elevated fatty acid oxidation, disruption in energy metabolism and biological membrane structure and a possible interruption of ATP synthesis. These conclusions obtained from analysis of the metabolic profile in response to sub-lethal PFOS exposure indicates that NMR-based metabolomics is an excellent discovery tool when the mode of action (MOA) of contaminants is not clearly defined. PMID:24958147

[Paternal exposure to occupational electromagnetic radiation and sex ratio of the offspring: a meta-analysis].

PubMed

Tong, Shu-Hui; Liu, Yi-Ting; Liu, Yang

2013-02-01

To investigate the association between paternal exposure to occupational electromagnetic radiation and the sex ratio of the offspring. We searched various databases, including PubMed, Embase, Cochrane Library, OVID, Bioscience Information Service (BIOSIS), China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals and Wanfang Database, for the literature relevant to the association of paternal exposure to occupational electromagnetic radiation with the sex ratio of the offspring. We conducted a meta-analysis on their correlation using Stata 11.0. There was no statistically significant difference in the sex ratio between the offspring with paternal exposure to occupational electromagnetic radiation and those without (pooled OR = 1.00 [95% CI: 0.95 -1.05], P = 0.875). Subgroup analysis of both case-control and cohort studies revealed no significant difference (pooled OR = 1.03 [95% CI: 0.99 -1.08], P = 0.104 and pooled OR = 0.98 [95% CI: 0.99 -1.08], P = 0.186, respectively). Paternal exposure to occupational electromagnetic radiation is not correlated with the sex ratio of the offspring.

Lung cancer mortality among European rock/slag wool workers: exposure-response analysis.

PubMed

Consonni, D; Boffetta, P; Andersen, A; Chang-Claude, J; Cherrie, J W; Ferro, G; Frentzel-Beyme, R; Hansen, J; Olsen, J; Plato, N; Westerholm, P; Saracci, R

1998-08-01

The purpose was to analyze the relationship between semi-quantitative indices of exposure to manmade vitreous fibers and lung cancer mortality among European rock/slag wool (RSW) workers. The study population comprised 9,603 male workers employed in RSW production in seven factories in Denmark, Norway, Sweden, and Germany, followed up for mortality as of 1990-91. Estimates of past exposure to respirable fibers were used to calculate cumulative exposure with a 15-year lag and maximum annual exposure based on employment history up to 1977. Rate ratios were estimated via multivariate Poisson regression, adjusting for country, age, calendar year, time since first employment, and employment status. A total of 159 lung cancer deaths were included in the analysis of which 97 among workers with more than one year of employment. We found nonstatistically significant trends in lung cancer risk according to cumulative exposure. Relative risks (RR) in the four quartiles were 1.0 (reference), 1.3 (95 percent confidence interval [CI] = 0.8-2.4), 1.2 (CI = 0.7-2.1), and 1.5 (CI = 0.7-3.0, P test for trend = 0.4). When workers with less than one year of employment were excluded, there was no increased risk; the RRs in the four quartiles were 1.0, 0.9 (CI = 0.4-2.0), 0.8 (CI = 0.3-1.9), and 1.0 (CI = 0.4-2.7). No trend was present according to maximum annual exposure. The results were not consistent among countries. We found a positive association between exposure to respirable fibers and lung cancer mortality. However, the lack of statistical significance, the dependence of the results on inclusion of short-term workers, the lack of consistency among countries, and the possible correlation between exposure to respirable fibers and to other agents reduce the weight of such evidence.

Mapping of radio frequency electromagnetic field exposure levels in outdoor environment and comparing with reference levels for general public health.

PubMed

Cansiz, Mustafa; Abbasov, Teymuraz; Kurt, M Bahattin; Celik, A Recai

2018-03-01

In this study, radio frequency electromagnetic field exposure levels were measured on the main streets in the city center of Diyarbakır, Turkey. Measured electric field levels were plotted on satellite imagery of Diyarbakır and were compared with exposure guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Exposure measurements were performed in dense urban, urban and suburban areas each day for 7 consecutive days. The measurement system consisted of high precision and portable spectrum analyzer, three-axis electric field antenna, connection cable and a laptop which was used to record the measurement samples as a data logger. The highest exposure levels were detected for two places, which are called Diclekent and Batıkent. It was observed that the highest instantaneous electric field strength value for Batıkent was 7.18 V/m and for Diclekent was 5.81 V/m. It was statistically determined that the main contributor band to the total exposure levels was Universal Mobile Telecommunications System band. Finally, it was concluded that all measured exposure levels were lower than the reference levels recommended by ICNIRP for general public health.

SCALING THE PHYSIOLOGICAL EFFECTS OF EXPOSURE TO RADIOFREQUENCY ELECTROMAGNETIC RADIATION: CONSEQUENCES OF BODY SIZE

EPA Science Inventory

The authors have demonstrated that a comparative analysis of the physiological effects of exposure of laboratory mammals to radiofrequency electromagnetic radiation (RFR) may be useful in predicting exposure thresholds for humans if the effect is assumed to be due only to heating...

Bivariate Left-Censored Bayesian Model for Predicting Exposure: Preliminary Analysis of Worker Exposure during the Deepwater Horizon Oil Spill.

PubMed

Groth, Caroline; Banerjee, Sudipto; Ramachandran, Gurumurthy; Stenzel, Mark R; Sandler, Dale P; Blair, Aaron; Engel, Lawrence S; Kwok, Richard K; Stewart, Patricia A

2017-01-01

In April 2010, the Deepwater Horizon oil rig caught fire and exploded, releasing almost 5 million barrels of oil into the Gulf of Mexico over the ensuing 3 months. Thousands of oil spill workers participated in the spill response and clean-up efforts. The GuLF STUDY being conducted by the National Institute of Environmental Health Sciences is an epidemiological study to investigate potential adverse health effects among these oil spill clean-up workers. Many volatile chemicals were released from the oil into the air, including total hydrocarbons (THC), which is a composite of the volatile components of oil including benzene, toluene, ethylbenzene, xylene, and hexane (BTEXH). Our goal is to estimate exposure levels to these toxic chemicals for groups of oil spill workers in the study (hereafter called exposure groups, EGs) with likely comparable exposure distributions. A large number of air measurements were collected, but many EGs are characterized by datasets with a large percentage of censored measurements (below the analytic methods' limits of detection) and/or a limited number of measurements. We use THC for which there was less censoring to develop predictive linear models for specific BTEXH air exposures with higher degrees of censoring. We present a novel Bayesian hierarchical linear model that allows us to predict, for different EGs simultaneously, exposure levels of a second chemical while accounting for censoring in both THC and the chemical of interest. We illustrate the methodology by estimating exposure levels for several EGs on the Development Driller III, a rig vessel charged with drilling one of the relief wells. The model provided credible estimates in this example for geometric means, arithmetic means, variances, correlations, and regression coefficients for each group. This approach should be considered when estimating exposures in situations when multiple chemicals are correlated and have varying degrees of censoring. © The Author 2017

Comparative analysis of reflective sheeting.

DOT National Transportation Integrated Search

1981-01-01

A comparative analysis was made of the initial brightness of seibulite brand super engineering grade and scotchlite brand high intensity grade reflective sheeting under road conditions. Overhead and ground-mounted guide signs were analyzed. Human fac...

Comparative evaluation of Nano-Hydroxyapatite preparation and Calcium Sucrose Phosphate on microhardness of deciduous teeth after iron drop exposure - An in-vitro study.

PubMed

Rathi, Nilesh; Baid, Rutika; Baliga, Sudhindra; Thosar, Nilima

2017-04-01

To evaluate and compare the microhardness of deciduous teeth treated with nano-hydroxyapatite and calcium sucrose phosphate after iron drop exposure. Twenty healthy anterior deciduous teeth were collected and stored in 0.9% saline solution at room temperature. All the teeth were immersed in artificial saliva in an incubator shaker at 37° for an hour and then subjected to Vickers microhardness test at 100g load for 5 seconds. The teeth were then immersed in iron drop for 5 minutes, twice daily, rinsed with distilled water and kept in artificial saliva. This procedure was repeated for 7 days and teeth were subjected to microhardness testing. Further, the teeth were divided in two groups, each group containing 10 teeth. In group I, nanohydroxyapatite preparation and in group II, calcium sucrose phosphate were applied for 10 minutes, twice daily for 7 days and subjected again to microhardness testing again. Vickers microhardness analysis revealed that iron drop exposure to teeth caused significant decrease in microhardness ( p <0.05). Application of nanohydroxyapatite preparation in Group I showed significantly increased enamel microhardness (206.90) than that after iron drop exposure. Similarly, application of calcium sucrose phosphate in Group II showed significantly increased enamel microhardness (200.89) than that after iron drop exposure. Statistical difference was seen between the two groups, with nanohydroxyapatite preparation showing increased microhardness than calcium sucrose phosphate. Nanohydroxyapatite preparation and calcium sucrose phosphate have remineralizing effect over teeth affected by acid challenge of iron drops, nanohydroxyapatite preparation showing better results than calcium sucrose phosphate. Key words: Iron drops, Nanohydroxyapaptite, calcium sucrose phosphate, anticay.

Association of inorganic arsenic exposure with liver cancer mortality: A meta-analysis.

PubMed

Wang, Weijing; Cheng, Shuo; Zhang, Dongfeng

2014-11-01

The association of long-term inorganic arsenic (iAs) exposure through drinking water with risk of liver cancer mortality remains controversial. Therefore, we reviewed and quantitatively summarized the evidence from observational studies with a meta-analysis. Pertinent studies were identified by searching PubMed and China National Knowledge Infrastructure through May 2014 and by reviewing the reference lists of retrieved articles. Studies that reported standardized mortality ratios (SMRs) with 95% confidence interval (95% CIs) for the association of iAs in drinking water with liver cancer were eligible. The random effect model was adopted as the pooling method to generate summary effect estimates (meta-SMRs). Of the 4851 articles identified through searching databases, 7 articles including 12 studies were included in the meta-analysis. The meta-SMR with 95% CI of liver cancer for the highest versus lowest category of iAs exposure level in drinking water was 1.80 (1.61 to 2.02). Furthermore, an increased risk of liver cancer mortality was found in both females [1.80 (1.45 to 2.24)] and males [1.84 (1.56 to 2.16)]. In subgroup analysis, the meta-SMRs were 1.93 (1.72 to 2.15) for cohort studies, 1.60 (1.22 to 2.10) for ecological studies, 1.93 (1.72 to 2.15) for studies conducted in Asia, and 1.60 (1.22 to 2.10) for studies conducted in South America, respectively. After removing the 3 studies conducted by Smith et al. (having two studies separately for males and females) and Chen et al. that had a strong effect on heterogeneity, a significant association was also found [1.85 (1.72 to 1.99)]. This meta-analysis indicates that long-term iAs exposure through drinking water increases the risk of liver cancer mortality. Copyright © 2014 Elsevier Inc. All rights reserved.

Intervention strategies for carcass disposal: pareto analysis of exposures for exotic disease outbreaks.

PubMed

Delgado, João; Longhurst, Phil; Hickman, Gordon A W; Gauntlett, Daniel M; Howson, Simon F; Irving, Phil; Hart, Alwyn; Pollard, Simon J T

2010-06-15

An enhanced methodology for the policy-level prioritization of intervention options during carcass disposal is presented. Pareto charts provide a semiquantitative analysis of opportunities for multiple exposures to human health, animal health, and the wider environment during carcass disposal; they identify critical control points for risk management and assist in waste technology assessment. Eighty percent of the total availability of more than 1300 potential exposures to human, animal, or environmental receptors is represented by 16 processes, these being dominated by on-farm collection and carcass processing, reinforcing the criticality of effective controls during early stages of animal culling and waste processing. Exposures during mass burials are dominated by ground- and surface-water exposures with noise and odor nuisance prevalent for mass pyres, consistent with U.K. experience. Pareto charts are discussed in the context of other visualization formats for policy officials and promoted as a communication tool for informing the site-specific risk assessments required during the operational phases of exotic disease outbreaks.

Occupational and environmental lead exposure in Port Harcourt, Nigeria: analysis of its association with renal function indices.

PubMed

Alasia, D D; Emem-Chioma, P C; Wokoma, F S

2010-01-01

In spite of the high risk of lead exposure in Nigeria, there is a paucity of data on the occupational and environmental burden of lead exposure and its impact on human health especially its nephrotoxic effects. This study aims to assess the degree of occupational and environmental lead exposure in Port Harcourt Nigeria and the relationship between lead exposure and indices of renal function. A cross sectional comparative study of 190 aduIt subjects with occupational lead exposure and 80 matched controls. Blood lead was used as the biomarker of lead exposure. Serum urea, creatinine, uric acid, urine albumin and glomerular filtration rate were the renal function indices measured. Occupationally lead exposed subjects had higher mean blood lead 50.37 +/- 24.58 ug/dI, than controls 41.40 +/- 26.85 ug/dl (p = 0.008). The mean values of serum urea, creatinine and uric acid were significantly higher in study subjects compared to controls 3.06 +/- 0.81 mmol/L vs. 2.7 +/- 0.84 mmol/L (p = 0.002), 87.2 +/- 14.30 umol/L vs. 80.68 +/- 14.70 umol/L (p = 0.001) and 271.93 +/- 71.18 umol/L vs. 231.1 +/- 62.70 umol/L (p = 0.000) respectively. Creatinine clearance was significantly lower in subjects compared to controls 98.86 +/- 21.26 mI/min/1.72m2 vs. 108.18 +/- 25.16 mI/min/1.72m2 (p = 0.002). Blood lead correlated positively only with blood urea [r = .031, r2 = .017, p = .031] and negatively [r = -.144, r2 = .02 1, p = .018] with serum phosphate. The level of environmental and occupational lead exposure in Port Harcourt, Nigeria is high, with occupational lead exposure increasing the risk of lead toxicity and renal function impairment.

A comparative assessment of major international disasters: the need for exposure assessment, systematic emergency preparedness, and lifetime health care.

PubMed

Lucchini, Roberto G; Hashim, Dana; Acquilla, Sushma; Basanets, Angela; Bertazzi, Pier Alberto; Bushmanov, Andrey; Crane, Michael; Harrison, Denise J; Holden, William; Landrigan, Philip J; Luft, Benjamin J; Mocarelli, Paolo; Mazitova, Nailya; Melius, James; Moline, Jacqueline M; Mori, Koji; Prezant, David; Reibman, Joan; Reissman, Dori B; Stazharau, Alexander; Takahashi, Ken; Udasin, Iris G; Todd, Andrew C

2017-01-07

The disasters at Seveso, Three Mile Island, Bhopal, Chernobyl, the World Trade Center (WTC) and Fukushima had historic health and economic sequelae for large populations of workers, responders and community members. Comparative data from these events were collected to derive indications for future preparedness. Information from the primary sources and a literature review addressed: i) exposure assessment; ii) exposed populations; iii) health surveillance; iv) follow-up and research outputs; v) observed physical and mental health effects; vi) treatment and benefits; and vii) outreach activities. Exposure assessment was conducted in Seveso, Chernobyl and Fukushima, although none benefited from a timely or systematic strategy, yielding immediate and sequential measurements after the disaster. Identification of exposed subjects was overall underestimated. Health surveillance, treatment and follow-up research were implemented in Seveso, Chernobyl, Fukushima, and at the WTC, mostly focusing on the workers and responders, and to a lesser extent on residents. Exposure-related physical and mental health consequences were identified, indicating the need for a long-term health care of the affected populations. Fukushima has generated the largest scientific output so far, followed by the WTCHP and Chernobyl. Benefits programs and active outreach figured prominently in only the WTC Health Program. The analysis of these programs yielded the following lessons: 1) Know who was there; 2) Have public health input to the disaster response; 3) Collect health and needs data rapidly; 4) Take care of the affected; 5) Emergency preparedness; 6) Data driven, needs assessment, advocacy. Given the long-lasting health consequences of natural and man-made disasters, health surveillance and treatment programs are critical for management of health conditions, and emergency preparedness plans are needed to prevent or minimize the impact of future threats.

SURROGATE TISSUE ANALYSIS: MONITORING TOXICANT EXPOSURE AND HEALTH STATUS OF INACCESSIBLE TISSUES THROUGH THE ANALYSIS OF ACCESSIBLE TISSUES AND CELLS

EPA Science Inventory

Surrogate Tissue Analysis: Monitoring Toxicant Exposure And Health Status Of Inaccessible Tissues Through The Analysis Of Accessible Tissues And Cells*
John C. Rockett1, Michael E. Burczynski 2, Albert J. Fornace, Jr.3, Paul.C. Herrmann4, Stephen A. Krawetz5, and David J. Dix1...

Occupational Exposure to Nano-Objects and Their Agglomerates and Aggregates Across Various Life Cycle Stages; A Broad-Scale Exposure Study.

PubMed

Bekker, Cindy; Kuijpers, Eelco; Brouwer, Derk H; Vermeulen, Roel; Fransman, Wouter

2015-07-01

Occupational exposure to manufactured nano-objects and their agglomerates, and aggregates (NOAA) has been described in several workplace air monitoring studies. However, data pooling for general conclusions and exposure estimates are hampered by limited exposure data across the occupational life cycle of NOAA and a lack in comparability between the methods of collecting and analysing the data. By applying a consistent method of collecting and analysing the workplace exposure data, this study aimed to provide information about the occupational NOAA exposure levels across various life cycle stages of NOAA in the Netherlands which can also be used for multi-purpose use. Personal/near field task-based exposure data was collected using a multi-source exposure assessment method collecting real time particle number concentration, particle size distribution (PSD), filter-based samples for morphological, and elemental analysis and detailed contextual information. A decision logic was followed allowing a consistent and objective way of analysing the exposure data. In total, 46 measurement surveys were conducted at 15 companies covering 18 different exposure situations across various occupational life cycle stages of NOAA. Highest activity-effect levels were found during replacement of big bags (<1000-76000 # cm(-3)), mixing/dumping of powders manually (<1000-52000 # cm(-3)) and mechanically (<1000-100000 # cm(-3)), and spraying of liquid (2000-800000 # cm(-3)) showing a high variability between and within the various exposure situations. In general, a limited change in PSD was found during the activity compared to the background. This broad-scale exposure study gives a comprehensive overview of the NOAA exposure situations in the Netherlands and an indication of the levels of occupational exposure to NOAA across various life cycle of NOAA. The collected workplace exposure data and contextual information will serve as basis for future pooling of data and modelling of worker

Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth

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

Shepherd, Thomas J.; British Geological Survey, Keyworth, Nottingham; Dirks, Wendy

We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and {sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5–8 years, living in NE England. By integrating the isotope datamore » with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2–3 years for molars, first 1–2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2 µg Pb/g) with {sup 208}Pb/{sup 206}Pb (mean ±2σ: 2.126–2.079) {sup 208}Pb/{sup 206}Pb (mean ±2σ: 0.879–0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM{sub 10}, PM{sub 2.5}) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4 µgPb/g) with {sup 208}Pb/{sup 206}Pb (mean ±2σ: 2.145–2.117) {sup 208}Pb/{sup 206}Pb (mean ±2σ: 0.898–0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1–2 months) were readily identified, together with evidence that dentine provides a good proxy for

In-utero exposure to metformin for type 2 diabetes or polycystic ovary syndrome: A prospective comparative observational study.

PubMed

Diav-Citrin, Orna; Steinmetz-Shoob, Salit; Shechtman, Svetlana; Ornoy, Asher

2018-05-29

To evaluate the rate of major anomalies after first trimester (T1)-metformin exposure. Comparative, observational cohort study done at the Israeli Teratology Information Service between 2000 and 2013. 170 T1-metformin-exposed pregnancies [119 for diabetes and 51 for polycystic ovary syndrome (PCOS)] were prospectively followed-up and compared with 93 pregnancies of T1-insulin treated women and 530 non-teratogenic exposed (NTE) pregnancies. The differences in the rate of major anomalies excluding genetic/cytogenetic, and spontaneously resolved cardiovascular anomalies were not significant [4.4% (2/45) - metformin-PCOS, 1.1% (1/90) - metformin-diabetes, 2.5% (2/80) - insulin, and 1.7% (9/519) - NTE; OR adj metformin / NTE 1.77; 95% CI 0.45-7.01; OR adj insulin / NTE 1.69; 95% CI 0.35-8.11]. The rate of Cesarean section was higher in both the metformin-diabetes 51/90 (56.7%) and insulin 45/79 (57.0%) groups compared with the NTE group [138/503 (27.4%)]. Metformin-T1-exposure per se is not associated with an increased risk of major anomalies. Copyright © 2018 Elsevier Inc. All rights reserved.

Ongoing exposure versus intense periodic exposure to military conflict and terror attacks in Israel.

PubMed

Lahad, Mooli; Leykin, Dmitry

2010-12-01

The manifestation of posttraumatic stress disorder (PTSD) symptoms in two clinical samples in Israel (N = 212) was examined. Individuals suffering ongoing exposure to shelling were compared with subjects exposed to intense periodic exposure. Elevated arousal and avoidance symptoms, but not intrusion were reported in the ongoing exposure group. When compared by age, young participants in the ongoing exposure group had significantly lower PTSD scores, whereas no differences were found between participants among the intense periodic exposure age groups. No gender differences in symptoms were found among participants from intense periodic exposure, whereas in the other ongoing group the difference was in avoidance. Results are discussed in light of past research on exposure to terrorism. Copyright © 2010 International Society for Traumatic Stress Studies.

Head Impact Exposure in Youth Football: High School Ages 14 to 18 Years and Cumulative Impact Analysis

PubMed Central

Urban, Jillian E.; Davenport, Elizabeth M.; Golman, Adam J.; Maldjian, Joseph A.; Whitlow, Christopher T.; Powers, Alexander K.; Stitzel, Joel D.

2015-01-01

Sports-related concussion is the most common athletic head injury with football having the highest rate among high school athletes. Traditionally, research on the biomechanics of football-related head impact has been focused at the collegiate level. Less research has been performed at the high school level, despite the incidence of concussion among high school football players. The objective of this study is to twofold: to quantify the head impact exposure in high school football, and to develop a cumulative impact analysis method. Head impact exposure was measured by instrumenting the helmets of 40 high school football players with helmet mounted accelerometer arrays to measure linear and rotational acceleration. A total of 16,502 head impacts were collected over the course of the season. Biomechanical data were analyzed by team and by player. The median impact for each player ranged from 15.2 to 27.0 g with an average value of 21.7 (±2.4) g. The 95th percentile impact for each player ranged from 38.8 to 72.9 g with an average value of 56.4 (±10.5) g. Next, an impact exposure metric utilizing concussion injury risk curves was created to quantify cumulative exposure for each participating player over the course of the season. Impacts were weighted according to the associated risk due to linear acceleration and rotational acceleration alone, as well as the combined probability (CP) of injury associated with both. These risks were summed over the course of a season to generate risk weighted cumulative exposure. The impact frequency was found to be greater during games compared to practices with an average number of impacts per session of 15.5 and 9.4, respectively. However, the median cumulative risk weighted exposure based on combined probability was found to be greater for practices vs. games. These data will provide a metric that may be used to better understand the cumulative effects of repetitive head impacts, injury mechanisms, and head impact exposure of

Assessing workplace chemical exposures: the role of exposure monitoring.

PubMed

Harper, Martin

2004-05-01

Occupational exposure is the condition of being subjected through employment to a chemical, physical, or biological agent, or to a specific process, practice, behavior, or organization of work. Exposure to a chemical agent is typically the contact of that agent with the outer boundary of a subject, such as the respiratory system, skin, or digestive system. In occupational hygiene we are most concerned with exposure through the respiratory system, although, increasingly we are concerned with the results of dermal exposures, including those exposures to the skin that can be transferred to the mouth and digestive system. This presentation will detail methods available for assessing personal exposures to chemicals through monitoring. The results from monitoring can then be compared to established guidelines and regulations, although this is not the only rationale for making measurements. These monitoring methods are currently used around the world to establish the benchmark hazard from which risk to the worker can be predicted. The presentation will describe the general techniques for assessing exposures to the respiratory system from chemical gases and vapors, chemical dusts, and exposures to the skin from bulk chemicals or chemical contamination of surfaces. For respiratory exposures, direct-reading instruments are available for spot measurements, and for monitoring short-term fluctuations in concentration. However, most standards and regulations are based on time-integrated (time-weighted average) exposures, requiring longer-term integrative methods. Therefore, the specific focus of this review will be the methods available for full work-shift sampling. For gases and vapors this will include taking whole-air samples in canisters or polymer bags, or concentration of chemicals by absorption in liquids or adsorption on solid sorbents, with subsequent chemical analysis. Chemical concentration can take place by pumping air through the sorbing media, or by allowing

Reducing Periconceptional Methylmercury Exposure: Cost–Utility Analysis for a Proposed Screening Program for Women Planning a Pregnancy in Ontario, Canada

PubMed Central

Rennie, Colin; Coyle, Doug

2015-01-01

Background The assessment of neurodevelopmental effects in children associated with prenatal methylmercury exposure, from contaminated fish and seafood in the maternal diet, has recently been strengthened by adjustment for the negative confounding resulting from co-exposure to beneficial polyunsaturated fatty acids (PUFAs). Objectives We aimed to determine the cost-effectiveness of a periconceptional screening program of blood mercury concentration for women planning to become pregnant in Ontario, Canada. Fish intake recommendations would be provided for those found to have blood mercury levels above the intervention threshold. Methods Analysis was conducted using a combined decision tree/Markov model to compare the proposed screening intervention with standard care from a societal perspective over a lifetime horizon. We used the national blood mercury distributions of women 20–49 years of age reported in the Canadian Health Measures Survey from 2009 through 2011 to determine the cognitive deficits associated with prenatal methylmercury exposure for successful planned pregnancies. Outcomes modeled included the loss in quality of life and the remedial education costs. Value of information analysis was conducted to assess the underlying uncertainty around the model results and to identify which parameters contribute most to this uncertainty. Results The incremental cost per quality-adjusted life year (QALY) gained for the proposed screening intervention was estimated to be Can$18,051, and the expected value for a willingness to pay of Can$50,000/QALY to be Can$0.61. Conclusions Our findings suggest that the proposed periconceptional blood mercury screening program for women planning a pregnancy would be highly cost-effective from a societal perspective. The results of a value of information analysis confirm the robustness of the study’s conclusions. Citation Gaskin J, Rennie C, Coyle D. 2015. Reducing periconceptional methylmercury exposure: cost�

Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers

PubMed Central

Chang, Ellen T.; Delzell, Elizabeth

2016-01-01

ABSTRACT This systematic review and meta-analysis rigorously examines the relationship between glyphosate exposure and risk of lymphohematopoietic cancer (LHC) including NHL, Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia. Meta-relative risks (meta-RRs) were positive and marginally statistically significant for the association between any versus no use of glyphosate and risk of NHL (meta-RR = 1.3, 95% confidence interval (CI) = 1.0–1.6, based on six studies) and MM (meta-RR = 1.4, 95% CI = 1.0–1.9; four studies). Associations were statistically null for HL (meta-RR = 1.1, 95% CI = 0.7–1.6; two studies), leukemia (meta-RR = 1.0, 95% CI = 0.6–1.5; three studies), and NHL subtypes except B-cell lymphoma (two studies each). Bias and confounding may account for observed associations. Meta-analysis is constrained by few studies and a crude exposure metric, while the overall body of literature is methodologically limited and findings are not strong or consistent. Thus, a causal relationship has not been established between glyphosate exposure and risk of any type of LHC. PMID:27015139

Advanced Exposure Metrics For Chemical Risk Analysis: Systems Biology and 'Omic-based Biomarkers for Exposure Reconstruction

EPA Science Inventory

Direct measurement of human exposure to environmental contaminants in real time (when the exposure is actually occurring) is rare and difficult to obtain. This frustrates both exposure assessments and investigations into the linkage between chemical exposure and human disease. ...

Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies.

PubMed

Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping

2015-01-01

Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed. Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15). Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed. The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.

Exposure to Fluoride in Drinking Water and Hip Fracture Risk: A Meta-Analysis of Observational Studies

PubMed Central

Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping

2015-01-01

Background Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. Methods PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed. Results Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96–1.15). Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle–Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle–Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed. Conclusion The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk. PMID:26020536

Recurrence quantification analysis to characterize cyclical components of environmental elemental exposures during fetal and postnatal development

PubMed Central

Austin, Christine; Gennings, Chris; Tammimies, Kristiina; Bölte, Sven; Arora, Manish

2017-01-01

Environmental exposures to essential and toxic elements may alter health trajectories, depending on the timing, intensity, and mixture of exposures. In epidemiologic studies, these factors are typically analyzed as a function of elemental concentrations in biological matrices measured at one or more points in time. Such an approach, however, fails to account for the temporal cyclicity in the metabolism of environmental chemicals, which if perturbed may lead to adverse health outcomes. Here, we conceptualize and apply a non-linear method–recurrence quantification analysis (RQA)–to quantify cyclical components of prenatal and early postnatal exposure profiles for elements essential to normal development, including Zn, Mn, Mg, and Ca, and elements associated with deleterious health effects or narrow tolerance ranges, including Pb, As, and Cr. We found robust evidence of cyclical patterns in the metabolic profiles of nutrient elements, which we validated against randomized twin-surrogate time-series, and further found that nutrient dynamical properties differ from those of Cr, As, and Pb. Furthermore, we extended this approach to provide a novel method of quantifying dynamic interactions between two environmental exposures. To achieve this, we used cross-recurrence quantification analysis (CRQA), and found that elemental nutrient-nutrient interactions differed from those involving toxicants. These rhythmic regulatory interactions, which we characterize in two geographically distinct cohorts, have not previously been uncovered using traditional regression-based approaches, and may provide a critical unit of analysis for environmental and dietary exposures in epidemiological studies. PMID:29112980

No Need for Lopinavir Dose Adjustment during Pregnancy: a Population Pharmacokinetic and Exposure-Response Analysis in Pregnant and Nonpregnant HIV-Infected Subjects.

PubMed

Salem, Ahmed Hamed; Jones, Aksana Kaefer; Santini-Oliveira, Marilia; Taylor, Graham P; Patterson, Kristine B; Nilius, Angela M; Klein, Cheri Enders

2016-01-01

Lopinavir-ritonavir is frequently prescribed to HIV-1-infected women during pregnancy. Decreased lopinavir exposure has been reported during pregnancy, but the clinical significance of this reduction is uncertain. This analysis aimed to evaluate the need for lopinavir dose adjustment during pregnancy. We conducted a population pharmacokinetic analysis of lopinavir and ritonavir concentrations collected from 84 pregnant and 595 nonpregnant treatment-naive and -experienced HIV-1-infected subjects enrolled in six clinical studies. Lopinavir-ritonavir doses in the studies ranged between 400/100 and 600/150 mg twice daily. In addition, linear mixed-effect analysis was used to compare the area under the concentration-time curve from 0 to 12 h (AUC0-12) and concentration prior to dosing (Cpredose) in pregnant women and nonpregnant subjects. The relationship between lopinavir exposure and virologic suppression in pregnant women and nonpregnant subjects was evaluated. Population pharmacokinetic analysis estimated 17% higher lopinavir clearance in pregnant women than in nonpregnant subjects. Lopinavir clearance values postpartum were 26.4% and 37.1% lower than in nonpregnant subjects and pregnant women, respectively. As the tablet formulation was estimated to be 20% more bioavailable than the capsule formulation, no statistically significant differences between lopinavir exposure in pregnant women receiving the tablet formulation and nonpregnant subjects receiving the capsule formulation were identified. In the range of lopinavir AUC0-12 or Cpredose values observed in the third trimester, there was no correlation between lopinavir exposure and viral load or proportion of subjects with virologic suppression. Similar efficacy was observed between pregnant women and nonpregnant subjects receiving lopinavir-ritonavir at 400/100 mg twice daily. The pharmacokinetic and pharmacodynamic results support the use of a lopinavir-ritonavir 400/100-mg twice-daily dose during pregnancy

A Meta-Analysis Summarizing the Effects of Pornography II: Aggression after Exposure.

ERIC Educational Resources Information Center

Allen, Mike; And Others

1995-01-01

Examines by meta-analysis the effect that exposure to pornography produces on aggressive behavior under laboratory conditions considering a variety of possible moderating conditions. Demonstrates a homogeneous set of results showing that pictorial nudity reduces subsequent violent behavior, but that depictions of nonviolent sexual behavior and…

EXPERIENCES WITH USING PROBABILISTIC EXPOSURE ANALYSIS METHODS IN THE U.S. EPA

EPA Science Inventory

Over the past decade various Offices and Programs within the U.S. EPA have either initiated or increased the development and application of probabilistic exposure analysis models. These models have been applied to a broad range of research or regulatory problems in EPA, such as e...

SFDT-1 Camera Pointing and Sun-Exposure Analysis and Flight Performance

NASA Technical Reports Server (NTRS)

White, Joseph; Dutta, Soumyo; Striepe, Scott

2015-01-01

The Supersonic Flight Dynamics Test (SFDT) vehicle was developed to advance and test technologies of NASA's Low Density Supersonic Decelerator (LDSD) Technology Demonstration Mission. The first flight test (SFDT-1) occurred on June 28, 2014. In order to optimize the usefulness of the camera data, analysis was performed to optimize parachute visibility in the camera field of view during deployment and inflation and to determine the probability of sun-exposure issues with the cameras given the vehicle heading and launch time. This paper documents the analysis, results and comparison with flight video of SFDT-1.

A systematic uncertainty analysis of an evaluative fate and exposure model.

PubMed

Hertwich, E G; McKone, T E; Pease, W S

2000-08-01

Multimedia fate and exposure models are widely used to regulate the release of toxic chemicals, to set cleanup standards for contaminated sites, and to evaluate emissions in life-cycle assessment. CalTOX, one of these models, is used to calculate the potential dose, an outcome that is combined with the toxicity of the chemical to determine the Human Toxicity Potential (HTP), used to aggregate and compare emissions. The comprehensive assessment of the uncertainty in the potential dose calculation in this article serves to provide the information necessary to evaluate the reliability of decisions based on the HTP A framework for uncertainty analysis in multimedia risk assessment is proposed and evaluated with four types of uncertainty. Parameter uncertainty is assessed through Monte Carlo analysis. The variability in landscape parameters is assessed through a comparison of potential dose calculations for different regions in the United States. Decision rule uncertainty is explored through a comparison of the HTP values under open and closed system boundaries. Model uncertainty is evaluated through two case studies, one using alternative formulations for calculating the plant concentration and the other testing the steady state assumption for wet deposition. This investigation shows that steady state conditions for the removal of chemicals from the atmosphere are not appropriate and result in an underestimate of the potential dose for 25% of the 336 chemicals evaluated.

Occupational Exposure to Endocrine-Disrupting Chemicals and Birth Weight and Length of Gestation: A European Meta-Analysis

PubMed Central

Birks, Laura; Casas, Maribel; Garcia, Ana M.; Alexander, Jan; Barros, Henrique; Bergström, Anna; Bonde, Jens Peter; Burdorf, Alex; Costet, Nathalie; Danileviciute, Asta; Eggesbø, Merete; Fernández, Mariana F.; González-Galarzo, M. Carmen; Hanke, Wojciech; Jaddoe, Vincent; Kogevinas, Manolis; Kull, Inger; Lertxundi, Aitana; Melaki, Vasiliki; Andersen, Anne-Marie Nybo; Olea, Nicolás; Polanska, Kinga; Rusconi, Franca; Santa-Marina, Loreto; Santos, Ana Cristina; Vrijkotte, Tanja; Zugna, Daniela; Nieuwenhuijsen, Mark; Cordier, Sylvaine; Vrijheid, Martine

2016-01-01

Background: Women of reproductive age can be exposed to endocrine-disrupting chemicals (EDCs) at work, and exposure to EDCs in pregnancy may affect fetal growth. Objectives: We assessed whether maternal occupational exposure to EDCs during pregnancy as classified by application of a job exposure matrix was associated with birth weight, term low birth weight (LBW), length of gestation, and preterm delivery. Methods: Using individual participant data from 133,957 mother–child pairs in 13 European cohorts spanning births from 1994 through 2011, we linked maternal job titles with exposure to 10 EDC groups as assessed through a job exposure matrix. For each group, we combined the two levels of exposure categories (possible and probable) and compared birth outcomes with the unexposed group (exposure unlikely). We performed meta-analyses of cohort-specific estimates. Results: Eleven percent of pregnant women were classified as exposed to EDCs at work during pregnancy, based on job title. Classification of exposure to one or more EDC group was associated with an increased risk of term LBW [odds ratio (OR) = 1.25; 95% CI: 1.04, 1.49], as were most specific EDC groups; this association was consistent across cohorts. Further, the risk increased with increasing number of EDC groups (OR = 2.11; 95% CI: 1.10, 4.06 for exposure to four or more EDC groups). There were few associations (p < 0.05) with the other outcomes; women holding job titles classified as exposed to bisphenol A or brominated flame retardants were at higher risk for longer length of gestation. Conclusion: Results from our large population-based birth cohort design indicate that employment during pregnancy in occupations classified as possibly or probably exposed to EDCs was associated with an increased risk of term LBW. Citation: Birks L, Casas M, Garcia AM, Alexander J, Barros H, Bergström A, Bonde JP, Burdorf A, Costet N, Danileviciute A, Eggesbø M, Fernández MF, González-Galarzo MC, Gražulevičienė R

Occupational exposure to pesticides and prostate cancer: a systematic review and meta-analysis.

PubMed

Lewis-Mikhael, Anne-Mary; Bueno-Cavanillas, Aurora; Ofir Giron, Talia; Olmedo-Requena, Rocío; Delgado-Rodríguez, Miguel; Jiménez-Moleón, José Juan

2016-02-01

Epidemiological studies on exposure to pesticides and risk of prostate cancer (PC) provide inconsistent results. We aimed to explore various potential sources of heterogeneity not previously assessed and to derive updated risk estimates from homogenous studies. We searched PubMed, Web of Science and Scopus databases for case-control and cohort studies published from 1985 to April 2014. We assessed the quality of the articles using the Newcastle-Ottawa Scale. Pooled estimates were calculated using random-effects models. Heterogeneity was explored using subset analyses and metaregression. Fifty-two studies were included in the review and 25 in the meta-analysis. No association was found between low exposure to pesticides and PC, but association was significant for high exposure, pooled OR 1.33 (1.02 to 1.63), I(2)=44.8%, p=0.024. Heterogeneity was explained by a number of variables including method used to assess exposure. Pooled OR was weak and non-significant for studies measuring serum pesticide level, 1.12 (0.74 to 1.50), I(2)=0.00%, p=0.966. For studies applying self-reporting of exposure, pooled estimate was 1.34 (0.91 to 1.77), I(2)=0.00%, p=0.493, while a high significant association was detected for grouped exposure assessment, 2.24 (1.36 to 3.11), I(2)=0.00%, p=0.955. In spite of a weak significant association detected when pooling ORs for high occupational exposure to pesticides, the magnitude of the association was related to the method of exposure assessment used by the original studies. A family history-pesticide exposure interaction was also observed for a number of pesticides. 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/

A comparative ecotoxicity analysis of α- and γ-phase aluminium oxide nanoparticles towards a freshwater bacterial isolate Bacillus licheniformis.

PubMed

Pakrashi, Sunandan; Kumar, Deepak; Iswarya, V; Bhuvaneshwari, M; Chandrasekaran, N; Mukherjee, Amitava

2014-12-01

Crystalline structure of nanoparticles may influence their physicochemical behaviour as well as their toxicological impact on biota. The differences in orientation of the atoms result in the variations in chemical stability. Thus, toxicological impacts of different crystalline phases of aluminium oxide nanoparticles are expected to vary. The present study brings out a comparative toxicity analysis of γ-phase and α-phase aluminium oxide nanoparticles of comparable hydrodynamic size range towards a freshwater bacterial isolate Bacillus licheniformis at low exposure concentrations (5, 1, 0.5 and 0.05 µg/mL). Upon 2-h exposure, the α-aluminium oxide particles showed lower toxicity than the γ-phase aluminium oxide. The lower level of oxidative stress generation and cell membrane damage in case of the α-phase aluminium oxide nanoparticles substantiated the toxicity results. The involvement of protein, lipopolysaccharides in nanoparticle-cell surface interaction, was noted in both the cases. To conclude, the crystallinity of aluminium oxide nanoparticles played an important role in the interaction and the toxicity response.

Analysis of occupational exposures to blood registered in the General Hospital in Zabrze in the years 2006-2015

PubMed

Kocur, Ewelina; Śliwa-Rak, Bożena; Grosicki, Sebastian

Viral hepatitis B and C are the most common occupational diseases among health care workers. Infection occurs during performance of medical procedures which carries a risk of contact with biological material derived from a patient. The aim of the study was to analyse cases of occupational exposure to biological material as recorded by the employees of the City Hospital in Zabrze, to attempt to determine which medical procedures are of greatest risk of occupational exposure, and to identify the most important actions aimed at reduction of their number. The analysis included all cases of exposure to biological material derived from a patient, which were reported by employees of the City Hospital in Zabrze in 2006–2015. The analysis included the percentage of exposure for individual occupational groups and wards of the hospital, the type of the procedure at performance of which the exposure occurred, the type of tools affecting the skin continuity and proper conduct of the proceedings of the employee after exposure. The occupational group most frequently affected by exposures were nurses/midwives. This occupational group accounted for 41.2% of all exposed people. The next highest percentage exposure of 5.9% concerned the occupational group of doctors, further paramedics with 3.8%, orderlies – 2.6%, nurses – 2.4%. The ward of internal diseases had most frequent occurrences of exposure, but the percentage of exposure was the highest for the operating room – 7.5%. Most often the injury occurred during sampling venous blood – 20.6%. People assisting at procedures performed with a use of sharp equipment made 13.4% of employees exposed to blood. Orderlies were the third occupational group in terms of most common cuts. The employees were injured by cutting themselves while disposing of waste as often as when performing/assisting with a surgery. In 24.7% of cases immediately after exposure to biological material the employees behaved contrary to the procedure. List

Embedded Hyperchaotic Generators: A Comparative Analysis

NASA Astrophysics Data System (ADS)

Sadoudi, Said; Tanougast, Camel; Azzaz, Mohamad Salah; Dandache, Abbas

In this paper, we present a comparative analysis of FPGA implementation performances, in terms of throughput and resources cost, of five well known autonomous continuous hyperchaotic systems. The goal of this analysis is to identify the embedded hyperchaotic generator which leads to designs with small logic area cost, satisfactory throughput rates, low power consumption and low latency required for embedded applications such as secure digital communications between embedded systems. To implement the four-dimensional (4D) chaotic systems, we use a new structural hardware architecture based on direct VHDL description of the forth order Runge-Kutta method (RK-4). The comparative analysis shows that the hyperchaotic Lorenz generator provides attractive performances compared to that of others. In fact, its hardware implementation requires only 2067 CLB-slices, 36 multipliers and no block RAMs, and achieves a throughput rate of 101.6 Mbps, at the output of the FPGA circuit, at a clock frequency of 25.315 MHz with a low latency time of 316 ns. Consequently, these good implementation performances offer to the embedded hyperchaotic Lorenz generator the advantage of being the best candidate for embedded communications applications.

Occupational styrene exposure for twelve product categories in the reinforced-plastics industry.

PubMed

Lemasters, G K; Carson, A; Samuels, S J

1985-08-01

Approximately 1500 occupational styrene exposure values from 28 reinforced-plastic manufacturers were collected retrospectively from companies and state and federal agencies. This report describes the major types of manufacturing processes within the reinforced-plastics industry and reports on the availability, collection and analysis of historical exposure information. Average exposure to styrene in most open-mold companies (24-82 ppm) was generally 2-3 times the exposure in press-mold companies (11-26 ppm). Manufacturers of smaller boats had mean styrene exposures of 82 ppm as compared to 37 ppm for yacht companies. There was considerable overlap in styrene exposure among job titles classified as directly exposed within open- and press-mold processing.

Prioritization of pesticides based on daily dietary exposure potential as determined from the SHEDS model.

PubMed

Melnyk, Lisa Jo; Wang, Zhaohui; Li, Zhilin; Xue, Jianping

2016-10-01

A major pathway for exposure to many pesticides is through diet. The objectives were to rank pesticides by comparing their calculated daily dietary exposure as determined by EPA's Stochastic Human Exposure and Dose Simulation (SHEDS) to single pesticides for different age groups to acceptable daily intakes (ADI), characterize pesticide trends in exposures over different time periods, and determine commodities contributing to pesticide exposures. SHEDS was applied, using Pesticide Data Program (PDP) (1991-2011) and pesticide usage data on crops from USDA combined with NHANES dietary consumption data, to generate exposure estimates by age group. ADI data collected from EPA, WHO, and other sources were used to rank pesticides based on relativeness of the dietary exposure potential to ADI by age groups. Sensitivity analysis provided trends in pesticide exposures. Within SHEDS, commodities contributing the majority of pesticides with greatest exposure potential were determined. The results indicated that the highest ranking pesticides were methamidophos and diazinon which exceeded 100% of the ADI. Sensitivity analysis indicated that exposure to methamidophos, diazinon, malathion, ethion and formetanate hydrochloride had a marked decrease from 1991-1999 to 2000-2011. Contributions analysis indicated that apples, mushroom, carrots, and lettuce contributed to diazinon exposure. Beans and pepper contributed to methamidophos exposure. Published by Elsevier Ltd.

Occupational exposure to chrome VI compounds in French companies: results of a national campaign to measure exposure (2010-2013).

PubMed

Vincent, Raymond; Gillet, Martine; Goutet, Pierre; Guichard, Christine; Hédouin-Langlet, Catherine; Frocaut, Anne Marie; Lambert, Pierre; Leray, Fabrice; Mardelle, Patricia; Dorotte, Michel; Rousset, Davy

2015-01-01

A campaign to measure exposure to hexavalent chromium compounds was carried out in France by the seven CARSAT chemistry laboratories, CRAMIF laboratory, and INRS over the 2010-2013 period. The survey included 99 companies involved in various activity sectors. The inhalable fraction of airborne particles was sampled, and exposure levels were determined using ion chromatography analysis combined with post-column derivatization and UV detection. The quality of the measurement results was guaranteed by an inter-laboratory comparison system involving all the laboratories participating in this study. Exposure levels frequently exceeded the French occupational exposure limit value (OELV) of 1 µg m(-3), in activities such as thermal metallization and manufacturing and application of paint in the aeronautics sector. The results also reveal a general trend for a greater proportion of soluble Chromium VI (Cr VI) compounds compared with insoluble compounds. Qualitative and quantitative information relating to the presence of other metallic compounds in the air of workplaces is also provided, for example for Cr III, Ni, Fe, etc. The sampling strategy used and the measurement method are easy to implement, making it possible to check occupational exposure with a view to comparing it to an 8 h-OELV of 1 µg m(-3). © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Non-occupational exposure to asbestos and risk of pleural mesothelioma: review and meta-analysis.

PubMed

Marsh, Gary M; Riordan, Alexander S; Keeton, Kara A; Benson, Stacey M

2017-11-01

To conduct an updated literature review and meta-analysis of studies of pleural malignant mesothelioma (PMM) risk among persons exposed to asbestos non-occupationally (household and neighbourhood). We performed a literature search for articles available in the National Center for Biotechnology Information's PubMed database published between 1967 and 2016. Meta-analyses were conducted to calculate pooled PMM risk estimates, stratifying for household or neighbourhood exposure to asbestos and/or predominant asbestos fibre type (chrysotile, amphibole or mixed). Eighteen studies in 12 countries comprising 665 cases met the meta-analysis inclusion criteria. We identified 13 estimates of PMM risk from neighbourhood exposures, 10 from household and one from mixed exposure, and combined the estimates using random-effects models. The overall meta-relative risk (meta-RR) was 5.9 (95% CI 4.4 to 8.7). The meta-RRs for household and neighbourhood exposures were 5.4 (95% CI 2.6 to 11.2) and 6.9 (95% CI 4.2 to 11.4), respectively. We observed trends in risk in relation to fibre type for both household and neighbourhood studies. For chrysotile, mixed and amphibole fibres, respectively, meta-RRs for neighbourhood studies were 3.8 (95% CI 0.4 to 38.4), 8.4 (95% CI 4.7 to 14.9) and 21.1 (95% CI 5.3 to 84.5) and meta-RRs for household studies were 4.0 (95% CI 0.8 to 18.8), 5.3 (95% CI 1.9 to 15.0) and 21.1 (95% CI 2.8 to 156.0). PMM risks from non-occupational asbestos exposure are consistent with the fibre-type potency response observed in occupational settings. By relating our findings to knowledge of exposure-response relationships in occupational settings, we can better evaluate PMM risks in communities with ambient asbestos exposures from industrial or other sources. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

UNCERTAINTY ANALYSIS OF TCE USING THE DOSE EXPOSURE ESTIMATING MODEL (DEEM) IN ACSL

EPA Science Inventory

The ACSL-based Dose Exposure Estimating Model(DEEM) under development by EPA is used to perform art uncertainty analysis of a physiologically based pharmacokinetic (PSPK) model of trichloroethylene (TCE). This model involves several circulating metabolites such as trichloroacet...

Recent advances in simultaneous analysis of bisphenol A and its conjugates in human matrices: Exposure biomarker perspectives.

PubMed

Andra, Syam S; Austin, Christine; Yang, Juan; Patel, Dhavalkumar; Arora, Manish

2016-12-01

Human exposures to bisphenol A (BPA) has attained considerable global health attention and represents one of the leading environmental contaminants with potential adverse health effects including endocrine disruption. Current practice of measuring of exposure to BPA includes the measurement of unconjugated BPA (aglycone) and total (both conjugated and unconjugated) BPA; the difference between the two measurements leads to estimation of conjugated forms. However, the measurement of BPA as the end analyte leads to inaccurate estimates from potential interferences from background sources during sample collection and analysis. BPA glucuronides (BPAG) and sulfates (BPAS) represent better candidates for biomarkers of BPA exposure, since they require in vivo metabolism and are not prone to external contamination. In this work, the primary focus was to review the current state of the art in analytical methods available to quantitate BPA conjugates. The entire analytical procedure for the simultaneous extraction and detection of aglycone BPA and conjugates is covered, from sample pre-treatment, extraction, separation, ionization, and detection. Solid phase extraction coupled with liquid chromatograph and tandem mass spectrometer analysis provides the most sensitive detection and quantification of BPA conjugates. Discussed herein are the applications of BPA conjugates analysis in human exposure assessment studies. Measuring these potential biomarkers of BPA exposure has only recently become analytically feasible and there are limitations and challenges to overcome in biomonitoring studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Solar ultraviolet and the occupational radiant exposure of Queensland school teachers: A comparative study between teaching classifications and behavior patterns.

PubMed

Downs, Nathan J; Harrison, Simone L; Chavez, Daniel R Garzon; Parisi, Alfio V

2016-05-01

Classroom teachers located in Queensland, Australia are exposed to high levels of ambient solar ultraviolet as part of the occupational requirement to provide supervision of children during lunch and break times. We investigated the relationship between periods of outdoor occupational radiant exposure and available ambient solar radiation across different teaching classifications and schools relative to the daily occupational solar ultraviolet radiation (HICNIRP) protection standard of 30J/m(2). Self-reported daily sun exposure habits (n=480) and personal radiant exposures were monitored using calibrated polysulphone dosimeters (n=474) in 57 teaching staff from 6 different schools located in tropical north and southern Queensland. Daily radiant exposure patterns among teaching groups were compared to the ambient UV-Index. Personal sun exposures were stratified among teaching classifications, school location, school ownership (government vs non-government), and type (primary vs secondary). Median daily radiant exposures were 15J/m(2) and 5J/m(2)HICNIRP for schools located in northern and southern Queensland respectively. Of the 474 analyzed dosimeter-days, 23.0% were found to exceed the solar radiation protection standard, with the highest prevalence found among physical education teachers (57.4% dosimeter-days), followed by teacher aides (22.6% dosimeter-days) and classroom teachers (18.1% dosimeter-days). In Queensland, peak outdoor exposure times of teaching staff correspond with periods of extreme UV-Index. The daily occupational HICNIRP radiant exposure standard was exceeded in all schools and in all teaching classifications. Copyright © 2016 Elsevier B.V. All rights reserved.

Childhood autism spectrum disorders and exposure to nitrogen dioxide, and particulate matter air pollution: A review and meta-analysis.

PubMed

Flores-Pajot, Marie-Claire; Ofner, Marianna; Do, Minh T; Lavigne, Eric; Villeneuve, Paul J

2016-11-01

Genetic and environmental factors have been recognized to play an important role in autism. The possibility that exposure to outdoor air pollution increases the risk of autism spectrum disorder (ASD) has been an emerging area of research. Herein, we present a systematic review, and meta-analysis of published epidemiological studies that have investigated these associations. We undertook a comprehensive search strategy to identify studies that investigated outdoor air pollution and autism in children. Overall, seven cohorts and five case-control studies met our inclusion criteria for the meta-analysis. We summarized the associations between exposure to air pollution and ASD based on the following critical exposure windows: (i) first, second and third trimester of pregnancy, (ii) entire pregnancy, and (iii) postnatal period. Random effects meta-analysis modeling was undertaken to derive pooled risk estimates for these exposures across the studies. The meta-estimates for the change in ASD associated with a 10μg/m 3 increase in exposure in PM 2.5 and 10 ppb increase in NO 2 during pregnancy were 1.34 (95% CI:0.83, 2.17) and 1.05 (95% CI:0.99, 1.11), respectively. Stronger associations were observed for exposures received after birth, but these estimates were unstable as they were based on only two studies. O 3 exposure was weakly associated with ASD during the third trimester of pregnancy and during the entire pregnancy, however, these estimates were also based on only two studies. Our meta-analysis support the hypothesis that exposure to ambient air pollution is associated with an increased risk of autism. Our findings should be interpreted cautiously due to relatively small number of studies, and several studies were unable to control for other key risk factors. Copyright © 2016 Elsevier Inc. All rights reserved.

Respiratory Symptoms Following Wildfire Smoke Exposure

PubMed Central

Mirabelli, Maria C.; Künzli, Nino; Avol, Edward; Gilliland, Frank D.; Gauderman, W. James; McConnell, Rob; Peters, John M.

2015-01-01

Background Associations between exposure to smoke during wild-fire events and respiratory symptoms are well documented, but the role of airway size remains unclear. We conducted this analysis to assess whether small airway size modifies these relationships. Methods We analyzed data from 465 nonasthmatic 16- to 19-year-old participants in the Children’s Health Study. Following an outbreak of wildfires in 2003, each student completed a questionnaire about smoke exposure, dry and wet cough, wheezing, and eye symptoms. We used log-binomial regression to evaluate associations between smoke exposure and fire-related health symptoms, and to assess modification of the associations by airway size. As a marker of airway size, we used the ratio of maximum midexpiratory flow to forced vital capacity. Results Forty percent (186 of 465) of this population (including students from 11 of 12 surveyed communities) reported the odor of wildfire smoke at home. We observed increased respiratory and eye symptoms with increasing frequency of wildfire smoke exposure. Associations between smoke exposure and having any of 4 respiratory symptoms were stronger in the lowest quartile of the lung function ratio (eg, fire smoke 6+ days: prevalence ratio: 3.8; 95% confidence interval (CI = 2.0 –7.2), compared with the remaining quartiles (fire smoke 6+ days: prevalence ratio = 2.0; 1.2–3.2). Analysis of individual symptoms suggests that this interaction may be strongest for effects on wheezing. Conclusions Small airways may serve as a marker of susceptibility to effects of wildfire smoke. Future studies should investigate the role of airway size for more common exposures and should include persons with asthma. PMID:19276978

Complexities of sibling analysis when exposures and outcomes change with time and birth order.

PubMed

Sudan, Madhuri; Kheifets, Leeka I; Arah, Onyebuchi A; Divan, Hozefa A; Olsen, Jørn

2014-01-01

In this study, we demonstrate the complexities of performing a sibling analysis with a re-examination of associations between cell phone exposures and behavioral problems observed previously in the Danish National Birth Cohort. Children (52,680; including 5441 siblings) followed up to age 7 were included. We examined differences in exposures and behavioral problems between siblings and non-siblings and by birth order and birth year. We estimated associations between cell phone exposures and behavioral problems while accounting for the random family effect among siblings. The association of behavioral problems with both prenatal and postnatal exposure differed between siblings (odds ratio (OR): 1.07; 95% confidence interval (CI): 0.69-1.66) and non-siblings (OR: 1.54; 95% CI: 1.36-1.74) and within siblings by birth order; the association was strongest for first-born siblings (OR: 1.72; 95% CI: 0.86-3.42) and negative for later-born siblings (OR: 0.63; 95% CI: 0.31-1.25), which may be because of increases in cell phone use with later birth year. Sibling analysis can be a powerful tool for (partially) accounting for confounding by invariant unmeasured within-family factors, but it cannot account for uncontrolled confounding by varying family-level factors, such as those that vary with time and birth order.

Whole genome expression analysis in primary bronchial epithelial cells after exposure to sulphur mustard.

PubMed

Jowsey, Paul A; Blain, Peter G

2014-11-04

Sulphur mustard (SM) is a highly toxic chemical agent and poses a current threat to both civilians and military personnel in the event of a deliberate malicious release. Acute SM toxicity develops over the course of several hours and mainly affects the skin and mucosal surfaces of the eyes and respiratory system. In cases of acute severe exposure, significant lung injury can result in respiratory failure and death. Systemic levels of SM can also be fatal, frequently due to immunodepletion and the subsequent development of secondary infections. Whilst the physical effects associated with SM exposure are well documented, the molecular mechanisms mediating these changes are poorly understood, hindering the development of an effective therapeutic strategy. To gain a better understanding of the mechanism of SM toxicity, this study investigated whole genome transcriptional changes after SM in primary human bronchial epithelial cells, as a model for inhalation exposure. The analysis revealed >400 transcriptional changes associated with SM exposure. Pathways analysis confirmed the findings of previous studies suggesting that DNA damage, cell cycle arrest, cell death and inflammation were important components of SM toxicity. In addition, several other interesting observations were made, suggesting that protein oxidation as well as effects on the mitotic apparatus may contribute to SM toxicity. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Systematic Review with Network Meta-Analysis: Comparative Efficacy of Biologics in the Treatment of Moderately to Severely Active Ulcerative Colitis.

PubMed

Vickers, Adrian D; Ainsworth, Claire; Mody, Reema; Bergman, Annika; Ling, Caroline S; Medjedovic, Jasmina; Smyth, Michael

2016-01-01

Biological therapies are increasingly used to treat ulcerative colitis (UC). To compare the efficacy of biologics in adults with moderately-to-severely active UC, stratified by prior exposure to anti-tumour necrosis factor (anti-TNF) therapy. A systematic literature review was undertaken to identify studies of biologics approved for UC. Network meta-analysis was conducted for endpoints at induction and maintenance. Seven studies were included in the meta-analysis of induction treatment for anti-TNF therapy-naïve patients. All biologics were more effective than placebo in inducing clinical response, clinical remission, and mucosal healing. Infliximab demonstrated a statistically significant improvement over adalimumab in clinical response (odds ratio [OR] [95% credible interval (CrI)]: 2.19 [1.35-3.55]), clinical remission (OR [95% CrI]: 2.81 [1.49-5.49]), and mucosal healing (OR [95% CrI]: 2.23 [1.21-4.14]); there were no other significant differences between biologics for induction efficacy. Five studies were included in the meta-analysis of maintenance treatment, two studies rerandomised responder patients at end of induction, and three followed the same patients 'straight through'. To account for design differences, the number of responders at end of induction was assumed to be equivalent to the number rerandomised. Vedolizumab showed significantly different durable clinical response from comparators (OR [95% CrI] infliximab 3.18 [1.14-9.20], golimumab 2.33 [1.04-5.41], and adalimumab 3.96 [1.67-9.84]). In anti-TNF therapy-experienced patients, only vedolizumab and adalimumab could be compared. At induction, no significant differences in efficacy were seen. During maintenance, vedolizumab showed significantly improved rates of mucosal healing versus adalimumab (OR [95% CrI]: 6.72 [1.36-41.0]). This study expands the understanding of comparative efficacies of biologic treatments for UC, encompassing outcomes and populations not previously studied. All biologic

Child development following in utero exposure

PubMed Central

Shallcross, R.; Bromley, R.L.; Irwin, B.; Bonnett, L.J.; Morrow, J.

2011-01-01

Objective: Children born to women with epilepsy (WWE), exposed in utero to levetiracetam (LEV, n = 51), were assessed for early cognitive development and compared to children exposed to sodium valproate in utero (VPA, n = 44) and a group of children representative of the general population (n = 97). Methods: Children were recruited prospectively from 2 cohorts in the United Kingdom and assessed using the Griffiths Mental Development Scale (1996), aged <24 months. Information regarding maternal demographics were collected and controlled for. This is an observational study with researchers not involved in the clinical management of the WWE. Results: On overall developmental ability, children exposed to LEV obtained higher developmental scores when compared to children exposed to VPA (p < 0.001). When compared, children exposed to LEV did not differ from control children (p = 0.62) on overall development. Eight percent of children exposed to LEV in utero fell within the below average range (DQ score of <84), compared with 40% of children exposed to VPA. After controlling for maternal epilepsy and demographic factors using linear regression analysis, exposure to LEV in utero was not associated with outcome (p = 0.67). Conversely, when compared with VPA exposure, LEV exposure was associated with higher scores for the overall developmental quotient (p < 0.001). Conclusion: Children exposed to LEV in utero are not at an increased risk of delayed early cognitive development under the age of 24 months. LEV may therefore be a preferable drug choice, where appropriate, for WWE prior to and of childbearing age. PMID:21263139

Agent Orange exposure and prevalence of self-reported diseases in Korean Vietnam veterans.

PubMed

Yi, Sang-Wook; Ohrr, Heechoul; Hong, Jae-Seok; Yi, Jee-Jeon

2013-09-01

The aim of this study was to evaluate the association between Agent Orange exposure and self-reported diseases in Korean Vietnam veterans. A postal survey of 114 562 Vietnam veterans was conducted. The perceived exposure to Agent Orange was assessed by a 6-item questionnaire. Two proximity-based Agent Orange exposure indices were constructed using division/brigade-level and battalion/company-level unit information. Adjusted odds ratios (ORs) for age and other confounders were calculated using a logistic regression model. The prevalence of all self-reported diseases showed monotonically increasing trends as the levels of perceived self-reported exposure increased. The ORs for colon cancer (OR, 1.13), leukemia (OR, 1.56), hypertension (OR, 1.03), peripheral vasculopathy (OR, 1.07), enterocolitis (OR, 1.07), peripheral neuropathy (OR, 1.07), multiple nerve palsy (OR, 1.14), multiple sclerosis (OR, 1.24), skin diseases (OR, 1.05), psychotic diseases (OR, 1.07) and lipidemia (OR, 1.05) were significantly elevated for the high exposure group in the division/brigade-level proximity-based exposure analysis, compared to the low exposure group. The ORs for cerebral infarction (OR, 1.08), chronic bronchitis (OR, 1.05), multiple nerve palsy (OR, 1.07), multiple sclerosis (OR, 1.16), skin diseases (OR, 1.05), and lipidemia (OR, 1.05) were significantly elevated for the high exposure group in the battalion/company-level analysis. Korean Vietnam veterans with high exposure to Agent Orange experienced a higher prevalence of several self-reported chronic diseases compared to those with low exposure by proximity-based exposure assessment. The strong positive associations between perceived self-reported exposure and all self-reported diseases should be evaluated with discretion because the likelihood of reporting diseases was directly related to the perceived intensity of Agent Orange exposure.

PATIENT-SPECIFIC FINITE ELEMENT ANALYSIS OF CHRONIC CONTACT STRESS EXPOSURE AFTER INTRA-ARTICULAR FRACTURE OF THE TIBIAL PLAFOND

PubMed Central

Li, Wendy; Anderson, Donald D.; Goldsworthy, Jane K.; Marsh, J. Lawrence; Brown, Thomas D.

2008-01-01

SUMMARY The role of altered contact mechanics in the pathogenesis of post-traumatic osteoarthritis (PTOA) following intra-articular fracture remains poorly understood. One proposed etiology is that residual incongruities lead to altered joint contact stresses that, over time, predispose to PTOA. Prevailing joint contact stresses following surgical fracture reduction were quantified in this study using patient-specific contact finite element (FE) analysis. FE models were created for 11 ankle pairs from tibial plafond fracture patients. Both (reduced) fractured ankles and their intact contralaterals were modeled. A sequence of 13 loading instances was used to simulate the stance phase of gait. Contact stresses were summed across loadings in the simulation, weighted by resident time in the gait cycle. This chronic exposure measure, a metric of degeneration propensity, was then compared between intact and fractured ankle pairs. Intact ankles had lower peak contact stress exposures that were more uniform, and centrally located. The series-average peak contact stress elevation for fractured ankles was 38% (p=0.0015; peak elevation was 82%). Fractured ankles had less area with low contact stress exposure than intacts, and a greater area with high exposure. Chronic contact stress overexposures (stresses exceeding a damage threshold) ranged from near zero to a high of 18 times the matched intact value. The patient-specific FE models utilized in this study represent substantial progress towards elucidating the relationship between altered contact stresses and the outcome of patients treated for intra-articular fractures. PMID:18404662

Comparative MicroRNA Expression Patterns in Fibroblasts after Low and High Doses of Low-LET Radiation Exposure

NASA Technical Reports Server (NTRS)

Maes, Olivier C.; Xu, Suying; Hada, Megumi; Wu, Honglu; Wang, Eugenia

2007-01-01

Exposure to ionizing radiation causes DNA damage to cells, and provokes a plethora of cellular responses controlled by unique gene-directed signaling pathways. MicroRNAs (miRNAs) are small (22-nucleotide), non-coding RNAs which functionally silence gene expression by either degrading the messages or inhibiting translation. Here we investigate radiation-dependent changes in these negative regulators by comparing the expression patterns of all 462 known human miRNAs in fibroblasts, after exposure to low (0.1 Gy) or high (2 Gy) doses of X-rays at 30 min, 2, 6 and 24 hrs post-treatment. The expression patterns of microRNAs after low and high doses of radiation show a similar qualitative down-regulation trend at early (0.5 hr) and late (24 hr) time points, with a quantitatively steeper slope following the 2 Gy exposures. Interestingly, an interruption of this downward trend is observed after the 2 Gy exposure, i.e. a significant up-regulation of microRNAs at 2 hrs, then reverting to the downward trend by 6 hrs; this interruption at the intermediate time point was not observed with the 0.1 Gy exposure. At the early time point (0.5 hr), candidate gene targets of selected down-regulated microRNAs, common to both 0.1 and 2 Gy exposures, were those functioning in chromatin remodeling. Candidate target genes of unique up-regulated microRNAs seen at a 2 hr intermediate time point, after the 2 Gy exposure only, are those involved in cell death signaling. Finally, putative target genes of down-regulated microRNAs seen at the late (24 hr) time point after either doses of radiation are those involved in the up-regulation of DNA repair, cell signaling and homeostasis. Thus we hypothesize that after radiation exposure, microRNAs acting as hub negative regulators for unique signaling pathways needed to be down-regulated so as to de-repress their target genes for the proper cellular responses, including DNA repair and cell maintenance. The unique microRNAs up-regulated at 2 hr after 2

Pet exposure and risk of atopic dermatitis at the pediatric age: a meta-analysis of birth cohort studies.

PubMed

Pelucchi, Claudio; Galeone, Carlotta; Bach, Jean-François; La Vecchia, Carlo; Chatenoud, Liliane

2013-09-01

Findings on pet exposure and the risk of atopic dermatitis (AD) in children are inconsistent. With the aim to summarize the results of exposure to different pets on AD, we undertook a meta-analysis of epidemiologic studies on this issue. In August 2012, we conducted a systematic literature search in Medline and Embase. We included analytic studies considering exposure to dogs, cats, other pets, or pets overall during pregnancy, infancy, and/or childhood, with AD assessment performed during infancy or childhood. We calculated summary relative risks and 95% CIs using both fixed- and random-effects models. We computed summary estimates across selected subgroups. Twenty-six publications from 21 birth cohort studies were used in the meta-analyses. The pooled relative risks of AD for exposure versus no exposure were 0.72 (95% CI, 0.61-0.85; I(2) = 46%; results based on 15 studies) for exposure to dogs, 0.94 (95% CI, 0.76-1.16; I(2) = 54%; results based on 13 studies) for exposure to cats, and 0.75 (95% CI, 0.67-0.85; I(2) = 54%; results based on 11 studies) for exposure to pets overall. No heterogeneity emerged across the subgroups examined, except for geographic area. This meta-analysis reported a favorable effect of exposure to dogs and pets on the risk of AD in infants or children, whereas no association emerged with exposure to cats. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Antibiotic Exposure in Early Life Increases Risk of Childhood Obesity: A Systematic Review and Meta-Analysis

PubMed Central

Shao, Xiaoqing; Ding, Xiaolian; Wang, Bin; Li, Ling; An, Xiaofei; Yao, Qiuming; Song, Ronghua; Zhang, Jin-an

2017-01-01

A number of studies have previously assessed the impact of antibiotic exposure in early life on the risk of childhood obesity, but no systematic assessment is currently available. A systematic review and meta-analysis was performed to comprehensively and quantitatively elucidate the risk of childhood obesity caused by antibiotic exposure in early life. Literature search was performed in PubMed, Embase, and Web of Science. Random-effect meta-analysis was used to pool the statistical estimates. Fifteen cohort studies involving 445,880 participants were finally included, and all those studies were performed in developed countries. Antibiotic exposure in early life significantly increased risk of childhood overweight [relative risk (RR) = 1.23, 95% confidence interval (CI) 1.13–1.35, P < 0.001] and childhood obesity (RR = 1.21, 95% CI 1.13–1.30, P < 0.001). Antibiotic exposure in early life also significantly increased the z-score of childhood body mass index (mean difference: 0.07, 95% CI 0.05–0.09, P < 0.00001). Importantly, there was an obvious dose–response relationship between antibiotic exposure in early life and childhood adiposity, with a 7% increment in the risk of overweight (RR = 1.07, 95% CI 1.01–1.15, P = 0.03) and a 6% increment in the risk of obesity (RR = 1.06, 95% CI 1.02–1.09, P < 0.001) for each additional course of antibiotic exposure. In conclusion, antibiotic exposure in early life significantly increases risk of childhood obesity. Moreover, current analyses are mainly taken from developed countries, and therefore the impact of antibiotic exposure on risk of childhood obesity in vulnerable populations or developing countries still needs to be evaluated in future studies. PMID:28775712

Prenatal exposure to polychlorinated biphenyls: a neuropsychologic analysis.

PubMed

Boucher, Olivier; Muckle, Gina; Bastien, Célyne H

2009-01-01

A large body of literature documents the effects of prenatal exposure to polychlorinated biphenyls (PCBs) on cognitive development of children. Despite this fact, no integrative synthesis has been published yet to identify the cognitive functions that are particularly affected. Our aim is to review this literature in an attempt to identify the cognitive profile associated with prenatal PCB exposure. Studies were identified by searching the PubMed database for articles published before June 2008. We reviewed data from nine prospective longitudinal birth cohorts for different aspects of cognition. Associations between indicators of prenatal PCB exposure and performance on cognitive tasks reported in the selected studies are summarized and classified as general cognitive abilities, verbal or visual-spatial skills, memory, attention, and executive functions. The most consistent effects observed across studies are impaired executive functioning related to increased prenatal PCB exposure. Negative effects on processing speed, verbal abilities, and visual recognition memory are also reported by most studies. Converging results from different cohort studies in which exposure arises from different sources make it unlikely that co-exposure with another associated contaminant is responsible for the observed effects. Prenatal PCB exposure appears to be related to a relatively specific cognitive profile of impairments. Failure to assess functions that are specifically impaired may explain the absence of effects found in some studies. Our findings have implications in the selection of cognitive assessment methods in future studies.

Exposure to organochlorine pesticides and non-Hodgkin lymphoma: a meta-analysis of observational studies

PubMed Central

Luo, Dan; Zhou, Tingting; Tao, Yun; Feng, Yaqian; Shen, Xiaoli; Mei, Surong

2016-01-01

Growing evidence indicates that exposure to organochlorine pesticides (OCPs) could increase non-Hodgkin lymphoma (NHL) risk. However, results from epidemiological studies investigating this association remain controversial. We thus conducted a meta-analysis to quantitatively evaluate the association between OCP exposure and NHL risk. Relevant publications were searched in PubMed, Web of Science, and Embase and identified according to the inclusion criteria. Thirteen studies (6 nested case-control, 1 case-cohort, and 6 case-control) were selected for this meta-analysis. We used odds ratios (ORs) with 95% confidence intervals (CIs) to estimate the relationship between OCPs exposure and NHL risk. The summary OR for included studies was 1.40 (95% CI 1.27 to 1.56). No overall significant heterogeneity in the OR was observed (Ph = 0.253, I2 = 12.6%). Furthermore, OR estimates in subgroup analyses were discussed, and strong associations were observed for dichlorodiphenyldichloroethylene (DDE, OR = 1.38, 95% CI 1.14 to 1.66), hexachlorocyclohexane (HCH, OR = 1.42, 95% CI 1.08 to 1.87), chlordane (OR = 1.93, 95% CI 1.51 to 2.48), and hexachlorobenzene (HCB, OR = 1.54, 95% CI 1.20 to 1.99). This meta-analysis had suggested that total OCPs of interest was significantly positively associated with NHL risk. PMID:27185567

GENOMIC ANALYSIS OF SURROGATE TISSUES FOR ASSESSING ENVIRONMENTAL EXPOSURES AND FUTURE DISEASE STATES

EPA Science Inventory

Genomic Analysis of Surrogate Tissues for Assessing Environmental Exposures and Future Disease States

John C. Rockett, Chad R. Blystone, Amber K. Goetz, Rachel N. Murrell, Hongzu Ren, Judith E. Schmid, Jessica Stapelfeldt, Lillian F. Strader, Kary E. Thompson, Douglas B. T...

A model to systematically employ professional judgment in the Bayesian Decision Analysis for a semiconductor industry exposure assessment.

PubMed

Torres, Craig; Jones, Rachael; Boelter, Fred; Poole, James; Dell, Linda; Harper, Paul

2014-01-01

Bayesian Decision Analysis (BDA) uses Bayesian statistics to integrate multiple types of exposure information and classify exposures within the exposure rating categorization scheme promoted in American Industrial Hygiene Association (AIHA) publications. Prior distributions for BDA may be developed from existing monitoring data, mathematical models, or professional judgment. Professional judgments may misclassify exposures. We suggest that a structured qualitative risk assessment (QLRA) method can provide consistency and transparency in professional judgments. In this analysis, we use a structured QLRA method to define prior distributions (priors) for BDA. We applied this approach at three semiconductor facilities in South Korea, and present an evaluation of the performance of structured QLRA for determination of priors, and an evaluation of occupational exposures using BDA. Specifically, the structured QLRA was applied to chemical agents in similar exposure groups to identify provisional risk ratings. Standard priors were developed for each risk rating before review of historical monitoring data. Newly collected monitoring data were used to update priors informed by QLRA or historical monitoring data, and determine the posterior distribution. Exposure ratings were defined by the rating category with the highest probability--i.e., the most likely. We found the most likely exposure rating in the QLRA-informed priors to be consistent with historical and newly collected monitoring data, and the posterior exposure ratings developed with QLRA-informed priors to be equal to or greater than those developed with data-informed priors in 94% of comparisons. Overall, exposures at these facilities are consistent with well-controlled work environments. That is, the 95th percentile of exposure distributions are ≤50% of the occupational exposure limit (OEL) for all chemical-SEG combinations evaluated; and are ≤10% of the limit for 94% of chemical-SEG combinations evaluated.

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

ERIC Educational Resources Information Center

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

2013-01-01

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

Comparative Genome Analysis of Ciprofloxacin-Resistant Pseudomonas aeruginosa Reveals Genes Within Newly Identified High Variability Regions Associated With Drug Resistance Development

PubMed Central

Su, Hsun-Cheng; Khatun, Jainab; Kanavy, Dona M.

2013-01-01

The alarming rise of ciprofloxacin-resistant Pseudomonas aeruginosa has been reported in several clinical studies. Though the mutation of resistance genes and their role in drug resistance has been researched, the process by which the bacterium acquires high-level resistance is still not well understood. How does the genomic evolution of P. aeruginosa affect resistance development? Could the exposure of antibiotics to the bacteria enrich genomic variants that lead to the development of resistance, and if so, how are these variants distributed through the genome? To answer these questions, we performed 454 pyrosequencing and a whole genome analysis both before and after exposure to ciprofloxacin. The comparative sequence data revealed 93 unique resistance strain variation sites, which included a mutation in the DNA gyrase subunit A gene. We generated variation-distribution maps comparing the wild and resistant types, and isolated 19 candidates from three discrete resistance-associated high variability regions that had available transposon mutants, to perform a ciprofloxacin exposure assay. Of these region candidates with transposon disruptions, 79% (15/19) showed a reduction in the ability to gain high-level resistance, suggesting that genes within these high variability regions might enrich for certain functions associated with resistance development. PMID:23808957

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

PubMed

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

2010-01-01

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

Immunotoxicity and biodistribution analysis of arsenic trioxide in C57Bl/6 mice following a 2-week inhalation exposure

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

Burchiel, Scott W., E-mail: Sburchiel@salud.unm.ed; Mitchell, Leah A.; Lauer, Fredine T.

2009-12-15

In these studies the immunotoxicity of arsenic trioxide (ATO, As{sub 2}O{sub 3}) was evaluated in mice following 14 days of inhalation exposures (nose only, 3 h per day) at concentrations of 50 mug/m{sup 3} and 1 mg/m{sup 3}. A biodistribution analysis performed immediately after inhalation exposures revealed highest levels of arsenic in the kidneys, bladder, liver, and lung. Spleen cell levels were comparable to those found in the blood, with the highest concentration of arsenic detected in the spleen being 150 mug/g tissue following the 1 mg/m{sup 3} exposures. No spleen cell cytotoxicity was observed at either of the twomore » exposure levels. There were no changes in spleen cell surface marker expression for B cells, T cells, macrophages, and natural killer (NK) cells. There were also no changes detected in the B cell (LPS-stimulated) and T cell (Con A-stimulated) proliferative responses of spleen cells, and no changes were found in the NK-mediated lysis of Yac-1 target cells. The primary T-dependent antibody response was, however, found to be highly susceptible to ATO suppression. Both the 50 mug/m{sup 3} and 1 mg/m{sup 3} exposures produced greater than 70% suppression of the humoral immune response to sheep red blood cells. Thus, the primary finding of this study is that the T-dependent humoral immune response is extremely sensitive to suppression by ATO and assessment of humoral immune responses should be considered in evaluating the health effects of arsenic containing agents.« less

Biological monitoring of smoke exposure among wildland firefighters: Apilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2009-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest Service Savannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relatingmore » changes in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small

Biological monitoring of smoke exposure among wildland firefighters: Apilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2009-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest ServiceFSavannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relating changesmore » in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small

Biological monitoring of smoke exposure among wildland firefighters: Apilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2008-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest Service Savannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relatingmore » changes in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small

Occupational exposures and pancreatic cancer: a meta-analysis

PubMed Central

Ojajarvi, I; Partanen, T.; Ahlbom, A.; Boffetta, P.; Hakulinen, T.; Jourenkova, N.; Kauppinen, T.; Kogevinas, M.; Porta, M.; Vainio, H.; Weiderpass, E.; Wesseling, C.

2000-01-01

insecticides, 33%; and to PAHs, 33%.
CONCLUSION—Occupational exposures may increase risk of pancreatic cancer. High quality studies are called for on interactions between occupational, environmental, and lifestyle factors as well as interactions between genes and the environment.


Keywords: pancreatic cancer; occupational exposure; meta-analysis PMID:10769297

Comparative transcriptomics reveals genes involved in metabolic and immune pathways in the digestive gland of scallop Chlamys farreri following cadmium exposure

NASA Astrophysics Data System (ADS)

Zhang, Hui; Zhai, Yuxiu; Yao, Lin; Jiang, Yanhua; Li, Fengling

2017-05-01

Chlamys farreri is an economically important mollusk that can accumulate excessive amounts of cadmium (Cd). Studying the molecular mechanism of Cd accumulation in bivalves is difficult because of the lack of genome background. Transcriptomic analysis based on high-throughput RNA sequencing has been shown to be an efficient and powerful method for the discovery of relevant genes in non-model and genome reference-free organisms. Here, we constructed two cDNA libraries (control and Cd exposure groups) from the digestive gland of C. farreri and compared the transcriptomic data between them. A total of 227 673 transcripts were assembled into 105 071 unigenes, most of which shared high similarity with sequences in the NCBI non-redundant protein database. For functional classification, 24 493 unigenes were assigned to Gene Ontology terms. Additionally, EuKaryotic Ortholog Groups and Kyoto Encyclopedia of Genes and Genomes analyses assigned 12 028 unigenes to 26 categories and 7 849 unigenes to five pathways, respectively. Comparative transcriptomics analysis identified 3 800 unigenes that were differentially expressed in the Cd-treated group compared with the control group. Among them, genes associated with heavy metal accumulation were screened, including metallothionein, divalent metal transporter, and metal tolerance protein. The functional genes and predicted pathways identified in our study will contribute to a better understanding of the metabolic and immune system in the digestive gland of C. farreri. In addition, the transcriptomic data will provide a comprehensive resource that may contribute to the understanding of molecular mechanisms that respond to marine pollutants in bivalves.

Temporal observations of bright soil exposures at Gusev crater, Mars

USGS Publications Warehouse

Rice, M.S.; Bell, J.F.; Cloutis, E.A.; Wray, J.J.; Herkenhoff, K. E.; Sullivan, R.; Johnson, J. R.; Anderson, R.B.

2011-01-01

The Mars Exploration Rover Spirit has discovered bright soil deposits in its wheel tracks that previously have been confirmed to contain ferric sulfates and/or opaline silica. Repeated Pancam multispectral observations have been acquired at four of these deposits to monitor spectral and textural changes over time during exposure to Martian surface conditions. Previous studies suggested that temporal spectral changes occur because of mineralogic changes (e.g., phase transitions accompanying dehydration). In this study, we present a multispectral and temporal analysis of eight Pancam image sequences at the Tyrone exposure, three at the Gertrude Weise exposure, two at the Kit Carson exposure, and ten at the Ulysses exposure that have been acquired as of sol 2132 (1 January 2010). We compare observed variations in Pancam data to spectral changes predicted by laboratory experiments for the dehydration of ferric sulfates. We also present a spectral analysis of repeated Mars Reconnaissance Orbiter HiRISE observations spanning 32 sols and a textural analysis of Spirit Microscopic Imager observations of Ulysses spanning 102 sols. At all bright soil exposures, we observe no statistically significant spectral changes with time that are uniquely diagnostic of dehydration and/or mineralogic phase changes. However, at Kit Carson and Ulysses, we observe significant textural changes, including slumping within the wheel trench, movement of individual grains, disappearance of fines, and dispersal of soil clods. All observed textural changes are consistent with aeolian sorting and/or minor amounts of air fall dust deposition.

Cadmium exposure and risk of pancreatic cancer: A meta-analysis of prospective cohort studies and case-control studies among individuals without occupational exposure history

PubMed Central

Chen, Cheng; Xun, Pengcheng; Nishijo, Muneko; Sekikawa, Akira

2015-01-01

Pancreatic cancer is one of the most deadly types of cancer for both genders. Classified as a human carcinogen, cadmium has been related to diverse cancers. However, the association between cadmium exposure and the risk of pancreatic cancer is still unclear. We quantitatively reviewed the observational studies on the association of cadmium exposure with pancreatic cancer risk among individuals without occupational exposure history published through July 2014 in PubMed by using a fixed–effects model. Four prospective cohort studies (112,934 participants with 335 events) and two case-control studies (177 cases and 539 controls) were identified. The summarized relative risk (RR) with a 95% confidence interval (CI) was 2.05 (95% CI=1.58 – 2.66), comparing the highest to the lowest category of cadmium exposure. This positive association persisted in men (RR=1.78; 95% CI=1.04 – 3.05), but not in women (RR=1.02; 95% CI=0.63 – 1.65). Further research is needed to provide more solid evidence on the association of cadmium exposure with pancreatic cancer risk and to elucidate the underlying biological mechanism of the potential gender difference. PMID:26423282

Cadmium exposure and risk of pancreatic cancer: a meta-analysis of prospective cohort studies and case-control studies among individuals without occupational exposure history.

PubMed

Chen, Cheng; Xun, Pengcheng; Nishijo, Muneko; Sekikawa, Akira; He, Ka

2015-11-01

Pancreatic cancer is one of the most deadly types of cancer for both genders. Classified as a human carcinogen, cadmium has been related to diverse cancers. However, the association between cadmium exposure and the risk of pancreatic cancer is still unclear. We quantitatively reviewed the observational studies on the association of cadmium exposure with pancreatic cancer risk among individuals without occupational exposure history published through July 2014 in PubMed by using a fixed-effect model. Four prospective cohort studies (112,934 participants with 335 events) and two case-control studies (177 cases and 539 controls) were identified. The summarized relative risk (RR) with a 95% confidence interval (CI) was 2.05 (95% CI = 1.58-2.66), comparing the highest to the lowest category of cadmium exposure. This positive association persisted in men (RR = 1.78, 95% CI = 1.04-3.05) but not in women (RR = 1.02, 95% CI = 0.63-1.65). Further research is needed to provide more solid evidence on the association of cadmium exposure with pancreatic cancer risk and to elucidate the underlying biological mechanism of the potential gender difference.

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

PubMed

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

2012-10-01

A new head exposure system for double-blind provocation studies investigating possible effects of terrestrial trunked radio (TETRA)-like exposure (385 MHz) on central nervous processes was developed and dosimetrically analyzed. The exposure system allows localized exposure in the temporal brain, similar to the case of operating a TETRA handset at the ear. The system and antenna concept enables exposure during wake and sleep states while an electroencephalogram (EEG) is recorded. The dosimetric assessment and uncertainty analysis yield high efficiency of 14 W/kg per Watt of accepted antenna input power due to an optimized antenna directly worn on the subject's head. Beside sham exposure, high and low exposure at 6 and 1.5 W/kg (in terms of maxSAR10g in the head) were implemented. Double-blind control and monitoring of exposure is enabled by easy-to-use control software. Exposure uncertainty was rigorously evaluated using finite-difference time-domain (FDTD)-based computations, taking into account anatomical differences of the head, the physiological range of the dielectric tissue properties including effects of sweating on the antenna, possible influences of the EEG electrodes and cables, variations in antenna input reflection coefficients, and effects on the specific absorption rate (SAR) distribution due to unavoidable small variations in the antenna position. This analysis yielded a reasonable uncertainty of <±45% (max to min ratio of 4.2 dB) in terms of maxSAR10g in the head and a variability of <±60% (max to min ratio of 6 dB) in terms of mass-averaged SAR in different brain regions, as demonstrated by a brain region-specific absorption analysis. Copyright © 2012 Wiley Periodicals, Inc.

Evaluation of the Tobacco Heating System 2.2. Part 4: 90-day OECD 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects compared with cigarette smoke.

PubMed

Wong, Ee Tsin; Kogel, Ulrike; Veljkovic, Emilija; Martin, Florian; Xiang, Yang; Boue, Stephanie; Vuillaume, Gregory; Leroy, Patrice; Guedj, Emmanuel; Rodrigo, Gregory; Ivanov, Nikolai V; Hoeng, Julia; Peitsch, Manuel C; Vanscheeuwijck, Patrick

2016-11-30

The objective of the study was to characterize the toxicity from sub-chronic inhalation of test atmospheres from the candidate modified risk tobacco product (MRTP), Tobacco Heating System version 2.2 (THS2.2), and to compare it with that of the 3R4F reference cigarette. A 90-day nose-only inhalation study on Sprague-Dawley rats was performed, combining classical and systems toxicology approaches. Reduction in respiratory minute volume, degree of lung inflammation, and histopathological findings in the respiratory tract organs were significantly less pronounced in THS2.2-exposed groups compared with 3R4F-exposed groups. Transcriptomics data obtained from nasal epithelium and lung parenchyma showed concentration-dependent differential gene expression following 3R4F exposure that was less pronounced in the THS2.2-exposed groups. Molecular network analysis showed that inflammatory processes were the most affected by 3R4F, while the extent of THS2.2 impact was much lower. Most other toxicological endpoints evaluated did not show exposure-related effects. Where findings were observed, the effects were similar in 3R4F- and THS2.2-exposed animals. In summary, toxicological changes observed in the respiratory tract organs of THS2.2 aerosol-exposed rats were much less pronounced than in 3R4F-exposed rats while other toxicological endpoints either showed no exposure-related effects or were comparable to what was observed in the 3R4F-exposed rats. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Nanoparticle exposure biomonitoring: exposure/effect indicator development approaches

NASA Astrophysics Data System (ADS)

Marie-Desvergne, C.; Dubosson, M.; Lacombe, M.; Brun, V.; Mossuz, V.

2015-05-01

The use of engineered nanoparticles (NP) is more and more widespread in various industrial sectors. The inhalation route of exposure is a matter of concern (adverse effects of air pollution by ultrafine particles and asbestos). No NP biomonitoring recommendations or standards are available so far. The LBM laboratory is currently studying several approaches to develop bioindicators for occupational health applications. As regards exposure indicators, new tools are being implemented to assess potentially inhaled NP in non-invasive respiratory sampling (nasal sampling and exhaled breath condensates (EBC)). Diverse NP analytical characterization methods are used (ICP-MS, dynamic light scattering and electron microscopy coupled to energy-dispersive X-ray analysis). As regards effect indicators, a methodology has been developed to assess a range of 29 cytokines in EBCs (potential respiratory inflammation due to NP exposure). Secondly, collaboration between the LBM laboratory and the EDyp team has allowed the EBC proteome to be characterized by means of an LC-MS/MS process. These projects are expected to facilitate the development of individual NP exposure biomonitoring tools and the analysis of early potential impacts on health. Innovative techniques such as field-flow fractionation combined with ICP-MS and single particle-ICPMS are currently being explored. These tools are directly intended to assist occupational physicians in the identification of exposure situations.

Self-reported and laboratory evaluation of late pregnancy nicotine exposure and drugs of abuse.

PubMed

Hall, E S; Wexelblatt, S L; Greenberg, J M

2016-10-01

The objective of this study was to evaluate the prevalence of late pregnancy nicotine exposures, including secondhand smoke exposures, and to evaluate the associated risk of exposure to drugs of abuse. The study was a retrospective single-center cohort analysis of more than 18 months. We compared self-reported smoking status from vital birth records with mass spectrometry laboratory results of maternal urine using a chi-square test. Logistic regression estimated adjusted odds for detection of drugs of abuse based on nicotine detection. Compared with 8.6% self-reporting cigarette use, mass spectrometry detected high-level nicotine exposures for 16.5% of 708 women (P<0.001) and an additional 7.5% with low-level exposures. We identified an increased likelihood of exposure to drugs of abuse, presented as adjusted odds ratios, (95% confidence interval (CI), for both low-level (5.69, CI: 2.09 to 15.46) and high-level (13.93, CI: 7.06 to 27.49) nicotine exposures. Improved measurement tactics are critically needed to capture late pregnancy primary and passive nicotine exposures from all potential sources.

Risk analysis for worker exposure to benzene

NASA Astrophysics Data System (ADS)

Hallenbeck, William H.; Flowers, Roxanne E.

1992-05-01

Cancer risk factors (characterized by route, dose, dose rate per kilogram, fraction of lifetime exposed, species, and sex) were derived for workers exposed to benzene via inhalation or ingestion. Exposure at the current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) and at leaking underground storage tank (LUST) sites were evaluated. At the current PEL of 1 ppm, the theoretical lifetime excess risk of cancer from benzene inhalation is ten per 1000. The theoretical lifetime excess risk for worker inhalation exposure at LUST sites ranged from 10 to 40 per 1000. These results indicate that personal protection should be required. The theoretical lifetime excess risk due to soil ingestion is five to seven orders of magnitude less than the inhalation risks.

Analysis and testing of Koornstra-type induced exposure models

DOT National Transportation Integrated Search

1985-10-01

Induced exposure models postulate a structure for accident data which permits the : estimation of two factors: exposure and proneness. Since information on exposure : is needed in order to assess the accident risk of different driver, vehicle, and : ...

Exposure to psychosocial work factors in 31 European countries.

PubMed

Niedhammer, I; Sultan-Taïeb, H; Chastang, J-F; Vermeylen, G; Parent-Thirion, A

2012-04-01

Although psychosocial work factors are recognized as major occupational risk factors, little information is available regarding the prevalence of exposure to these factors and the differences in exposure between countries. To explore the differences in various psychosocial work exposures between 31 European countries. The study was based on a sample of 14,881 male and 14,799 female workers from the 2005 European Working Conditions Survey. Eighteen psychosocial work factors were studied: low decision latitude (skill discretion and decision authority), high psychological demands, job strain, low social support, iso-strain, physical violence, sexual harassment, bullying, discrimination, work-family imbalance, long working hours, high effort, job insecurity, low job promotion, low reward and effort-reward imbalance. Covariates were age, number of workers in household, occupation, economic activity, self-employed/employee, public/private sector and part/full time work. Statistical analysis was performed using multilevel logistic regression analysis. Significant differences in all psychosocial work factors were observed between countries. The rank of the countries varied according to the exposure considered. However, some countries, especially Denmark, Netherlands and Norway, displayed a significantly lower prevalence of exposure to four factors or more, while some Southern and Eastern countries, especially Czech Republic, Greece, Lithuania and Turkey, had a higher prevalence. Differences in psychosocial work exposures were found between countries. This study is the first to compare a large set of psychosocial work exposures between 31 European countries. These findings may be useful to guide prevention policies at European level.

Association between occupational exposure to benzene and chromosomal alterations in lymphocytes of Brazilian petrochemical workers removed from exposure.

PubMed

Gonçalves, Rozana Oliveira; de Almeida Melo, Neli; Rêgo, Marco Antônio Vasconcelos

2016-06-01

We aimed to investigate the association between chronic exposure to benzene and genotoxicity in the lymphocytes of workers removed from exposure. The study included 20 workers with hematological disorders who had previously worked in the petrochemical industry of Salvador, Bahia, Brazil; 16 workers without occupational exposure to benzene served as the control group. Chromosomal analysis was performed on lymphocytes from peripheral blood, to assess chromosomal breaks and gaps and to identify aneuploidy. The Kruskal-Wallis test was used to compare the mean values between two groups, and Student's t test for comparison of two independent means. The frequency of gaps was statistically higher in and the exposed group than in the controls (2.13 ± 2.86 vs. 0.97 ± 1.27, p = 0.001). The frequency of chromosomal breaks was significantly higher among cases (0.21 ± 0.58) than among controls (0.12 ± 0.4) (p = 0.0002). An association was observed between chromosomal gaps and breaks and occupational exposure to benzene. Our study showed that even when removed from exposure for several years, workers still demonstrated genotoxic damage. Studies are still needed to clarify the long-term genotoxic potential of benzene after removal from exposure.

Tetrachloroethylene Exposure and Bladder Cancer Risk: A Meta-Analysis of Dry-Cleaning-Worker Studies

PubMed Central

Vlaanderen, Jelle; Straif, Kurt; Ruder, Avima; Blair, Aaron; Hansen, Johnni; Lynge, Elsebeth; Charbotel, Barbara; Loomis, Dana; Kauppinen, Timo; Kyyronen, Pentti; Pukkala, Eero; Weiderpass, Elisabete

2014-01-01

Background: In 2012, the International Agency for Research on Cancer classified tetrachloroethylene, used in the production of chemicals and the primary solvent used in dry cleaning, as “probably carcinogenic to humans” based on limited evidence of an increased risk of bladder cancer in dry cleaners. Objectives: We assessed the epidemiological evidence for the association between tetrachloroethylene exposure and bladder cancer from published studies estimating occupational exposure to tetrachloroethylene or in workers in the dry-cleaning industry. Methods: Random-effects meta-analyses were carried out separately for occupational exposure to tetrachloroethylene and employment as a dry cleaner. We qualitatively summarized exposure–response data because of the limited number of studies available. Results: The meta-relative risk (mRR) among tetrachloroethylene-exposed workers was 1.08 (95% CI: 0.82, 1.42; three studies; 463 exposed cases). For employment as a dry cleaner, the overall mRR was 1.47 (95% CI: 1.16, 1.85; seven studies; 139 exposed cases), and for smoking-adjusted studies, the mRR was 1.50 (95% CI: 0.80, 2.84; 4 case–control studies). Conclusions: Our meta-analysis demonstrates an increased risk of bladder cancer in dry cleaners, reported in both cohort and case–control studies, and some evidence for an exposure–response relationship. Although dry cleaners incur mixed exposures, tetrachloroethylene could be responsible for the excess risk of bladder cancer because it is the primary solvent used and it is the only chemical commonly used by dry cleaners that is currently identified as a potential bladder carcinogen. Relatively crude approaches in exposure assessment in the studies of “tetrachloroethylene-exposed workers” may have attenuated the relative risks. Citation: Vlaanderen J, Straif K, Ruder A, Blair A, Hansen J, Lynge E, Charbotel B, Loomis D, Kauppinen T, Kyyronen P, Pukkala E, Weiderpass E, Guha N. 2014. Tetrachloroethylene exposure

Occupational styrene exposure and acquired dyschromatopsia: A systematic review and meta-analysis.

PubMed

Choi, Ariel R; Braun, Joseph M; Papandonatos, George D; Greenberg, Paul B

2017-11-01

Styrene is a chemical used in the manufacture of plastic-based products worldwide. We systematically reviewed eligible studies of occupational styrene-induced dyschromatopsia, qualitatively synthesizing their findings and estimating the exposure effect through meta-analysis. PubMed, EMBASE, and Web of Science databases were queried for eligible studies. Using a random effects model, we compared measures of dyschromatopsia between exposed and non-exposed workers to calculate the standardized mean difference (Hedges'g). We also assessed between-study heterogeneity and publication bias. Styrene-exposed subjects demonstrated poorer color vision than did the non-exposed (Hedges' g = 0.56; 95%CI: 0.37, 0.76; P < 0.0001). A non-significant Cochran's Q test result (Q = 23.2; P = 0.171) and an I 2 of 32.2% (0.0%, 69.9%) indicated low-to-moderate between-study heterogeneity. Funnel plot and trim-and-fill analyses suggested publication bias. This review confirms the hypothesis of occupational styrene-induced dyschromatopsia, suggesting a modest effect size with mild heterogeneity between studies. © 2017 Wiley Periodicals, Inc.

A Meta-Analysis of Children's Object-to-Mouth Frequency Data for Estimating Non-Dietary Ingestion Exposure

EPA Science Inventory

To improve estimates of non-dietary ingestion in probabilistic exposure modeling, a meta-analysis of children's object-to-mouth frequency was conducted using data from seven available studies representing 438 participants and ~ 1500 h of behavior observation. The analysis repres...

Risk of breast cancer following exposure to tetrachloroethylene-contaminated drinking water in Cape Cod, Massachusetts: reanalysis of a case-control study using a modified exposure assessment

PubMed Central

2011-01-01

Background Tetrachloroethylene (PCE) is an important occupational chemical used in metal degreasing and drycleaning and a prevalent drinking water contaminant. Exposure often occurs with other chemicals but it occurred alone in a pattern that reduced the likelihood of confounding in a unique scenario on Cape Cod, Massachusetts. We previously found a small to moderate increased risk of breast cancer among women with the highest exposures using a simple exposure model. We have taken advantage of technical improvements in publically available software to incorporate a more sophisticated determination of water flow and direction to see if previous results were robust to more accurate exposure assessment. Methods The current analysis used PCE exposure estimates generated with the addition of water distribution modeling software (EPANET 2.0) to test model assumptions, compare exposure distributions to prior methods, and re-examine the risk of breast cancer. In addition, we applied data smoothing to examine nonlinear relationships between breast cancer and exposure. We also compared a set of measured PCE concentrations in water samples collected in 1980 to modeled estimates. Results Thirty-nine percent of individuals considered unexposed in prior epidemiological analyses were considered exposed using the current method, but mostly at low exposure levels. As a result, the exposure distribution was shifted downward resulting in a lower value for the 90th percentile, the definition of "high exposure" in prior analyses. The current analyses confirmed a modest increase in the risk of breast cancer for women with high PCE exposure levels defined by either the 90th percentile (adjusted ORs 1.0-1.5 for 0-19 year latency assumptions) or smoothing analysis cut point (adjusted ORs 1.3-2.0 for 0-15 year latency assumptions). Current exposure estimates had a higher correlation with PCE concentrations in water samples (Spearman correlation coefficient = 0.65, p < 0.0001) than estimates

Exposure to violent video games and aggression in German adolescents: a longitudinal analysis.

PubMed

Möller, Ingrid; Krahé, Barbara

2009-01-01

The relationship between exposure to violent electronic games and aggressive cognitions and behavior was examined in a longitudinal study. A total of 295 German adolescents completed the measures of violent video game usage, endorsement of aggressive norms, hostile attribution bias, and physical as well as indirect/relational aggression cross-sectionally, and a subsample of N=143 was measured again 30 months later. Cross-sectional results at T1 showed a direct relationship between violent game usage and aggressive norms, and an indirect link to hostile attribution bias through aggressive norms. In combination, exposure to game violence, normative beliefs, and hostile attribution bias predicted physical and indirect/relational aggression. Longitudinal analyses using path analysis showed that violence exposure at T1 predicted physical (but not indirect/relational) aggression 30 months later, whereas aggression at T1 was unrelated to later video game use. Exposure to violent games at T1 influenced physical (but not indirect/relational) aggression at T2 via an increase of aggressive norms and hostile attribution bias. The findings are discussed in relation to social-cognitive explanations of long-term effects of media violence on aggression. Copyright 2008 Wiley-Liss, Inc.

MetaComp: comprehensive analysis software for comparative meta-omics including comparative metagenomics.

PubMed

Zhai, Peng; Yang, Longshu; Guo, Xiao; Wang, Zhe; Guo, Jiangtao; Wang, Xiaoqi; Zhu, Huaiqiu

2017-10-02

During the past decade, the development of high throughput nucleic sequencing and mass spectrometry analysis techniques have enabled the characterization of microbial communities through metagenomics, metatranscriptomics, metaproteomics and metabolomics data. To reveal the diversity of microbial communities and interactions between living conditions and microbes, it is necessary to introduce comparative analysis based upon integration of all four types of data mentioned above. Comparative meta-omics, especially comparative metageomics, has been established as a routine process to highlight the significant differences in taxon composition and functional gene abundance among microbiota samples. Meanwhile, biologists are increasingly concerning about the correlations between meta-omics features and environmental factors, which may further decipher the adaptation strategy of a microbial community. We developed a graphical comprehensive analysis software named MetaComp comprising a series of statistical analysis approaches with visualized results for metagenomics and other meta-omics data comparison. This software is capable to read files generated by a variety of upstream programs. After data loading, analyses such as multivariate statistics, hypothesis testing of two-sample, multi-sample as well as two-group sample and a novel function-regression analysis of environmental factors are offered. Here, regression analysis regards meta-omic features as independent variable and environmental factors as dependent variables. Moreover, MetaComp is capable to automatically choose an appropriate two-group sample test based upon the traits of input abundance profiles. We further evaluate the performance of its choice, and exhibit applications for metagenomics, metaproteomics and metabolomics samples. MetaComp, an integrative software capable for applying to all meta-omics data, originally distills the influence of living environment on microbial community by regression analysis

Inhalation exposure and risk of polycyclic aromatic hydrocarbons (PAHs) among the rural population adopting wood gasifier stoves compared to different fuel-stove users

NASA Astrophysics Data System (ADS)

Lin, Nan; Chen, Yuanchen; Du, Wei; Shen, Guofeng; Zhu, Xi; Huang, Tianbo; Wang, Xilong; Cheng, Hefa; Liu, Junfeng; Xue, Chunyu; Liu, Guangqing; Zeng, Eddy Y.; Xing, Baoshan; Tao, Shu

2016-12-01

Polycyclic aromatica hydrocarbons (PAHs) are a group of compounds with carcinogenic potentials and residential solid fuel combustion is one major source of PAHs in most developing countries. Replacement of traditional stoves with improved ones is believed to be a practical approach to reduce pollutant emissions, however, field assessments on the performance and consequent impacts on air quality and human health after adopting improved stoves are rare. The study is the first time to quantify inhalation exposure to PAHs among the residents who adopted wood gasifier stoves. The results were compared to those still burning coals in the region and compared to exposure levels for different fuel/stove users in literature. The results showed that the PAHs exposure levels for the wood gasifier stove users were significantly lower than the values for those using traditional wood stoves reported in literature, and the daily exposure concentrations of BaPeq (Benzo[a]pyrene equivalent concentration) can be reduced by 48%-91% if traditional wood stoves were replaced by wood gasifier stoves. The corresponding Incremental Lifetime Cancer Risk (ILCR) decreased approximately four times from 1.94 × 10-4 to 5.17 × 10-5. The average concentration of the total 26 PAHs for the wood users was 1091 ± 722 ng/m3, which was comparable to 1060 ± 927 ng/m3 for those using anthracite coals, but the composition profiles were considerably different. The average BaPeq were 116 and 25.8 ng/m3 for the wood and coal users, respectively, and the corresponding ILCR of the anthracite coal users was 1.69 × 10-5, which was nearly one third of those using the wood gasifier stoves. The wood users exposed to not only high levels of high molecular weight PAHs, but relatively high fractions of particulate phase PAHs in small particles compared to the coal users, resulting in high exposure risks.

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

DTIC Science & Technology

2014-06-01

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

Haploid parthenotes express differential response to in vitro exposure of ammonia compared to normally fertilized embryos.

PubMed

Nair, Ramya; Mutalik, Srinivas; Dasappa, Jagadeesh Prasad; Kalthur, Guruprasad; Adiga, Satish Kumar

2017-04-22

In the present study, we assessed whether absence of paternal genome imparts any differential response in embryos to chemical stress such as ammonia. Parthenogenesis was induced in MII stage oocytes using 10 mM SrCl 2 in M16 medium. Parthenotes and normally fertilized embryos at 2 cell stage were exposed to different concentrations of ammonia and cultured till blastocyst. Exposure of ammonia to normally fertilized embryos resulted in significant decrease in the developmental potential (p < 0.0001) and blastocyst quality (p < 0.001). Whereas, in parthenotes, even though lower concentrations of ammonia did not have any effect, at 200 μM concentration the blastocyst rate was two times higher than control. The baseline apoptotic index was higher in parthenotes compared to normally fertilized embryos, which further increased after ammonium exposure (p < 0.001). Unlike in normally fertilized embryos ammonia exposure altered the mitochondrial distribution pattern and lead to increased expression of Oct4, Nanog and Na + /K + ion exchange channel, while the cytochrome C expression was downregulated. This indicates that haploidy and/or absence of paternal factors in the embryo results in differential tolerance to stress induced by ammonia. Copyright © 2017 Elsevier Inc. All rights reserved.

Compare ultrasound-mediated heating and cavitation between flowing polymer- and lipid-shelled microbubbles during focused ultrasound exposures.

PubMed

Zhang, Siyuan; Zong, Yujin; Wan, Mingxi; Yu, Xiaojun; Fu, Quanyou; Ding, Ting; Zhou, Fanyu; Wang, Supin

2012-06-01

This paper compares the efficiency of flowing polymer- and lipid-shelled microbubbles (MBs) in the heating and cavitation during focused ultrasound exposures. Temperature and cavitation activity were simultaneously measured as the two types of shelled MBs and saline flowing through a 3 mm diameter vessel in the phantom with varying flow velocities (0-20 cm/s) at different acoustic power levels (0.6-20 W) with each exposure for 5 s. Temperature and cavitation for the lipid-shelled MBs were higher than those for the polymer-shelled MBs. Temperature rise decreased with increasing flow velocities for the two types of shelled MBs and saline at acoustic power 1.5 W. At acoustic power 11.1 W, temperature rise increased with increasing flow velocities for the lipid-shelled MBs. For the polymer-shelled MBs, the temperature rise increased with increasing flow velocities from 3-15 cm/s and decreased at 20 cm/s. Cavitation increased with increasing flow velocity for the two shelled MBs and there were no significant changes of cavitation with increasing flow velocities for saline. These results suggested that lipid-shelled MBs may have a greater efficiency than polymer-shelled MBs in heating and cavitation during focused ultrasound exposures.

Isocyanate exposure and occupational asthma: a case-referent study

PubMed Central

Meredith, S; Bugler, J; Clark, R

2000-01-01

OBJECTIVE—To examine the quantitative relation between exposure to isocyanates and occupational asthma, and to explore the role of atopy and smoking in occurrence of the disease.
METHOD—A case-referent study was undertaken of cases from two manufacturing companies (A and B) from which referents without disease could be selected and reliable exposure measurements were available. In company A, 27 cases mainly attributed to toluene diisocyanate (TDI) were matched to 51 referents on work area, start and duration of employment, sex, and age. Exposures were estimated from existing measurements by job category. In company B there were seven cases attributed to 4,4'-diphenylmethane diisocyanate (MDI) in two areas of the plant; 12 non-cases from the same areas were used as referents. Personal exposure measurements were available for all cases and 11 referents.
RESULTS—No difference in peak exposures between cases and referents was found in either plant; but in both, time weighted average (TWA) exposures at the time of onset of asthma were higher for cases. In A, the mean TWA exposure for cases was 1.5 (95% confidence interval (95% CI) 1.2 to 1.8) ppb compared with 1.2 (1.0 to 1.4) ppb for referents. From a matched analysis, the odds ratio (OR) associated with 8 hour TWA exposure to isocyanates greater than 1.125 ppb (the median concentration for the referent group) was 3.2 (95% CI 0.96 to 10.6; p=0.06). Occupational asthma was associated with a pre-employment history of atopic illness (OR 3.5, p=0.04) and, less strongly, with smoking (OR 2.1, p=0.14). In B, small numbers limited analysis, but three of seven cases had at least one TWA exposure measurement greater than 5 ppb compared with one of 11 referents (OR 7.5, p=0.09).
CONCLUSION—Asthma can occur at low concentrations of isocyanates, but even at low concentrations, the higher the exposure the greater the risk. By contrast with other studies, smoking and atopy seemed to increase the odds

Comparative Proteomic Analysis of Light-Induced Mycelial Brown Film Formation in Lentinula edodes.

PubMed

Tang, Li Hua; Tan, Qi; Bao, Da Peng; Zhang, Xue Hong; Jian, Hua Hua; Li, Yan; Yang, Rui Heng; Wang, Ying

2016-01-01

Light-induced brown film (BF) formation by the vegetative mycelium of Lentinula edodes is important for ensuring the quantity and quality of this edible mushroom. Nevertheless, the molecular mechanism underlying this phenotype is still unclear. In this study, a comparative proteomic analysis of mycelial BF formation in L. edodes was performed. Seventy-three protein spots with at least a twofold difference in abundance on two-dimensional electrophoresis (2DE) maps were observed, and 52 of them were successfully identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF/MS). These proteins were classified into the following functional categories: small molecule metabolic processes (39%), response to oxidative stress (5%), and organic substance catabolic processes (5%), followed by oxidation-reduction processes (3%), single-organism catabolic processes (3%), positive regulation of protein complex assembly (3%), and protein metabolic processes (3%). Interestingly, four of the proteins that were upregulated in response to light exposure were nucleoside diphosphate kinases. To our knowledge, this is the first proteomic analysis of the mechanism of BF formation in L. edodes . Our data will provide a foundation for future detailed investigations of the proteins linked to BF formation.

Determinants of Exposure to Metalworking Fluid Aerosols: A Literature Review and Analysis of Reported Measurements

PubMed Central

Park, Donguk; Stewart, Patrica A.; Coble, Joseph B.

2009-01-01

An extensive literature review of published metalworking fluid (MWF) aerosol measurement data was conducted to identify the major determinants that may affect exposure to aerosol fractions (total or inhalable, thoracic and respirable) and mass median diameters (MMDs). The identification of determinants was conducted through published studies and analysis of published measurement levels. For the latter, weighted arithmetic means (WAMs) by number of measurements were calculated and compared using analysis of variance and t-tests. The literature review found that the major factors affecting aerosol exposure levels were, primarily, decade, type of industry, operation and fluid and engineering control measures. Our analysis of total aerosol levels found a significant decline in measured levels from an average of 5.36 mg m−3 prior to the 1970s and 2.52 mg m−3 in the 1970s to 1.21 mg m−3 in the 1980s, 0.50 mg m−3 in the 1990s and 0.55 mg m−3 in the 2000s. Significant declines from the 1990s to the 2000s also were found in thoracic fraction levels (0.48 versus 0.40 mg m−3), but not for the respirable fraction. The WAMs for the auto (1.47 mg m−3) and auto parts manufacturing industry (1.83 mg m−3) were significantly higher than that for small-job machine shops (0.68 mg m−3). In addition, a significant difference in the thoracic WAM was found between the automotive industry (0.46 mg m−3) and small-job machine shops (0.32 mg m−3). Operation type, in particular, grinding, was a significant factor affecting the total aerosol fraction [grinding operations (1.75 mg m−3) versus other machining (0.95 mg m−3)], but the levels associated with these operations were not statistically different for either the thoracic or the respirable fractions. Across all decades, the total aerosol fraction for straight oils (1.49 mg m−3) was higher than for other fluid types (soluble = 1.08 mg m−3, synthetic = 0.52 mg m−3 and semisynthetic = 0.50 mg m−3

GENOMIC AND PROTEOMIC ANALYSIS OF SURROGATE TISSUES FOR ASSESSING TOXIC EXPOSURES AND DISEASE STATES

EPA Science Inventory

Genomic and Proteomic Analysis of Surrogate Tissues for Assessing Toxic Exposures and Disease States
David J. Dix and John C. Rockett
Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, USEPA, ...

Longitudinal Mediation Analysis with Time-varying Mediators and Exposures, with Application to Survival Outcomes

PubMed Central

Zheng, Wenjing; van der Laan, Mark

2017-01-01

In this paper, we study the effect of a time-varying exposure mediated by a time-varying intermediate variable. We consider general longitudinal settings, including survival outcomes. At a given time point, the exposure and mediator of interest are influenced by past covariates, mediators and exposures, and affect future covariates, mediators and exposures. Right censoring, if present, occurs in response to past history. To address the challenges in mediation analysis that are unique to these settings, we propose a formulation in terms of random interventions based on conditional distributions for the mediator. This formulation, in particular, allows for well-defined natural direct and indirect effects in the survival setting, and natural decomposition of the standard total effect. Upon establishing identifiability and the corresponding statistical estimands, we derive the efficient influence curves and establish their robustness properties. Applying Targeted Maximum Likelihood Estimation, we use these efficient influence curves to construct multiply robust and efficient estimators. We also present an inverse probability weighted estimator and a nested non-targeted substitution estimator for these parameters. PMID:29387520

Arsenic exposure and oral cavity lesions in Bangladesh.

PubMed

Syed, Emdadul H; Melkonian, Stephanie; Poudel, Krishna C; Yasuoka, Junko; Otsuka, Keiko; Ahmed, Alauddin; Islam, Tariqul; Parvez, Faruque; Slavkovich, Vesna; Graziano, Joseph H; Ahsan, Habibul; Jimba, Masamine

2013-01-01

To evaluate the relationship between arsenic exposure and oral cavity lesions among an arsenic-exposed population in Bangladesh. We carried out an analysis utilizing the baseline data of the Health Effects of Arsenic Exposure Longitudinal Study, which is an ongoing population-based cohort study to investigate health outcomes associated with arsenic exposure via drinking water in Araihazar, Bangladesh. We used multinomial regression models to estimate the risk of oral cavity lesions. Participants with high urinary arsenic levels (286.1 to 5000.0 μg/g) were more likely to develop arsenical lesions of the gums (multinomial odds ratio = 2.90; 95% confidence interval, 1.11 to 7.54), and tongue (multinomial odds ratio = 2.79; 95% confidence interval, 1.51 to 5.15), compared with those with urinary arsenic levels of 7.0 to 134.0 μg/g. Higher level of arsenic exposure was positively associated with increased arsenical lesions of the gums and tongue.

COVARIATE-ADAPTIVE CLUSTERING OF EXPOSURES FOR AIR POLLUTION EPIDEMIOLOGY COHORTS*

PubMed Central

Keller, Joshua P.; Drton, Mathias; Larson, Timothy; Kaufman, Joel D.; Sandler, Dale P.; Szpiro, Adam A.

2017-01-01

Cohort studies in air pollution epidemiology aim to establish associations between health outcomes and air pollution exposures. Statistical analysis of such associations is complicated by the multivariate nature of the pollutant exposure data as well as the spatial misalignment that arises from the fact that exposure data are collected at regulatory monitoring network locations distinct from cohort locations. We present a novel clustering approach for addressing this challenge. Specifically, we present a method that uses geographic covariate information to cluster multi-pollutant observations and predict cluster membership at cohort locations. Our predictive k-means procedure identifies centers using a mixture model and is followed by multi-class spatial prediction. In simulations, we demonstrate that predictive k-means can reduce misclassification error by over 50% compared to ordinary k-means, with minimal loss in cluster representativeness. The improved prediction accuracy results in large gains of 30% or more in power for detecting effect modification by cluster in a simulated health analysis. In an analysis of the NIEHS Sister Study cohort using predictive k-means, we find that the association between systolic blood pressure (SBP) and long-term fine particulate matter (PM2.5) exposure varies significantly between different clusters of PM2.5 component profiles. Our cluster-based analysis shows that for subjects assigned to a cluster located in the Midwestern U.S., a 10 μg/m3 difference in exposure is associated with 4.37 mmHg (95% CI, 2.38, 6.35) higher SBP. PMID:28572869

Occupational exposure to respirable crystalline silica and chronic non-malignant renal disease: systematic review and meta-analysis.

PubMed

Möhner, Matthias; Pohrt, Anne; Gellissen, Johannes

2017-10-01

While occupational exposure to respirable silica is known to lead to lung disease, most notably silicosis, its association with chronic kidney disease is unclear. This review explores the association between occupational exposure to respirable silica and chronic non-malignant renal disease such as glomerulonephritis. The evidence has been collected and compiled. Possible sources of bias are thoroughly discussed. Cohort studies with silica exposure and case-control studies of renal disease were searched in PubMed until January 2015. Two authors independently abstracted data; any disagreement was resolved by consulting a third reviewer. A meta-analysis was performed to evaluate the association to silica exposure. A total of 23 cohort and four case-control studies were included in the analysis. The meta-analysis of cohort studies yielded elevated overall SMRs for renal disease. Some studies, however, included dose-response analyses, most of which did not show a positive trend. The approaches and results of the case-control studies were very heterogeneous. While the studies of cohorts exposed to silica found elevated SMRs for renal disease, no clear evidence of a dose-response relationship emerged. The elevated risk may be attributed to diagnostic and methodological issues. In order to permit a reliable estimation of a possible causal link, exposed cohorts should be monitored for renal disease, as the information from mortality studies is hardly reliable in this field.

Alcohol exposure during development: analysis of effects on female sexual behavior.

PubMed

Gass, Justin T; Jenkins, William J; Marino, Melissa D; Lugo, Joaquin N; Kelly, Sandra J

2007-12-01

Alcohol exposure during development has been shown to alter a variety of social behaviors in both humans and rodents. Sexual behavior in rodents has been well characterized and lends itself to a detailed investigation of the manner in which ethanol impacts this particular social behavior. Rats were exposed to ethanol during both the prenatal and early postnatal period (ET). Control groups included rats exposed to the administration procedures alone (intubated-control) and nontreated controls (NC). Sexual behavior of intact naïve female rats in estrus was assessed in adulthood (approximately postnatal day 90) and activity was measured by the number of crossings between chambers in the 3-chamber test apparatus. A separate study examined the olfactory preferences for 4 odors by intact naïve female rats in all 3 groups. The 4 odors were the odors resulting from 1 hour of occupation of the test chamber by an intact male, 1 hour of occupation of the test chamber by a gonadectomized male, 0.5 ml of urine from an intact male, and 0.5 ml of urine from a gonadectomized male. ET female rats showed a reduced return latency after ejaculation compared to both control groups. There was a trend toward a reduction in percent exits after all forms of male behavior in the ET animals compared to the control groups. No significant differences across groups were seen in the lordosis quotient, activity, or the behavior of the nonexperimental male. ET female rats showed a reduced preference for the odor from the intact male compared to both control groups and a reduced preference for the odor from the gonadectomized male compared to NC females only. These data suggest that ethanol exposure during the prenatal and postnatal period in females alters sexual motivation and changes the processing of olfactory cues and possibly coital cues from male rats.

Use of direct versus indirect preparation data for assessing risk associated with airborne exposures at asbestos-contaminated sites.

PubMed

Goldade, Mary Patricia; O'Brien, Wendy Pott

2014-01-01

At asbestos-contaminated sites, exposure assessment requires measurement of airborne asbestos concentrations; however, the choice of preparation steps employed in the analysis has been debated vigorously among members of the asbestos exposure and risk assessment communities for many years. This study finds that the choice of preparation technique used in estimating airborne amphibole asbestos exposures for risk assessment is generally not a significant source of uncertainty. Conventionally, the indirect preparation method has been less preferred by some because it is purported to result in false elevations in airborne asbestos concentrations, when compared to direct analysis of air filters. However, airborne asbestos sampling in non-occupational settings is challenging because non-asbestos particles can interfere with the asbestos measurements, sometimes necessitating analysis via indirect preparation. To evaluate whether exposure concentrations derived from direct versus indirect preparation techniques differed significantly, paired measurements of airborne Libby-type amphibole, prepared using both techniques, were compared. For the evaluation, 31 paired direct and indirect preparations originating from the same air filters were analyzed for Libby-type amphibole using transmission electron microscopy. On average, the total Libby-type amphibole airborne exposure concentration was 3.3 times higher for indirect preparation analysis than for its paired direct preparation analysis (standard deviation = 4.1), a difference which is not statistically significant (p = 0.12, two-tailed, Wilcoxon signed rank test). The results suggest that the magnitude of the difference may be larger for shorter particles. Overall, neither preparation technique (direct or indirect) preferentially generates more precise and unbiased data for airborne Libby-type amphibole concentration estimates. The indirect preparation method is reasonable for estimating Libby-type amphibole exposure and

Biological monitoring of smoke exposure among wildland firefighters: A pilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2009-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest ServiceFSavannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribedburn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relating changes inmore » urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small sample

Biological monitoring of smoke exposure among wildland firefighters: A pilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particulate matter, and levoglucosan.

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

Neitzel, R.; Naeher, L., P.; Paulsen, M.

2009-04-01

Urinary methoxyphenols (MPs) have been proposed as biomarkers of woodsmoke exposure. However, few field studies have been undertaken to evaluate the relationship between woodsmoke exposure and urinary MP concentrations. We conducted a pilot study at the US Forest Service Savannah River Site, in which carbon monoxide (CO), levoglucosan (LG), and particulate matter (PM2.5) exposures were measured in wildland firefighters on prescribed burn days. Pre- and post-shift urine samples were collected from each subject, and cross-shift changes in creatinine-corrected urinary MP concentrations were calculated. Correlations between exposure measures and creatine-adjusted urinary MP concentrations were explored, and regression models were developed relatingmore » changes in urinary MP concentrations to measured exposure levels. Full-shift measurements were made on 13 firefighters over 20 work shifts in winter 2004 at the US Forest Service Savannah River site, a National Environmental Research Park. The average workshift length across the 20 measured shifts was 701±95 min. LG and CO exposures were significantly correlated for samples where the filter measurement captured at least 60% of the work shift (16 samples), as well as for the smaller set of full-shift exposure samples (n¼9). PM2.5 and CO exposures were not significantly correlated, and LG and PM2.5 exposures were only significantly correlated for samples representing at least 60% of the work shift. Creatinine-corrected urinary concentrations for 20 of the 22 MPs showed cross-shift increases, with 14 of these changes showing statistical significance. Individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, and random-effects regression models including CO and LG exposure levels explained up to 80% of the variance in cross-shift changes in summed creatinine-adjusted guaiacol urinary MP concentrations. Although limited by the small

Temporal observations of bright soil exposures at Gusev crater, Mars

USGS Publications Warehouse

Rice, M.S.; Bell, J.F.; Cloutis, E.A.; Wray, J.J.; Herkenhoff, K. E.; Sullivan, R.; Johnson, J. R.; Anderson, R.B.

2011-01-01

The Mars Exploration Rover Spirit has discovered bright soil deposits in its wheel tracks that previously have been confirmed to contain ferric sulfates and/or opaline silica. Repeated Pancam multispectral observations have been acquired at four of these deposits to monitor spectral and textural changes over time during exposure to Martian surface conditions. Previous studies suggested that temporal spectral changes occur because of mineralogic changes (e.g., phase transitions accompanying dehydration). In this study, we present a multispectral and temporal analysis of eight Pancam image sequences at the Tyrone exposure, three at the Gertrude Weise exposure, two at the Kit Carson exposure, and ten at the Ulysses exposure that have been acquired as of sol 2132 (1 January 2010). We compare observed variations in Pancam data to spectral changes predicted by laboratory experiments for the dehydration of ferric sulfates. We also present a spectral analysis of repeated Mars Reconnaissance Orbiter HiRISE observations spanning 32 sols and a textural analysis of Spirit Microscopic Imager observations of Ulysses spanning 102 sols. At all bright soil exposures, we observe no statistically significant spectral changes with time that are uniquely diagnostic of dehydration and/or mineralogic phase changes. However, at Kit Carson and Ulysses, we observe significant textural changes, including slumping within the wheel trench, movement of individual grains, disappearance of fines, and dispersal of soil clods. All observed textural changes are consistent with aeolian sorting and/or minor amounts of air fall dust deposition. Copyright 2011 by the American Geophysical Union.

Exposure to Poverty and Productivity.

PubMed

Dalton, Patricio S; Gonzalez Jimenez, Victor H; Noussair, Charles N

2017-01-01

We study whether exposure to poverty can induce affective states that decrease productivity. In a controlled laboratory setting, we find that subjects randomly assigned to a treatment, in which they view a video featuring individuals that live in extreme poverty, exhibit lower subsequent productivity compared to subjects assigned to a control treatment. Questionnaire responses, as well as facial recognition software, provide quantitative measures of the affective state evoked by the two treatments. Subjects exposed to images of poverty experience a more negative affective state than those in the control treatment. Further analysis shows that individuals in a more positive emotional state exhibit less of a treatment effect. Also, those who exhibit greater attentiveness upon viewing the poverty video are less productive. The results are consistent with the notion that exposure to poverty can induce a psychological state in individuals that adversely affects productivity.

Comparative Analysis of State Fish Consumption Advisories Targeting Sensitive Populations

PubMed Central

Scherer, Alison C.; Tsuchiya, Ami; Younglove, Lisa R.; Burbacher, Thomas M.; Faustman, Elaine M.

2008-01-01

Objective Fish consumption advisories are issued to warn the public of possible toxicological threats from consuming certain fish species. Although developing fetuses and children are particularly susceptible to toxicants in fish, fish also contain valuable nutrients. Hence, formulating advice for sensitive populations poses challenges. We conducted a comparative analysis of advisory Web sites issued by states to assess health messages that sensitive populations might access. Data sources We evaluated state advisories accessed via the National Listing of Fish Advisories issued by the U.S. Environmental Protection Agency. Data extraction We created criteria to evaluate advisory attributes such as risk and benefit message clarity. Data synthesis All 48 state advisories issued at the time of this analysis targeted children, 90% (43) targeted pregnant women, and 58% (28) targeted women of childbearing age. Only six advisories addressed single contaminants, while the remainder based advice on 2–12 contaminants. Results revealed that advisories associated a dozen contaminants with specific adverse health effects. Beneficial health effects of any kind were specifically associated only with omega-3 fatty acids found in fish. Conclusions These findings highlight the complexity of assessing and communicating information about multiple contaminant exposure from fish consumption. Communication regarding potential health benefits conferred by specific fish nutrients was minimal and focused primarily on omega-3 fatty acids. This overview suggests some lessons learned and highlights a lack of both clarity and consistency in providing the breadth of information that sensitive populations such as pregnant women need to make public health decisions about fish consumption during pregnancy. PMID:19079708

Individual and collective exposure to political violence: Palestinian adolescents coping with conflict.

PubMed

Giacaman, Rita; Shannon, Harry S; Saab, Hana; Arya, Neil; Boyce, Will

2007-08-01

We conducted a survey of Palestinian adolescents in school. We hypothesized that collective and individual exposures to violence would both negatively affect adolescents' mental health. We also anticipated that the negative effect of collective exposures on mental health would be less than that of individual exposures. Our analysis was designed to test these hypotheses. A representative sample of 3415 students of 10th and 11th grades from the Ramallah District of the West Bank participated in the survey. The primary independent variables were scales of individual and collective exposures to trauma/violence (ETV) by the Israeli military and settlers. Factor analysis revealed several sub-scales. Outcome measures were constructed and included: a binary measure of depressive-like states, and emotional, depressive-like state, and somatic scales. Several variables were identified as possible covariates: gender, age, school-type, residence, employment status of father, and identity documents held. Logistic and multiple regression analyses revealed a strong relationship between ETV and adolescents' mental health, with both individual and collective exposures having independent effects. There was a higher prevalence of depressive-like symptoms among girls compared with boys, and in adolescents living in Palestinian refugee camps compared with those living in cities, towns and villages. The findings confirmed our hypothesis that both individual and collective ETV independently affect the mental health of adolescents. Contrary to expectations, individual exposures did not consistently have a greater negative effect on health outcomes than collective exposures, although the sub-scale of direct personal exposures to violence consistently showed the strongest effect among sub-scales. The results emphasize the importance of going beyond individual experiences and including the health outcomes of collective violation when analyzing violent and traumatic contexts.

Vulnerability of Thai rice production to simultaneous climate and socioeconomic changes: a double exposure analysis

NASA Astrophysics Data System (ADS)

Sangpenchan, R.

2011-12-01

This research explores the vulnerability of Thai rice production to simultaneous exposure by climate and socioeconomic change -- so-called "double exposure." Both processes influence Thailand's rice production system, but the vulnerabilities associated with their interactions are unknown. To understand this double exposure, I adopts a mixed-method, qualitative-quantitative analytical approach consisting of three phases of analysis involving a Vulnerability Scoping Diagram, a Principal Component Analysis, and the EPIC crop model using proxy datasets collected from secondary data sources at provincial scales.The first and second phases identify key variables representing each of the three dimensions of vulnerability -- exposure, sensitivity, and adaptive capacity indicating that the greatest vulnerability in the rice production system occurs in households and areas with high exposure to climate change, high sensitivity to climate and socioeconomic stress, and low adaptive capacity. In the third phase, the EPIC crop model simulates rice yields associated with future climate change projected by CSIRO and MIROC climate models. Climate change-only scenarios project the decrease in yields by 10% from the current productivity during 2016-2025 and 30% during 2045-2054. Scenarios applying both climate change and improved technology and management practices show that a 50% increase in rice production is possible, but requires strong collaboration between sectors to advance agricultural research and technology and requires strong adaptive capacity in the rice production system characterized by well-developed social capital, social networks, financial capacity, and infrastructure and household mobility at the local scale. The vulnerability assessment and climate and crop adaptation simulations used here provide useful information to decision makers developing vulnerability reduction plans in the face of concurrent climate and socioeconomic change.

Association between Occupational Exposure to Wood Dust and Cancer: A Systematic Review and Meta-Analysis

PubMed Central

Alonso-Sardón, Montserrat; Chamorro, Antonio-J.; Hernández-García, Ignacio; Iglesias-de-Sena, Helena; Martín-Rodero, Helena; Herrera, Cristian; Marcos, Miguel; Mirón-Canelo, José Antonio

2015-01-01

Objective To perform a systematic review to analyze the association between occupational exposure to wood dust and cancer. Methods A systematic literature search of entries made in the MEDLINE-PubMed database between 1957 and 2013 was conducted to identify studies that had assessed the relationship between occupational exposure to wood dust and different types of cancer. A meta-analysis of selected case-control and cohort studies was subsequently performed. Results A total of 114 studies were identified and 70 were selected for review. Of these, 42 studies focused on the relationship between wood dust and nasal cancer (n = 22), lung cancer (n = 11), and other types of cancer (n = 9). Low-to-moderate quality evidence that wood dust acts as a carcinogen was obtained, and a stronger association between wood dust and nasal adenocarcinoma was observed. A lesser association between wood dust exposure and lung cancer was also observed. Several studies suggested that there is a relationship between wood dust and the onset of other cancers, although there was no evidence to establish an association. A meta-analysis that included four case-controls studies showed that workers exposed to wood dust exhibited higher rates of nasal adenocarcinoma than other workers (odds ratio = 10.28; 95% confidence interval: 5.92 and 17.85; P<0,0001), although a large degree of heterogeneity was found. Conclusions Low-to-moderate quality evidence supports a causal association between cancer and occupational exposure to wood dust, and this association was stronger for nasal adenocarcinoma than for lung cancer. There was no evidence of an association between wood dust exposure and the other cancers examined. PMID:26191795

Systematic Review with Network Meta-Analysis: Comparative Efficacy of Biologics in the Treatment of Moderately to Severely Active Ulcerative Colitis

PubMed Central

Vickers, Adrian D.; Ainsworth, Claire; Mody, Reema; Bergman, Annika; Ling, Caroline S.; Medjedovic, Jasmina; Smyth, Michael

2016-01-01

Background Biological therapies are increasingly used to treat ulcerative colitis (UC). Aim To compare the efficacy of biologics in adults with moderately-to-severely active UC, stratified by prior exposure to anti-tumour necrosis factor (anti-TNF) therapy. Methods A systematic literature review was undertaken to identify studies of biologics approved for UC. Network meta-analysis was conducted for endpoints at induction and maintenance. Results Seven studies were included in the meta-analysis of induction treatment for anti-TNF therapy-naïve patients. All biologics were more effective than placebo in inducing clinical response, clinical remission, and mucosal healing. Infliximab demonstrated a statistically significant improvement over adalimumab in clinical response (odds ratio [OR] [95% credible interval (CrI)]: 2.19 [1.35–3.55]), clinical remission (OR [95% CrI]: 2.81 [1.49–5.49]), and mucosal healing (OR [95% CrI]: 2.23 [1.21–4.14]); there were no other significant differences between biologics for induction efficacy. Five studies were included in the meta-analysis of maintenance treatment, two studies rerandomised responder patients at end of induction, and three followed the same patients ‘straight through’. To account for design differences, the number of responders at end of induction was assumed to be equivalent to the number rerandomised. Vedolizumab showed significantly different durable clinical response from comparators (OR [95% CrI] infliximab 3.18 [1.14–9.20], golimumab 2.33 [1.04–5.41], and adalimumab 3.96 [1.67–9.84]). In anti-TNF therapy-experienced patients, only vedolizumab and adalimumab could be compared. At induction, no significant differences in efficacy were seen. During maintenance, vedolizumab showed significantly improved rates of mucosal healing versus adalimumab (OR [95% CrI]: 6.72 [1.36–41.0]). Conclusions This study expands the understanding of comparative efficacies of biologic treatments for UC, encompassing

An analysis of employee exposure to organic dust at large-scale composting facilities

NASA Astrophysics Data System (ADS)

Sykes, P.; Allen, J. A.; Wildsmith, J. D.; Jones, K. P.

2009-02-01

The occupational health implications from exposure to dust, endotoxin and 1-3 β Glucan at commercial composting sites are uncertain. This study aims to establish employee exposure levels to inhalable and respirable dust, endotoxin and 1-3 β Glucan during various operational practices in the composting process. Personal samples were collected and the inhalable and respirable dust fractions were determined by gravimetric analysis. Endotoxin concentrations were determined using a Limulus Amebocyte Lysate assay (LAL). 1-3 β Glucan levels were estimated using a specific blocking agent to establish the contribution that these compounds gave to the original endotoxin assay. Employees' exposure to dust was found to be generally lower than the levels stipulated in the Control of Substances Hazardous to Health Regulations (COSHH) 2002 (as amended), (median inhalable fraction 1.08 mg/m3, min 0.25 mg/m3 max 10.80 mg/m3, median respirable fraction 0.05 mg/m3, min 0.02 mg/m3, max 1.49 mg/m3). Determination of the biological component of the dust showed that employees' exposures to endotoxin were elevated (median 31.5 EU/m3, min 2.00 EU/m3, max 1741.78 EU/m3), particularly when waste was agitated (median 175.0 EU/m3, min 2.03 EU/m3, max 1741.78 EU/m3). Eight out of 32 (25%) of the personal exposure data for endotoxin exceeded the 200 EU/m3 temporary legal limit adopted in the Netherlands and thirteen out of 32 (40.6%) exceeded the suggested 50 EU/m3 guidance level suggested to protect workers from respiratory health effects. A significant correlation was observed between employee inhalable dust exposure and personal endotoxin concentration (r = 0.728, p<0.05) and also personal endotoxin exposure and 1-3 β Glucan concentration (r = 0.817, p<0.05). Further work is needed to explore the possibility of using inhalable dust concentration as a predictor for personal endotoxin exposure. The general dust levels stipulated in the COSHH Regulations 2002 (as amended) are inadequate for

Beyond the job exposure matrix (JEM): the task exposure matrix (TEM).

PubMed

Benke, G; Sim, M; Fritschi, L; Aldred, G

2000-09-01

The job exposure matrix (JEM) has been employed to assign cumulative exposure to workers in many epidemiological studies. In these studies, where quantitative data are available, all workers with the same job title and duration are usually assigned similar cumulative exposures, expressed in mgm(-3)xyears. However, if the job is composed of multiple tasks, each with its own specific exposure profile, then assigning all workers within a job the same mean exposure can lead to misclassification of exposure. This variability of exposure within job titles is one of the major weaknesses of JEMs. A method is presented for reducing the variability in the JEM methodology, which has been called the task exposure matrix (TEM). By summing the cumulative exposures of a worker over all the tasks worked within a job title, it is possible to address the variability of exposure within the job title, and reduce possible exposure misclassification. The construction of a TEM is outlined and its application in the context of a study in the primary aluminium industry is described. The TEM was found to assign significantly different cumulative exposures to the majority of workers in the study, compared with the JEM and the degree of difference in cumulative exposure between the JEM and the TEM varied greatly between contaminants.

CRITICA: coding region identification tool invoking comparative analysis

NASA Technical Reports Server (NTRS)

Badger, J. H.; Olsen, G. J.; Woese, C. R. (Principal Investigator)

1999-01-01

Gene recognition is essential to understanding existing and future DNA sequence data. CRITICA (Coding Region Identification Tool Invoking Comparative Analysis) is a suite of programs for identifying likely protein-coding sequences in DNA by combining comparative analysis of DNA sequences with more common noncomparative methods. In the comparative component of the analysis, regions of DNA are aligned with related sequences from the DNA databases; if the translation of the aligned sequences has greater amino acid identity than expected for the observed percentage nucleotide identity, this is interpreted as evidence for coding. CRITICA also incorporates noncomparative information derived from the relative frequencies of hexanucleotides in coding frames versus other contexts (i.e., dicodon bias). The dicodon usage information is derived by iterative analysis of the data, such that CRITICA is not dependent on the existence or accuracy of coding sequence annotations in the databases. This independence makes the method particularly well suited for the analysis of novel genomes. CRITICA was tested by analyzing the available Salmonella typhimurium DNA sequences. Its predictions were compared with the DNA sequence annotations and with the predictions of GenMark. CRITICA proved to be more accurate than GenMark, and moreover, many of its predictions that would seem to be errors instead reflect problems in the sequence databases. The source code of CRITICA is freely available by anonymous FTP (rdp.life.uiuc.edu in/pub/critica) and on the World Wide Web (http:/(/)rdpwww.life.uiuc.edu).

Comparative electrophysiological evaluation of hippocampal function following repeated inhalation exposures to JP-8, Jet A, JP-5, and the synthetic Fischer Tropsch fuel.

PubMed

Rohan, Joyce G; McInturf, Shawn M; Miklasevich, Molly K; Gut, Chester P; Grimm, Michael D; Reboulet, James E; Howard, William R; Mumy, Karen L

2018-01-01

Exposure to fuels continues to be a concern in both military and general populations. The aim of this study was to examine effects of in vivo rat repeated exposures to different types of jet fuel utilizing microelectrode arrays for comparative electrophysiological (EP) measurements in hippocampal slices. Animals were exposed to increasing concentrations of four jet fuels, Jet Propellant (JP)-8, Jet A, JP-5, or synthetic Fischer Tropsch (FT) fuel via whole-body inhalation for 20 d (6 hr/d, 5 d/week for 28 d) and synaptic transmission as well as behavioral performance were assessed. Our behavioral studies indicated no significant changes in behavioral performance in animals exposed to JP-8, Jet A, or JP-5. A significant deviation in learning pattern during the Morris water maze task was observed in rats exposed to the highest concentration of FT (2000 mg/m 3 ). There were also significant differences in the EP profile of hippocampal neurons from animals exposed to JP-8, Jet A, JP-5, or FT compared to control air. However, these differences were not consistent across fuels or dose dependent. As expected, patterns of EP alterations in brain slices from JP-8 and Jet A exposures were more similar compared to those from JP-5 and FT. Further longitudinal investigations are needed to determine if these EP effects are transient or persistent. Such studies may dictate if and how one may use EP measurements to indicate potential susceptibility to neurological impairments, particularly those that result from inhalation exposure to chemicals or mixtures.

Influence of Human Activity Patterns, particle composition, and residential air exchange rates on modeled distributions of PM 2.5 exposure compared with central-site monitoring data

EPA Science Inventory

Central-site monitors do not account for factors such as outdoor-to-indoor transport and human activity patterns that influence personal exposures to ambient fine-particulate matter (PM_2.5). We describe and compare different ambient PM_2.5 exposure estimation...

Epigenome-Wide Meta-Analysis of Methylation in Children Related to Prenatal NO2 Air Pollution Exposure.

PubMed

Gruzieva, Olena; Xu, Cheng-Jian; Breton, Carrie V; Annesi-Maesano, Isabella; Antó, Josep M; Auffray, Charles; Ballereau, Stéphane; Bellander, Tom; Bousquet, Jean; Bustamante, Mariona; Charles, Marie-Aline; de Kluizenaar, Yvonne; den Dekker, Herman T; Duijts, Liesbeth; Felix, Janine F; Gehring, Ulrike; Guxens, Mònica; Jaddoe, Vincent V W; Jankipersadsing, Soesma A; Merid, Simon Kebede; Kere, Juha; Kumar, Ashish; Lemonnier, Nathanael; Lepeule, Johanna; Nystad, Wenche; Page, Christian Magnus; Panasevich, Sviatlana; Postma, Dirkje; Slama, Rémy; Sunyer, Jordi; Söderhäll, Cilla; Yao, Jin; London, Stephanie J; Pershagen, Göran; Koppelman, Gerard H; Melén, Erik

2017-01-01

Prenatal exposure to air pollution is considered to be associated with adverse effects on child health. This may partly be mediated by mechanisms related to DNA methylation. We investigated associations between exposure to air pollution, using nitrogen dioxide (NO2) as marker, and epigenome-wide cord blood DNA methylation. We meta-analyzed the associations between NO2 exposure at residential addresses during pregnancy and cord blood DNA methylation (Illumina 450K) in four European and North American studies (n = 1,508) with subsequent look-up analyses in children ages 4 (n = 733) and 8 (n = 786) years. Additionally, we applied a literature-based candidate approach for antioxidant and anti-inflammatory genes. To assess influence of exposure at the transcriptomics level, we related mRNA expression in blood cells to NO2 exposure in 4- (n = 111) and 16-year-olds (n = 239). We found epigenome-wide significant associations [false discovery rate (FDR) p < 0.05] between maternal NO2 exposure during pregnancy and DNA methylation in newborns for 3 CpG sites in mitochondria-related genes: cg12283362 (LONP1), cg24172570 (3.8 kbp upstream of HIBADH), and cg08973675 (SLC25A28). The associations with cg08973675 methylation were also significant in the older children. Further analysis of antioxidant and anti-inflammatory genes revealed differentially methylated CpGs in CAT and TPO in newborns (FDR p < 0.05). NO2 exposure at the time of biosampling in childhood had a significant impact on CAT and TPO expression. NO2 exposure during pregnancy was associated with differential offspring DNA methylation in mitochondria-related genes. Exposure to NO2 was also linked to differential methylation as well as expression of genes involved in antioxidant defense pathways. Citation: Gruzieva O, Xu CJ, Breton CV, Annesi-Maesano I, Antó JM, Auffray C, Ballereau S, Bellander T, Bousquet J, Bustamante M, Charles MA, de Kluizenaar Y, den Dekker HT, Duijts L, Felix JF, Gehring U, Guxens M, Jaddoe VV

A Longitudinal Analysis of Prenatal Exposure to Methylmercury and Fatty Acids in the Seychelles

PubMed Central

Stokes-Riner, Abbie; Thurston, Sally W.; J.Myers, Gary; Duffy, Emeir M.; Wallace, Julie; Bonham, Maxine; Robson, Paula; Shamlaye, Conrad F.; Strain, J.J.; Watson, Gene

2011-01-01

Background Maternal fish consumption during pregnancy exposes the fetus simultaneously to methyl mercury (MeHg) and long chain polyunsaturated fatty acids (LCPUFA). Data from the Seychelles Child Development Nutrition Study (SCDNS) showed a negative association of MeHg with child development when children were 30 months of age, only when controlling for LCPUFA. Concomitantly, n-3 LCPUFA were found to have a significant positive association only at 9 months. These findings suggest that the effects of MeHg and LCPUFA may vary with age over the first few years of life. We address this by including outcomes at two ages and adjusting for the child's age at testing. Methods A longitudinal analysis utilizing linear mixed models was performed to assess the associations of maternal hair total mercury (THg, a biomarker for MeHg) and maternal LCPUFA with children's Bayley Scales of Infant Development Psychomotor Developmental Index (BSID-II PDI) at 9 and 30 months of age, and to determine whether these associations change over time. Data from 228 children were included. Results Maternal hair MeHg had a negative effect on BSID PDI, while maternal n-3 LCPUFA had a positive effect. These effects did not change significantly from 9 to 30 months in this analysis. Conclusions The longitudinal analysis provides increased power for estimating the relationships of prenatal MeHg and LCPUFA exposures during child development. Significant associations of these exposures in opposite directions confirm the importance of LCPUFA in development and the need to adjust for maternal nutrition when studying prenatal MeHg exposure. PMID:21145963

A longitudinal analysis of prenatal exposure to methylmercury and fatty acids in the Seychelles.

PubMed

Stokes-Riner, Abbie; Thurston, Sally W; Myers, Gary J; Duffy, Emeir M; Wallace, Julie; Bonham, Maxine; Robson, Paula; Shamlaye, Conrad F; Strain, J J; Watson, Gene; Davidson, Philip W

2011-01-01

Maternal fish consumption during pregnancy exposes the fetus simultaneously to methylmercury (MeHg) and long chain polyunsaturated fatty acids (LCPUFA). Data from the Seychelles Child Development Nutrition Study (SCDNS) showed a negative association of MeHg with child development when children were 30 months of age, only when controlling for LCPUFA. Concomitantly, n-3 LCPUFA were found to have a significant positive association only at 9 months. These findings suggest that the effects of MeHg and LCPUFA may vary with age over the first few years of life. We address this by including outcomes at two ages and adjusting for the child's age at testing. A longitudinal analysis utilizing linear mixed models was performed to assess the associations of maternal hair total mercury (THg, a biomarker for MeHg) and maternal LCPUFA with children's Bayley Scales of Infant Development Psychomotor Developmental Index (BSID-II PDI) at 9 and 30 months of age, and to determine whether these associations change over time. Data from 228 children were included. Maternal hair MeHg had a negative effect on BSID PDI, while maternal n-3 LCPUFA had a positive effect. These effects did not change significantly from 9 to 30 months in this analysis. The longitudinal analysis provides increased power for estimating the relationships of prenatal MeHg and LCPUFA exposures during child development. Significant associations of these exposures in opposite directions confirm the importance of LCPUFA in development and the need to adjust for maternal nutrition when studying prenatal MeHg exposure. Copyright © 2010 Elsevier B.V. All rights reserved.

Hepatic Proteome Analysis of Atlantic Salmon (Salmo salar) After Exposure to Environmental Concentrations of Human Pharmaceuticals*

PubMed Central

Hampel, Miriam; Alonso, Esteban; Aparicio, Irene; Santos, Juan Luis; Leaver, Michael

2015-01-01

Pharmaceuticals are pseudopersistent aquatic pollutants with unknown effects at environmentally relevant concentrations. Atlantic salmon (Salmo salar) were exposed to Acetaminophen: 54.77 ± 34.67; Atenolol: 11.08 ± 7.98, and Carbamazepine: 7.85 ± 0.13 μg·L−1 for 5 days. After Acetaminophen treatment, 19 proteins were differently expressed, of which 11 were significant with respect to the control group (eight up-regulated and three down-regulated). After Atenolol treatment, seven differently expressed proteins were obtained in comparison with the control, of which six could be identified (four up-regulated and two down-regulated). Carbamazepine exposure resulted in 15 differently expressed proteins compared with the control, with 10 of them identified (seven up-regulated and three down-regulated). Out of these, three features were common between Acetaminophen and Carbamazepine and one between Carbamazepine and Atenolol. One feature was common across all treatments. Principal component analysis and heat map clustering showed a clear grouping of the variability caused by the applied treatments. The obtained data suggest (1) that exposure to environmentally relevant concentrations of the pharmaceuticals alters the hepatic protein expression profile of the Atlantic salmon; and (2) the existence of treatment specific processes that may be useful for biomarker development. PMID:25394398

Does exposure to the food environment differ by socioeconomic position? Comparing area-based and person-centred metrics in the Fenland Study, UK.

PubMed

Maguire, Eva R; Burgoine, Thomas; Penney, Tarra L; Forouhi, Nita G; Monsivais, Pablo

2017-09-06

Retail food environments (foodscapes) are a recognised determinant of eating behaviours and may contribute to inequalities in diet. However, findings from studies measuring socioeconomic inequality in the foodscape have been mixed, which may be due to methodological differences. The aim of this cross-sectional study was to compare exposure to the foodscape by socioeconomic position using different measures, to test whether the presence, direction or amplitude of differences was sensitive to the choice of foodscape metric or socioeconomic indicator. A sample of 10,429 adults aged 30-64 years with valid home address data were obtained from the Fenland Study, UK. Of this sample, 7270 participants also had valid work location data. The sample was linked to data on food outlets obtained from local government records. Foodscape metrics included count, density and proximity of takeaway outlets and supermarkets, and the percentage of takeaway outlets relative to all food outlets. Exposure metrics were area-based (lower super output areas), and person-centred (proximity to nearest; Euclidean and Network buffers at 800 m, 1 km, and 1 mile). Person-centred buffers were constructed using home and work locations. Socioeconomic status was measured at the area-level (2010 Index of Multiple Deprivation) and the individual-level (highest educational attainment; equivalised household income). Participants were classified into socioeconomic groups and average exposures estimated. Results were analysed using the statistical and percent differences between the highest and lowest socioeconomic groups. In area-based measures, the most deprived areas contained higher takeaway outlet densities (p < 0.001). However, in person-centred metrics lower socioeconomic status was associated with lower exposure to takeaway outlets and supermarkets (all home-based exposures p < 0.001) and socioeconomic differences were greatest at the smallest buffer sizes. Socioeconomic differences in

Characterization of exposure in epidemiological studies on air pollution from biodegradable wastes: Misclassification and comparison of exposure assessment strategies.

PubMed

Cantuaria, Manuella Lech; Suh, Helen; Løfstrøm, Per; Blanes-Vidal, Victoria

2016-11-01

The assignment of exposure is one of the main challenges faced by environmental epidemiologists. However, misclassification of exposures has not been explored in population epidemiological studies on air pollution from biodegradable wastes. The objective of this study was to investigate the use of different approaches for assessing exposure to air pollution from biodegradable wastes by analyzing (1) the misclassification of exposure that is committed by using these surrogates, (2) the existence of differential misclassification (3) the effects that misclassification may have on health effect estimates and the interpretation of epidemiological results, and (4) the ability of the exposure measures to predict health outcomes using 10-fold cross validation. Four different exposure assessment approaches were studied: ammonia concentrations at the residence (Metric I), distance to the closest source (Metric II), number of sources within certain distances from the residence (Metric IIIa,b) and location in a specific region (Metric IV). Exposure-response models based on Metric I provided the highest predictive ability (72.3%) and goodness-of-fit, followed by IV, III and II. When compared to Metric I, Metric IV yielded the best results for exposure misclassification analysis and interpretation of health effect estimates, followed by Metric IIIb, IIIa and II. The study showed that modelled NH 3 concentrations provide more accurate estimations of true exposure than distances-based surrogates, and that distance-based surrogates (especially those based on distance to the closest point source) are imprecise methods to identify exposed populations, although they may be useful for initial studies. Copyright © 2016 Elsevier GmbH. All rights reserved.

EPIDEMIOLOGY AND EXPOSURE ASSESSMENT

EPA Science Inventory

Research collaborations between the National Health and Environmental Effects Research Laboratory (NHEERL) and the National Exposure Research Laboratory (NERL) centered on the development and application of exposure analysis tools in environmental epidemiology include the El Paso...

Direct and Indirect Effects of UV-B Exposure on Litter Decomposition: A Meta-Analysis

PubMed Central

Song, Xinzhang; Peng, Changhui; Jiang, Hong; Zhu, Qiuan; Wang, Weifeng

2013-01-01

Ultraviolet-B (UV-B) exposure in the course of litter decomposition may have a direct effect on decomposition rates via changing states of photodegradation or decomposer constitution in litter while UV-B exposure during growth periods may alter chemical compositions and physical properties of plants. Consequently, these changes will indirectly affect subsequent litter decomposition processes in soil. Although studies are available on both the positive and negative effects (including no observable effects) of UV-B exposure on litter decomposition, a comprehensive analysis leading to an adequate understanding remains unresolved. Using data from 93 studies across six biomes, this introductory meta-analysis found that elevated UV-B directly increased litter decomposition rates by 7% and indirectly by 12% while attenuated UV-B directly decreased litter decomposition rates by 23% and indirectly increased litter decomposition rates by 7%. However, neither positive nor negative effects were statistically significant. Woody plant litter decomposition seemed more sensitive to UV-B than herbaceous plant litter except under conditions of indirect effects of elevated UV-B. Furthermore, levels of UV-B intensity significantly affected litter decomposition response to UV-B (P<0.05). UV-B effects on litter decomposition were to a large degree compounded by climatic factors (e.g., MAP and MAT) (P<0.05) and litter chemistry (e.g., lignin content) (P<0.01). Results suggest these factors likely have a bearing on masking the important role of UV-B on litter decomposition. No significant differences in UV-B effects on litter decomposition were found between study types (field experiment vs. laboratory incubation), litter forms (leaf vs. needle), and decay duration. Indirect effects of elevated UV-B on litter decomposition significantly increased with decay duration (P<0.001). Additionally, relatively small changes in UV-B exposure intensity (30%) had significant direct effects on litter

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

PubMed

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.

Brief Counseling on Secondhand Smoke Exposure in Pregnant Women in Argentina and Uruguay.

PubMed

Alemán, Alicia; Morello, Paola; Colomar, Mercedes; Llambi, Laura; Berrueta, Mabel; Gibbons, Luz; Buekens, Pierre; Althabe, Fernando

2016-12-29

Argentina and Uruguay have a high prevalence of smoking during pregnancy, as well as of secondhand smoke (SHS) exposure. In this secondary analysis of a trial to implement brief smoking cessation counseling during antenatal care in Argentina and Uruguay, we aim to evaluate the effects of the intervention on the rates of self-reported SHS exposure at home and at work, and on attitudes recalled by non-smoker women enrolled in the intervention group compared with the control group. We randomly assigned (1:1) 20 antenatal care clusters in Argentina and Uruguay to receive a multifaceted intervention to implement brief smoking cessation counseling, which also included questions and counseling regarding SHS exposure, or to receive the standard of care. There was not a statistically significant difference between groups of the intervention's effect (reduction of exposure to SHS) on any of the three exposure outcome measures (exposure at home, work or other indoor areas) or on the attitudes of women regarding exposure (avoiding breathing SHS and having rooms where smoking is forbidden). This analysis shows that we should not expect reductions in SHS exposure with this modest intervention alone. To achieve such reductions, strategies engaging partners and other household members may be more effective.

Comparing plasma and X-ray exposure and identifying vulnerable cell parts

NASA Astrophysics Data System (ADS)

Graham, Bill

2012-10-01

Here two issues in plasma medicine that are being addressed in a collaboration between the Centre of Plasma Physics and the School of Pharmacy at Queen's University Belfast and the Plasma Institute at York University UK will be discussed. Recent measurements of the interaction of plasmas created directly in DMEM cell medium and MDAMB-231, a human breast cancer cell line, showed evidence of reduced cell viability and of DNA damage. The same set of experiments were undertaken but with X-ray exposure. A correlation of the dependence on plasma exposure time and X-ray dose was observed which might point the way to dose definition in plasma medicine. We have also been working to identify the cell parts most vulnerable to plasma exposure. In this study a 10 kHz atmospheric pressure non-thermal plasma jet, operating in He/0.5%O2 and characterized to determine the behavior of many of the plasma species, was incident onto the surface of media containing either bacterial strains, in their planktonic and biofilm forms, or isolated bacterial plasmid DNA. The results of measurements to look for changes in plasmid structural conformation, rates of single and double strand breaks, the catalytic activity of certain bacterial enzymes, the peroxidation of lipid content of the bacterial cells, the leakage of ATP and Scanning Electron Microscope (SEM) images will be discussed.

A Bayesian Model and Stochastic Exposure (Dose) Estimation for Relative Exposure Risk Comparison Involving Asbestos-Containing Dropped Ceiling Panel Installation and Maintenance Tasks.

PubMed

Boelter, Fred W; Xia, Yulin; Persky, Jacob D

2017-09-01

Assessing exposures to hazards in order to characterize risk is at the core of occupational hygiene. Our study examined dropped ceiling systems commonly used in schools and commercial buildings and lay-in ceiling panels that may have contained asbestos prior to the mid to late 1970s. However, most ceiling panels and tiles do not contain asbestos. Since asbestos risk relates to dose, we estimated the distribution of eight-hour TWA concentrations and one-year exposures (a one-year dose equivalent) to asbestos fibers (asbestos f/cc-years) for five groups of workers who may encounter dropped ceilings: specialists, generalists, maintenance workers, nonprofessional do-it-yourself (DIY) persons, and other tradespersons who are bystanders to ceiling work. Concentration data (asbestos f/cc) were obtained through two exposure assessment studies in the field and one chamber study. Bayesian and stochastic models were applied to estimate distributions of eight-hour TWAs and annual exposures (dose). The eight-hour TWAs for all work categories were below current and historic occupational exposure limits (OELs). Exposures to asbestos fibers from dropped ceiling work would be categorized as "highly controlled" for maintenance workers and "well controlled" for remaining work categories, according to the American Industrial Hygiene Association exposure control rating system. Annual exposures (dose) were found to be greatest for specialists, followed by maintenance workers, generalists, bystanders, and DIY. On a comparative basis, modeled dose and thus risk from dropped ceilings for all work categories were orders of magnitude lower than published exposures for other sources of banned friable asbestos-containing building material commonly encountered in construction trades. © 2016 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

Extreme weather exposure identification for road networks - a comparative assessment of statistical methods

NASA Astrophysics Data System (ADS)

Schlögl, Matthias; Laaha, Gregor

2017-04-01

The assessment of road infrastructure exposure to extreme weather events is of major importance for scientists and practitioners alike. In this study, we compare the different extreme value approaches and fitting methods with respect to their value for assessing the exposure of transport networks to extreme precipitation and temperature impacts. Based on an Austrian data set from 25 meteorological stations representing diverse meteorological conditions, we assess the added value of partial duration series (PDS) over the standardly used annual maxima series (AMS) in order to give recommendations for performing extreme value statistics of meteorological hazards. Results show the merits of the robust L-moment estimation, which yielded better results than maximum likelihood estimation in 62 % of all cases. At the same time, results question the general assumption of the threshold excess approach (employing PDS) being superior to the block maxima approach (employing AMS) due to information gain. For low return periods (non-extreme events) the PDS approach tends to overestimate return levels as compared to the AMS approach, whereas an opposite behavior was found for high return levels (extreme events). In extreme cases, an inappropriate threshold was shown to lead to considerable biases that may outperform the possible gain of information from including additional extreme events by far. This effect was visible from neither the square-root criterion nor standardly used graphical diagnosis (mean residual life plot) but rather from a direct comparison of AMS and PDS in combined quantile plots. We therefore recommend performing AMS and PDS approaches simultaneously in order to select the best-suited approach. This will make the analyses more robust, not only in cases where threshold selection and dependency introduces biases to the PDS approach but also in cases where the AMS contains non-extreme events that may introduce similar biases. For assessing the performance of

Howard University: A Comparative Fiscal Analysis.

ERIC Educational Resources Information Center

Inman, Deborah; And Others

This report presents a fiscal analysis of Howard University (District of Columbia) including: (1) general education revenues; (2) education and general expenditures; and (3) faculty salaries. The study compared Howard University to four different groups of higher education institutions: similar private institutions with hospitals; public…

A geographical information system-based analysis of cancer mortality and population exposure to coal mining activities in West Virginia, United States of America.

PubMed

Hendryx, Michael; Fedorko, Evan; Anesetti-Rothermel, Andrew

2010-05-01

Cancer incidence and mortality rates are high in West Virginia compared to the rest of the United States of America. Previous research has suggested that exposure to activities of the coal mining industry may contribute to elevated cancer mortality, although exposure measures have been limited. This study tests alternative specifications of exposure to mining activity to determine whether a measure based on location of mines, processing plants, coal slurry impoundments and underground slurry injection sites relative to population levels is superior to a previously-reported measure of exposure based on tons mined at the county level, in the prediction of age-adjusted cancer mortality rates. To this end, we utilize two geographical information system (GIS) techniques--exploratory spatial data analysis and inverse distance mapping--to construct new statistical analyses. Total, respiratory and "other" age-adjusted cancer mortality rates in West Virginia were found to be more highly associated with the GIS-exposure measure than the tonnage measure, before and after statistical control for smoking rates. The superior performance of the GIS measure, based on where people in the state live relative to mining activity, suggests that activities of the industry contribute to cancer mortality. Further confirmation of observed phenomena is necessary with person-level studies, but the results add to the body of evidence that coal mining poses environmental risks to population health in West Virginia.

Sunlight exposure and cardiovascular risk factors in the REGARDS study: a cross-sectional split-sample analysis

PubMed Central

2014-01-01

Background Previous research has suggested that vitamin D and sunlight are related to cardiovascular outcomes, but associations between sunlight and risk factors have not been investigated. We examined whether increased sunlight exposure was related to improved cardiovascular risk factor status. Methods Residential histories merged with satellite, ground monitor, and model reanalysis data were used to determine previous-year sunlight radiation exposure for 17,773 black and white participants aged 45+ from the US. Exploratory and confirmatory analyses were performed by randomly dividing the sample into halves. Logistic regression models were used to examine relationships with cardiovascular risk factors. Results The lowest, compared to the highest quartile of insolation exposure was associated with lower high-density lipoprotein levels in adjusted exploratory (−2.7 mg/dL [95% confidence interval: −4.2, −1.2]) and confirmatory (−1.5 mg/dL [95% confidence interval: −3.0, −0.1]) models. The lowest, compared to the highest quartile of insolation exposure was associated with higher systolic blood pressure levels in unadjusted exploratory and confirmatory, as well as the adjusted exploratory model (2.3 mmHg [95% confidence interval: 0.8, 3.8]), but not the adjusted confirmatory model (1.6 mg/dL [95% confidence interval: −0.5, 3.7]). Conclusions The results of this study suggest that lower long-term sunlight exposure has an association with lower high-density lipoprotein levels. However, all associations were weak, thus it is not known if insolation may affect cardiovascular outcomes through these risk factors. PMID:24946776

Cost Description and Comparative Cost Efficiency of Post-Exposure Prophylaxis and Canine Mass Vaccination against Rabies in N'Djamena, Chad.

PubMed

Mindekem, Rolande; Lechenne, Monique Sarah; Naissengar, Kemdongarti Service; Oussiguéré, Assandi; Kebkiba, Bidjeh; Moto, Daugla Doumagoum; Alfaroukh, Idriss Oumar; Ouedraogo, Laurent Tinoanga; Salifou, Sahidou; Zinsstag, Jakob

2017-01-01

Rabies claims approximately 59,000 human lives annually and is a potential risk to 3.3 billion people in over 100 countries worldwide. Despite being fatal in almost 100% of cases, human rabies can be prevented by vaccinating dogs, the most common vector, and the timely administration of post-exposure prophylaxis (PEP) to exposed victims. For the control and prevention of human rabies in N'Djamena, the capital city of Chad, a free mass vaccination campaign for dogs was organized in 2012 and 2013. The campaigns were monitored by parallel studies on the incidence of canine rabies based on diagnostic testing of suspect animals and the incidence of human bite exposure recorded at selected health facilities. Based on the cost description of the campaign and the need for PEP registered in health centers, three cost scenarios were compared: cumulative cost-efficiency of (1) PEP alone, (2) dog mass vaccination and PEP, (3) dog mass vaccination, PEP, and maximal communication between human health and veterinary workers (One Health communication). Assuming ideal One Health communication, the cumulative prospective cost of dog vaccination and PEP break even with the cumulative prospective cost of PEP alone in the 10th year from the start of the calculation (2012). The cost efficiency expressed in cost per human exposure averted is much higher with canine vaccination and One Health communication than with PEP alone. As shown in other studies, our cost-effectiveness analysis highlights that canine vaccination is financially the best option for animal rabies control and rabies prevention in humans. This study also provides evidence of the beneficial effect of One Health communication. Only with close communication between the human and animal health sectors will the decrease in animal rabies incidence be translated into a decline for PEP. An efficiently applied One Health concept would largely reduce the cost of PEP in resource poor countries and should be implemented for

Cost Description and Comparative Cost Efficiency of Post-Exposure Prophylaxis and Canine Mass Vaccination against Rabies in N’Djamena, Chad

PubMed Central

Mindekem, Rolande; Lechenne, Monique Sarah; Naissengar, Kemdongarti Service; Oussiguéré, Assandi; Kebkiba, Bidjeh; Moto, Daugla Doumagoum; Alfaroukh, Idriss Oumar; Ouedraogo, Laurent Tinoanga; Salifou, Sahidou; Zinsstag, Jakob

2017-01-01

Rabies claims approximately 59,000 human lives annually and is a potential risk to 3.3 billion people in over 100 countries worldwide. Despite being fatal in almost 100% of cases, human rabies can be prevented by vaccinating dogs, the most common vector, and the timely administration of post-exposure prophylaxis (PEP) to exposed victims. For the control and prevention of human rabies in N’Djamena, the capital city of Chad, a free mass vaccination campaign for dogs was organized in 2012 and 2013. The campaigns were monitored by parallel studies on the incidence of canine rabies based on diagnostic testing of suspect animals and the incidence of human bite exposure recorded at selected health facilities. Based on the cost description of the campaign and the need for PEP registered in health centers, three cost scenarios were compared: cumulative cost-efficiency of (1) PEP alone, (2) dog mass vaccination and PEP, (3) dog mass vaccination, PEP, and maximal communication between human health and veterinary workers (One Health communication). Assuming ideal One Health communication, the cumulative prospective cost of dog vaccination and PEP break even with the cumulative prospective cost of PEP alone in the 10th year from the start of the calculation (2012). The cost efficiency expressed in cost per human exposure averted is much higher with canine vaccination and One Health communication than with PEP alone. As shown in other studies, our cost-effectiveness analysis highlights that canine vaccination is financially the best option for animal rabies control and rabies prevention in humans. This study also provides evidence of the beneficial effect of One Health communication. Only with close communication between the human and animal health sectors will the decrease in animal rabies incidence be translated into a decline for PEP. An efficiently applied One Health concept would largely reduce the cost of PEP in resource poor countries and should be implemented for

Audiometric Notch and Extended High-Frequency Hearing Threshold Shift in Relation to Total Leisure Noise Exposure: An Exploratory Analysis

PubMed Central

Wei, Wenjia; Heinze, Stefanie; Gerstner, Doris G.; Walser, Sandra M.; Twardella, Dorothee; Reiter, Christina; Weilnhammer, Veronika; Perez-Alvarez, Carmelo; Steffens, Thomas; Herr, Caroline E.W.

2017-01-01

Background: Studies investigating leisure noise effect on extended high frequency hearing are insufficient and they have inconsistent results. The aim of this study was to investigate if extended high-frequency hearing threshold shift is related to audiometric notch, and if total leisure noise exposure is associated with extended high-frequency hearing threshold shift. Materials and Methods: A questionnaire of the Ohrkan cohort study was used to collect information on demographics and leisure time activities. Conventional and extended high-frequency audiometry was performed. We did logistic regression between extended high-frequency hearing threshold shift and audiometric notch as well as between total leisure noise exposure and extended high-frequency hearing threshold shift. Potential confounders (sex, school type, and firecrackers) were included. Results: Data from 278 participants (aged 18–23 years, 53.2% female) were analyzed. Associations between hearing threshold shift at 10, 11.2, 12.5, and 14 kHz with audiometric notch were observed with a higher prevalence of threshold shift at the four frequencies, compared to the notch. However, we found no associations between total leisure noise exposure and hearing threshold shift at any extended high frequency. Conclusion: This exploratory analysis suggests that while extended high-frequency hearing threshold shifts are not related to total leisure noise exposure, they are strongly associated with audiometric notch. This leads us to further explore the hypothesis that extended high-frequency threshold shift might be indicative of the appearance of audiometric notch at a later time point, which can be investigated in the future follow-ups of the Ohrkan cohort. PMID:29319010

Audiometric notch and extended high-frequency hearing threshold shift in relation to total leisure noise exposure: An exploratory analysis.

PubMed

Wei, Wenjia; Heinze, Stefanie; Gerstner, Doris G; Walser, Sandra M; Twardella, Dorothee; Reiter, Christina; Weilnhammer, Veronika; Perez-Alvarez, Carmelo; Steffens, Thomas; Herr, Caroline E W

2017-01-01

Studies investigating leisure noise effect on extended high frequency hearing are insufficient and they have inconsistent results. The aim of this study was to investigate if extended high-frequency hearing threshold shift is related to audiometric notch, and if total leisure noise exposure is associated with extended high-frequency hearing threshold shift. A questionnaire of the Ohrkan cohort study was used to collect information on demographics and leisure time activities. Conventional and extended high-frequency audiometry was performed. We did logistic regression between extended high-frequency hearing threshold shift and audiometric notch as well as between total leisure noise exposure and extended high-frequency hearing threshold shift. Potential confounders (sex, school type, and firecrackers) were included. Data from 278 participants (aged 18-23 years, 53.2% female) were analyzed. Associations between hearing threshold shift at 10, 11.2, 12.5, and 14 kHz with audiometric notch were observed with a higher prevalence of threshold shift at the four frequencies, compared to the notch. However, we found no associations between total leisure noise exposure and hearing threshold shift at any extended high frequency. This exploratory analysis suggests that while extended high-frequency hearing threshold shifts are not related to total leisure noise exposure, they are strongly associated with audiometric notch. This leads us to further explore the hypothesis that extended high-frequency threshold shift might be indicative of the appearance of audiometric notch at a later time point, which can be investigated in the future follow-ups of the Ohrkan cohort.

Occupational exposure to polychlorinated biphenyls and risk of cutaneous melanoma: a meta-analysis.

PubMed

Boffetta, Paolo; Catalani, Simona; Tomasi, Cesare; Pira, Enrico; Apostoli, Pietro

2018-01-01

The aim of this study was to carry out a meta-analysis of studies on exposure to polychlorinated biphenyls (PCBs) and the risk of malignant melanoma (MM). We searched Scopus, PubMed, and reference lists; among 807 potentially relevant articles, we selected those based on 12 populations. Data were extracted according to a standardized form; the Newcastle-Ottawa Scale was used to assess study quality. Meta-analyses were carried out according to fixed-effect and random-effects models. The fixed-effect summary relative risk (RR) for MM was 0.91 [95% confidence interval (CI): 0.82-1.00]; the random-effects summary RR was 1.05 (95% CI: 0.78-1.32). The random-effects summary RR from eight occupational cohorts was 1.13 (95% CI: 0.91-1.35) and that from four community-based studies was 0.84 (95% CI: 0.36-1.31). The quality of the studies and the methods for PCB exposure assessment did not influence the RR. These results do not support the hypothesis of an association between PCB exposure and the risk of MM.

National Launch System comparative economic analysis

NASA Technical Reports Server (NTRS)

Prince, A.

1992-01-01

Results are presented from an analysis of economic benefits (or losses), in the form of the life cycle cost savings, resulting from the development of the National Launch System (NLS) family of launch vehicles. The analysis was carried out by comparing various NLS-based architectures with the current Shuttle/Titan IV fleet. The basic methodology behind this NLS analysis was to develop a set of annual payload requirements for the Space Station Freedom and LEO, to design launch vehicle architectures around these requirements, and to perform life-cycle cost analyses on all of the architectures. A SEI requirement was included. Launch failure costs were estimated and combined with the relative reliability assumptions to measure the effects of losses. Based on the analysis, a Shuttle/NLS architecture evolving into a pressurized-logistics-carrier/NLS architecture appears to offer the best long-term cost benefit.

Meta-analysis of benzene exposure and non-Hodgkin lymphoma: biases could mask an important association

PubMed Central

Steinmaus, C; Smith, A H; Jones, R M; Smith, M T

2015-01-01

Objectives Benzene is a widely recognised cause of leukaemia but its association with non-Hodgkin’s lymphoma (NHL) is less well established. The goal of this project is to review the current published literature on this association. Methods We performed a meta-analysis of cohort and case-control studies of benzene exposure and NHL and a meta-analysis of NHL and refinery work, a potential source of benzene exposure. Results In 22 studies of benzene exposure, the summary relative risk for NHL was 1.22 (95% CI 1.02 to 1.47; one-sided p value = 0.01). When studies that likely included unexposed subjects in the “exposed” group were excluded, the summary relative risk increased to 1.49 (95% CI 1.12 to 1.97, n = 13), and when studies based solely on self-reported work history were excluded, the relative risk rose to 2.12 (95% CI 1.11 to 4.02, n = 6). In refinery workers, the summary relative risk for NHL in all 21 studies was 1.21 (95% CI 1.00 to 1.46; p = 0.02). When adjusted for the healthy worker effect, this relative risk estimate increased to 1.42 (95% CI 1.19 to 1.69). Conclusions The finding of elevated relative risks in studies of both benzene exposure and refinery work provides further evidence that benzene exposure causes NHL. In addition, the finding of increased relative risks after removing studies that included unexposed or lesser exposed workers in “exposed” cohorts, and increased relative risk estimates after adjusting for the healthy worker effect, suggest that effects of benzene on NHL might be missed in occupational studies if these biases are not accounted for. PMID:18417556

A case-control study of diesel exhaust exposure and bladder cancer.

PubMed

Wynder, E L; Dieck, G S; Hall, N E; Lahti, H

1985-08-01

The relationship between bladder cancer and employment in occupations involving exposure to diesel exhaust was examined using data from a hospital-based case-control study of men aged 20 to 80 years in 18 hospitals in six U.S. cities, from January 1981 to May 1983. In this analysis, 194 cases and 582 controls were compared according to occupation, smoking history, alcohol and coffee consumption, and various demographic variables. No difference was found in the proportion of bladder cancer cases employed in occupations with exposure to diesel exhaust compared to controls. This relationship did not change after taking smoking habits into account. Bladder cancer cases were significantly more likely to be current smokers of cigarettes than were controls.

A Comparative Toxidrome Analysis of Human Organophosphate and Nerve Agent Poisonings Using Social Media

PubMed Central

Colman, E

2017-01-01

Here we utilized social media to compare the toxidrome of three lethal chemical exposures worldwide. YouTube videos were the main source from which the data were collected, but published reports and news were also utilized to fill in some gaps. All videos were organized in a database detailing symptoms and severity of each victim, along with demographics such as approximate age and gender. Each symptom was rated as mild, moderate, or severe and corresponding pie graphs for each incident were compared. The videos displayed symptoms ranging from mild to severe cholinergic toxicity and life‐threatening convulsions. Social media may represent an important resource in developing a viable approach to the early detection and identification of chemical exposure, reinforce our preparedness for better antidotes, long‐term follow up, and training about deadly chemical nerve agent attacks. PMID:28238224

Comparative Genome Analysis of Enterobacter cloacae

PubMed Central

Liu, Wing-Yee; Wong, Chi-Fat; Chung, Karl Ming-Kar; Jiang, Jing-Wei; Leung, Frederick Chi-Ching

2013-01-01

The Enterobacter cloacae species includes an extremely diverse group of bacteria that are associated with plants, soil and humans. Publication of the complete genome sequence of the plant growth-promoting endophytic E. cloacae subsp. cloacae ENHKU01 provided an opportunity to perform the first comparative genome analysis between strains of this dynamic species. Examination of the pan-genome of E. cloacae showed that the conserved core genome retains the general physiological and survival genes of the species, while genomic factors in plasmids and variable regions determine the virulence of the human pathogenic E. cloacae strain; additionally, the diversity of fimbriae contributes to variation in colonization and host determination of different E. cloacae strains. Comparative genome analysis further illustrated that E. cloacae strains possess multiple mechanisms for antagonistic action against other microorganisms, which involve the production of siderophores and various antimicrobial compounds, such as bacteriocins, chitinases and antibiotic resistance proteins. The presence of Type VI secretion systems is expected to provide further fitness advantages for E. cloacae in microbial competition, thus allowing it to survive in different environments. Competition assays were performed to support our observations in genomic analysis, where E. cloacae subsp. cloacae ENHKU01 demonstrated antagonistic activities against a wide range of plant pathogenic fungal and bacterial species. PMID:24069314

Exposure to Poverty and Productivity

PubMed Central

2017-01-01

We study whether exposure to poverty can induce affective states that decrease productivity. In a controlled laboratory setting, we find that subjects randomly assigned to a treatment, in which they view a video featuring individuals that live in extreme poverty, exhibit lower subsequent productivity compared to subjects assigned to a control treatment. Questionnaire responses, as well as facial recognition software, provide quantitative measures of the affective state evoked by the two treatments. Subjects exposed to images of poverty experience a more negative affective state than those in the control treatment. Further analysis shows that individuals in a more positive emotional state exhibit less of a treatment effect. Also, those who exhibit greater attentiveness upon viewing the poverty video are less productive. The results are consistent with the notion that exposure to poverty can induce a psychological state in individuals that adversely affects productivity. PMID:28125621

Mercury analysis in hair: Comparability and quality assessment within the transnational COPHES/DEMOCOPHES project.

PubMed

Esteban, Marta; Schindler, Birgit Karin; Jiménez, José Antonio; Koch, Holger Martin; Angerer, Jürgen; Rosado, Montserrat; Gómez, Silvia; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Becker, Kerstin; Bloemen, Louis; Schoeters, Greet; Den Hond, Elly; Sepai, Ovnair; Exley, Karen; Horvat, Milena; Knudsen, Lisbeth E; Joas, Anke; Joas, Reinhard; Aerts, Dominique; Biot, Pierre; Borošová, Daniela; Davidson, Fred; Dumitrascu, Irina; Fischer, Marc E; Grander, Margaretha; Janasik, Beata; Jones, Kate; Kašparová, Lucie; Larssen, Thorjørn; Naray, Miklos; Nielsen, Flemming; Hohenblum, Philipp; Pinto, Rui; Pirard, Catherine; Plateel, Gregory; Tratnik, Janja Snoj; Wittsiepe, Jürgen; Castaño, Argelia

2015-08-01

Human biomonitoring (HBM) is an effective tool for assessing actual exposure to chemicals that takes into account all routes of intake. Although hair analysis is considered to be an optimal biomarker for assessing mercury exposure, the lack of harmonization as regards sampling and analytical procedures has often limited the comparison of data at national and international level. The European-funded projects COPHES and DEMOCOPHES developed and tested a harmonized European approach to Human Biomonitoring in response to the European Environment and Health Action Plan. Herein we describe the quality assurance program (QAP) for assessing mercury levels in hair samples from more than 1800 mother-child pairs recruited in 17 European countries. To ensure the comparability of the results, standard operating procedures (SOPs) for sampling and for mercury analysis were drafted and distributed to participating laboratories. Training sessions were organized for field workers and four external quality-assessment exercises (ICI/EQUAS), followed by the corresponding web conferences, were organized between March 2011 and February 2012. ICI/EQUAS used native hair samples at two mercury concentration ranges (0.20-0.71 and 0.80-1.63) per exercise. The results revealed relative standard deviations of 7.87-13.55% and 4.04-11.31% for the low and high mercury concentration ranges, respectively. A total of 16 out of 18 participating laboratories the QAP requirements and were allowed to analyze samples from the DEMOCOPHES pilot study. Web conferences after each ICI/EQUAS revealed this to be a new and effective tool for improving analytical performance and increasing capacity building. The procedure developed and tested in COPHES/DEMOCOPHES would be optimal for application on a global scale as regards implementation of the Minamata Convention on Mercury. Copyright © 2014 Elsevier Inc. All rights reserved.

Long duration exposure facility post-flight thermal analysis: Orbital/thermal environment data package

NASA Technical Reports Server (NTRS)

Berrios, William M.

1990-01-01

A post flight mission thermal environment for the Long Duration Exposure Facility was created as part of the thermal analysis data reduction effort. The data included herein is the thermal parameter data used in the calculation of boundary temperatures. This boundary temperature data is to be released in the near future for use by the LDEF principal investigators in the final analysis of their particular experiment temperatures. Also included is the flight temperature data as recorded by the LDEF Thermal Measurements System (THERM) for the first 90 days of flight.

Exposure-response analysis of alectinib in crizotinib-resistant ALK-positive non-small cell lung cancer.

PubMed

Morcos, Peter N; Nueesch, Eveline; Jaminion, Felix; Guerini, Elena; Hsu, Joy C; Bordogna, Walter; Balas, Bogdana; Mercier, Francois

2018-05-10

Alectinib is a selective and potent anaplastic lymphoma kinase (ALK) inhibitor that is active in the central nervous system (CNS). Alectinib demonstrated robust efficacy in a pooled analysis of two single-arm, open-label phase II studies (NP28673, NCT01801111; NP28761, NCT01871805) in crizotinib-resistant ALK-positive non-small-cell lung cancer (NSCLC): median overall survival (OS) 29.1 months (95% confidence interval [CI]: 21.3-39.0) for alectinib 600 mg twice daily (BID). We investigated exposure-response relationships from final pooled phase II OS and safety data to assess alectinib dose selection. A semi-parametric Cox proportional hazards model analyzed relationships between individual median observed steady-state trough concentrations (C trough,ss ) for combined exposure of alectinib and its major metabolite (M4), baseline covariates (demographics and disease characteristics) and OS. Univariate logistic regression analysis analyzed relationships between C trough,ss and incidence of adverse events (AEs: serious and Grade ≥ 3). Overall, 92% of patients (n = 207/225) had C trough,ss data and were included in the analysis. No statistically significant relationship was found between C trough,ss and OS following alectinib treatment. The only baseline covariates that statistically influenced OS were baseline tumor size and prior crizotinib treatment duration. Larger baseline tumor size and shorter prior crizotinib treatment were both associated with shorter OS. Logistic regression confirmed no significant relationship between C trough,ss and AEs. Alectinib 600 mg BID provides systemic exposures at plateau of response for OS while maintaining a well-tolerated safety profile. This analysis confirms alectinib 600 mg BID as the recommended global dose for patients with crizotinib-resistant ALK-positive NSCLC.

Antibiotic exposure in neonates and early adverse outcomes: a systematic review and meta-analysis.

PubMed

Esaiassen, Eirin; Fjalstad, Jon Widding; Juvet, Lene Kristine; van den Anker, John N; Klingenberg, Claus

2017-07-01

To systematically review and meta-analyse the relationship between antibiotic exposure in neonates and the following early adverse outcomes: necrotizing enterocolitis (NEC), invasive fungal infections (IFIs) and/or death. Data sources were PubMed, Embase, Medline and the Cochrane Database (to December 2016), supplemented by manual searches of reference lists. Randomized controlled trials (RCTs) and observational studies were included if they provided data on different categories of antibiotic exposures (yes versus no, long versus short duration, and/or broad- versus narrow-spectrum regimens) and the risk of developing NEC, IFI and/or death in the neonatal period. Two reviewers extracted data and evaluated the risk of bias using the Cochrane Handbook, adapted to include observational studies. When appropriate, meta-analyses were conducted using the random-effect model. We identified 9 RCTs and 38 observational studies. The quality of the majority of studies was poor to moderate. There was a significant association between prolonged antibiotic exposure and an increased risk of NEC in five observational studies (5003 participants) and/or risk of death in five observational studies (13 534 participants). Eleven of 15 studies with data on broad- versus narrow-spectrum regimens reported an increased risk of IFI after broad-spectrum antibiotic exposure, in particular with third-generation cephalosporins and carbapenems. Meta-analysis was limited by few and old RCTs, insufficient sample sizes and diversity of antibiotic exposure and outcomes reported. Prolonged antibiotic exposure in uninfected preterm infants is associated with an increased risk of NEC and/or death, and broad-spectrum antibiotic exposure is associated with an increased risk of IFI. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Personal Exposure to Mixtures of Volatile Organic Compounds: Modeling and Further Analysis of the RIOPA Data

PubMed Central

Batterman, Stuart; Su, Feng-Chiao; Li, Shi; Mukherjee, Bhramar; Jia, Chunrong

2015-01-01

known to affect VOC exposures, many personal, environmental, and socioeconomic determinants remain to be identified, and the significance and applicability of the determinants reported in the literature are uncertain. To help answer these unresolved questions and overcome limitations of previous analyses, this project used several novel and powerful statistical modeling and analysis techniques and two large data sets. The overall objectives of this project were (1) to identify and characterize exposure distributions (including extreme values), (2) evaluate mixtures (including dependencies), and (3) identify determinants of VOC exposure. METHODS VOC data were drawn from two large data sets: the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study (1999–2001) and the National Health and Nutrition Examination Survey (NHANES; 1999–2000). The RIOPA study used a convenience sample to collect outdoor, indoor, and personal exposure measurements in three cities (Elizabeth, NJ; Houston, TX; Los Angeles, CA). In each city, approximately 100 households with adults and children who did not smoke were sampled twice for 18 VOCs. In addition, information about 500 variables associated with exposure was collected. The NHANES used a nationally representative sample and included personal VOC measurements for 851 participants. NHANES sampled 10 VOCs in common with RIOPA. Both studies used similar sampling methods and study periods. Specific Aim 1 To estimate and model extreme value exposures, extreme value distribution models were fitted to the top 10% and 5% of VOC exposures. Health risks were estimated for individual VOCs and for three VOC mixtures. Simulated extreme value data sets, generated for each VOC and for fitted extreme value and lognormal distributions, were compared with measured concentrations (RIOPA observations) to evaluate each model’s goodness of fit. Mixture distributions were fitted with the conventional finite mixture of normal distributions and the

Exposure measurement error in PM2.5 health effects studies: A pooled analysis of eight personal exposure validation studies

PubMed Central

2014-01-01

Background Exposure measurement error is a concern in long-term PM2.5 health studies using ambient concentrations as exposures. We assessed error magnitude by estimating calibration coefficients as the association between personal PM2.5 exposures from validation studies and typically available surrogate exposures. Methods Daily personal and ambient PM2.5, and when available sulfate, measurements were compiled from nine cities, over 2 to 12 days. True exposure was defined as personal exposure to PM2.5 of ambient origin. Since PM2.5 of ambient origin could only be determined for five cities, personal exposure to total PM2.5 was also considered. Surrogate exposures were estimated as ambient PM2.5 at the nearest monitor or predicted outside subjects’ homes. We estimated calibration coefficients by regressing true on surrogate exposures in random effects models. Results When monthly-averaged personal PM2.5 of ambient origin was used as the true exposure, calibration coefficients equaled 0.31 (95% CI:0.14, 0.47) for nearest monitor and 0.54 (95% CI:0.42, 0.65) for outdoor home predictions. Between-city heterogeneity was not found for outdoor home PM2.5 for either true exposure. Heterogeneity was significant for nearest monitor PM2.5, for both true exposures, but not after adjusting for city-average motor vehicle number for total personal PM2.5. Conclusions Calibration coefficients were <1, consistent with previously reported chronic health risks using nearest monitor exposures being under-estimated when ambient concentrations are the exposure of interest. Calibration coefficients were closer to 1 for outdoor home predictions, likely reflecting less spatial error. Further research is needed to determine how our findings can be incorporated in future health studies. PMID:24410940

Quality Matters: Systematic Analysis of Endpoints Related to “Cellular Life” in Vitro Data of Radiofrequency Electromagnetic Field Exposure

PubMed Central

Simkó, Myrtill; Remondini, Daniel; Zeni, Olga; Scarfi, Maria Rosaria

2016-01-01

Possible hazardous effects of radiofrequency electromagnetic fields (RF-EMF) at low exposure levels are controversially discussed due to inconsistent study findings. Therefore, the main focus of the present study is to detect if any statistical association exists between RF-EMF and cellular responses, considering cell proliferation and apoptosis endpoints separately and with both combined as a group of “cellular life” to increase the statistical power of the analysis. We searched for publications regarding RF-EMF in vitro studies in the PubMed database for the period 1995–2014 and extracted the data to the relevant parameters, such as cell culture type, frequency, exposure duration, SAR, and five exposure-related quality criteria. These parameters were used for an association study with the experimental outcome in terms of the defined endpoints. We identified 104 published articles, from which 483 different experiments were extracted and analyzed. Cellular responses after exposure to RF-EMF were significantly associated to cell lines rather than to primary cells. No other experimental parameter was significantly associated with cellular responses. A highly significant negative association with exposure condition-quality and cellular responses was detected, showing that the more the quality criteria requirements were satisfied, the smaller the number of detected cellular responses. According to our knowledge, this is the first systematic analysis of specific RF-EMF bio-effects in association to exposure quality, highlighting the need for more stringent quality procedures for the exposure conditions. PMID:27420084

Network Analysis in Comparative Social Sciences

ERIC Educational Resources Information Center

Vera, Eugenia Roldan; Schupp, Thomas

2006-01-01

This essay describes the pertinence of Social Network Analysis (SNA) for the social sciences in general, and discusses its methodological and conceptual implications for comparative research in particular. The authors first present a basic summary of the theoretical and methodological assumptions of SNA, followed by a succinct overview of its…

Comparative analysis and visualization of multiple collinear genomes

PubMed Central

2012-01-01

Background Genome browsers are a common tool used by biologists to visualize genomic features including genes, polymorphisms, and many others. However, existing genome browsers and visualization tools are not well-suited to perform meaningful comparative analysis among a large number of genomes. With the increasing quantity and availability of genomic data, there is an increased burden to provide useful visualization and analysis tools for comparison of multiple collinear genomes such as the large panels of model organisms which are the basis for much of the current genetic research. Results We have developed a novel web-based tool for visualizing and analyzing multiple collinear genomes. Our tool illustrates genome-sequence similarity through a mosaic of intervals representing local phylogeny, subspecific origin, and haplotype identity. Comparative analysis is facilitated through reordering and clustering of tracks, which can vary throughout the genome. In addition, we provide local phylogenetic trees as an alternate visualization to assess local variations. Conclusions Unlike previous genome browsers and viewers, ours allows for simultaneous and comparative analysis. Our browser provides intuitive selection and interactive navigation about features of interest. Dynamic visualizations adjust to scale and data content making analysis at variable resolutions and of multiple data sets more informative. We demonstrate our genome browser for an extensive set of genomic data sets composed of almost 200 distinct mouse laboratory strains. PMID:22536897

Epigenome-Wide Meta-Analysis of Methylation in Children Related to Prenatal NO2 Air Pollution Exposure

PubMed Central

Gruzieva, Olena; Xu, Cheng-Jian; Breton, Carrie V.; Annesi-Maesano, Isabella; Antó, Josep M.; Auffray, Charles; Ballereau, Stéphane; Bellander, Tom; Bousquet, Jean; Bustamante, Mariona; Charles, Marie-Aline; de Kluizenaar, Yvonne; den Dekker, Herman T.; Duijts, Liesbeth; Felix, Janine F.; Gehring, Ulrike; Guxens, Mònica; Jaddoe, Vincent V.W.; Jankipersadsing, Soesma A.; Merid, Simon Kebede; Kere, Juha; Kumar, Ashish; Lemonnier, Nathanael; Lepeule, Johanna; Nystad, Wenche; Page, Christian Magnus; Panasevich, Sviatlana; Postma, Dirkje; Slama, Rémy; Sunyer, Jordi; Söderhäll, Cilla; Yao, Jin; London, Stephanie J.; Pershagen, Göran; Koppelman, Gerard H.; Melén, Erik

2016-01-01

Background: Prenatal exposure to air pollution is considered to be associated with adverse effects on child health. This may partly be mediated by mechanisms related to DNA methylation. Objectives: We investigated associations between exposure to air pollution, using nitrogen dioxide (NO2) as marker, and epigenome-wide cord blood DNA methylation. Methods: We meta-analyzed the associations between NO2 exposure at residential addresses during pregnancy and cord blood DNA methylation (Illumina 450K) in four European and North American studies (n = 1,508) with subsequent look-up analyses in children ages 4 (n = 733) and 8 (n = 786) years. Additionally, we applied a literature-based candidate approach for antioxidant and anti-inflammatory genes. To assess influence of exposure at the transcriptomics level, we related mRNA expression in blood cells to NO2 exposure in 4- (n = 111) and 16-year-olds (n = 239). Results: We found epigenome-wide significant associations [false discovery rate (FDR) p < 0.05] between maternal NO2 exposure during pregnancy and DNA methylation in newborns for 3 CpG sites in mitochondria-related genes: cg12283362 (LONP1), cg24172570 (3.8 kbp upstream of HIBADH), and cg08973675 (SLC25A28). The associations with cg08973675 methylation were also significant in the older children. Further analysis of antioxidant and anti-inflammatory genes revealed differentially methylated CpGs in CAT and TPO in newborns (FDR p < 0.05). NO2 exposure at the time of biosampling in childhood had a significant impact on CAT and TPO expression. Conclusions: NO2 exposure during pregnancy was associated with differential offspring DNA methylation in mitochondria-related genes. Exposure to NO2 was also linked to differential methylation as well as expression of genes involved in antioxidant defense pathways. Citation: Gruzieva O, Xu CJ, Breton CV, Annesi-Maesano I, Antó JM, Auffray C, Ballereau S, Bellander T, Bousquet J, Bustamante M, Charles MA, de Kluizenaar Y, den Dekker

Changes in Neuroticism Following Trauma Exposure

PubMed Central

Ogle, Christin M.; Rubin, David C.; Siegler, Ilene C.

2014-01-01

Objective Using longitudinal data, the present study examined change in midlife neuroticism following trauma exposure. Method Our primary analyses included 670 participants (M age = 60.55, 65.22% male, 99.70% Caucasian) who completed the NEO Personality Inventory at mean age 42 and 50 and reported their lifetime exposure to traumatic events approximately 10 years later. Results No differences in pre-and post-trauma neuroticism scores were found among individuals who experienced all of their lifetime traumas in the interval between the personality assessments. Results were instead consistent with normative age-related declines in neuroticism throughout adulthood. Furthermore, longitudinal changes in neuroticism scores did not differ between individuals with and without histories of midlife trauma exposure. Examination of change in neuroticism following life-threatening traumas yielded a comparable pattern of results. Analysis of facet-level scores largely replicated findings from the domain scores. Supplemental analyses indicated that individuals exposed to life-threatening traumas in childhood or adolescence reported higher midlife neuroticism than individuals who experienced severe traumas in adulthood. Conclusions Overall, our findings suggest that neuroticism does not reliably change following exposure to traumatic events in middle adulthood. Life-threatening traumatic events encountered early in life may have a more pronounced impact on adulthood personality than recent traumatic events. PMID:23550961

Initial implementation of a comparative data analysis ontology.

PubMed

Prosdocimi, Francisco; Chisham, Brandon; Pontelli, Enrico; Thompson, Julie D; Stoltzfus, Arlin

2009-07-03

Comparative analysis is used throughout biology. When entities under comparison (e.g. proteins, genomes, species) are related by descent, evolutionary theory provides a framework that, in principle, allows N-ary comparisons of entities, while controlling for non-independence due to relatedness. Powerful software tools exist for specialized applications of this approach, yet it remains under-utilized in the absence of a unifying informatics infrastructure. A key step in developing such an infrastructure is the definition of a formal ontology. The analysis of use cases and existing formalisms suggests that a significant component of evolutionary analysis involves a core problem of inferring a character history, relying on key concepts: "Operational Taxonomic Units" (OTUs), representing the entities to be compared; "character-state data" representing the observations compared among OTUs; "phylogenetic tree", representing the historical path of evolution among the entities; and "transitions", the inferred evolutionary changes in states of characters that account for observations. Using the Web Ontology Language (OWL), we have defined these and other fundamental concepts in a Comparative Data Analysis Ontology (CDAO). CDAO has been evaluated for its ability to represent token data sets and to support simple forms of reasoning. With further development, CDAO will provide a basis for tools (for semantic transformation, data retrieval, validation, integration, etc.) that make it easier for software developers and biomedical researchers to apply evolutionary methods of inference to diverse types of data, so as to integrate this powerful framework for reasoning into their research.

Do Gender and Exposure to Interparental Violence Moderate the Stability of Teen Dating Violence?: Latent Transition Analysis.

PubMed

Choi, Hye Jeong; Temple, Jeff R

2016-04-01

This study investigates the development, change, and stability of teen dating violence (TDV) victimization over time. Specifically, we identify distinct subgroups of adolescents based on past-year TDV victimization, whether adolescents change victimization statuses over time (e.g., from psychological victimization to physical victimization), and how exposure to interparental violence and gender influence the prevalence and stability of TDV statuses. Adolescents (N=1,042) from 7 public high schools in Texas participated in this longitudinal study. The Conflict in Adolescent Dating Relationships Inventory (CADRI) (Wolfe et al., Psychological Assessment, 13(2), 277-293, 2001) was used to identify victimization statuses. Latent Transition Analysis (LTA) with measurement invariance was used to examine transition probability of an individual's latent status at Wave3 or Wave4 given his or her latent status at Wave2 or Wave3. Gender and exposure to interparental violence was included as moderators in the LTA. Three statuses of TDV victimization were identified: (1) non-victims; (2) emotional/verbal victims; and (3) physical/psychological victims. LTA showed that the majority of adolescents stayed in the same status over time; however, female youth exposed to interparental violence were more likely to move from a less to more severe status over time compared to non-exposed youth. This is among the first study to identify subgroups of TDV victimization and to examine the stability of group membership over time. Female youth exposed to interparental violence were more likely to remain in or move into a violent relationship compared to unexposed youth.

Characterizing risk factors for pediatric lamp oil product exposures.

PubMed

Sheikh, S; Chang, A; Kieszak, S; Law, R; Bennett, H K W; Ernst, E; Bond, G R; Spiller, H A; Schurz-Rogers, H; Chu, A; Bronstein, A C; Schier, J G

2013-11-01

Poisonings from lamp oil ingestion continue to occur worldwide among the pediatric population despite preventive measures such as restricted sale of colored and scented lamp oils. This suggests that optimal prevention practices for unintentional pediatric exposures to lamp oil have yet to be identified and/or properly implemented. To characterize demographic, health data, and potential risk factors associated with reported exposures to lamp oil by callers to poison centers (PCs) in the US and discuss their public health implications. This was a two part study in which the first part included characterizing all exposures to a lamp oil product reported to the National Poison Data System (NPDS) with regard to demographics, exposure, health, and outcome data from 1/1/2000 to 12/31/2010. Regional penetrance was calculated using NPDS data by grouping states into four regions and dividing the number of exposure calls by pediatric population per region (from the 2000 US census). Temporal analyses were performed on NPDS data by comparing number of exposures by season and around the July 4th holiday. Poisson regression was used to model the count of exposures for these analyses. In the second part of this project, in order to identify risk factors we conducted a telephone-based survey to the parents of children from five PCs in five different states. The 10 most recent lamp oil product exposure calls for each poison center were systematically selected for inclusion. Calls in which a parent or guardian witnessed a pediatric lamp oil product ingestion were eligible for inclusion. Data on demographics, exposure information, behavioral traits, and health were collected. A descriptive analysis was performed and Fisher's exact test was used to evaluate associations between variables. All analyses were conducted using SAS v9.3. Among NPDS data, 2 years was the most common patient age reported and states in the Midwestern region had the highest numbers of exposure calls compared to

Personal exposure to mixtures of volatile organic compounds: modeling and further analysis of the RIOPA data.

PubMed

Batterman, Stuart; Su, Feng-Chiao; Li, Shi; Mukherjee, Bhramar; Jia, Chunrong

2014-06-01

affect VOC exposures, many personal, environmental, and socioeconomic determinants remain to be identified, and the significance and applicability of the determinants reported in the literature are uncertain. To help answer these unresolved questions and overcome limitations of previous analyses, this project used several novel and powerful statistical modeling and analysis techniques and two large data sets. The overall objectives of this project were (1) to identify and characterize exposure distributions (including extreme values), (2) evaluate mixtures (including dependencies), and (3) identify determinants of VOC exposure. METHODS VOC data were drawn from two large data sets: the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study (1999-2001) and the National Health and Nutrition Examination Survey (NHANES; 1999-2000). The RIOPA study used a convenience sample to collect outdoor, indoor, and personal exposure measurements in three cities (Elizabeth, NJ; Houston, TX; Los Angeles, CA). In each city, approximately 100 households with adults and children who did not smoke were sampled twice for 18 VOCs. In addition, information about 500 variables associated with exposure was collected. The NHANES used a nationally representative sample and included personal VOC measurements for 851 participants. NHANES sampled 10 VOCs in common with RIOPA. Both studies used similar sampling methods and study periods. Specific Aim 1. To estimate and model extreme value exposures, extreme value distribution models were fitted to the top 10% and 5% of VOC exposures. Health risks were estimated for individual VOCs and for three VOC mixtures. Simulated extreme value data sets, generated for each VOC and for fitted extreme value and lognormal distributions, were compared with measured concentrations (RIOPA observations) to evaluate each model's goodness of fit. Mixture distributions were fitted with the conventional finite mixture of normal distributions and the semi

Comparative susceptibility of Atlantic salmon, lake trout and rainbow trout to Myxobolus cerebralis in controlled laboratory exposures

USGS Publications Warehouse

Blazer, V.S.; Densmore, Christine L.; Schill, W.B.; Cartwright, Deborah D.; Page, S.J.

2004-01-01

The susceptibility of lake trout Salvelinus namaycush, rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar to Myxobolus cerebralis, the causative agent of whirling disease, was compared in controlled laboratory exposures. A total of 450 (225 for each dose) fry for each species were exposed to a low (200 spores per fish) or high (2000 spores per fish) dose of the infective triactinomyxon. At 22 wk post-exposure, 60 fish from each group, as well as controls for each species, were examined for clinical signs (whirling behavior, blacktail, deformed heads and skeletal deformities), microscopic lesions, and presence of spores. Rainbow trout were highly susceptible to infection, with 100% being positive for spores and with microscopic pathological changes in both exposure groups. Rainbow trout were the only species to show whirling behavior and blacktail. Atlantic salmon were less susceptible, with only 44 and 61% being positive for spores, respectively, in the low and high dose groups, while 68 and 75%, respectively, had microscopic pathology associated with cartilage damage. Rainbow trout heads contained mean spore concentrations of 2.2 (low dose) or 4.0 (high dose) ?? 106 spores g tissue-1. The means for positive Atlantic salmon (not including zero values) were 1.7 (low) and 7.4 (high) ?? 104 spores g tissue-1. Lake trout showed no clinical signs of infection, were negative for spores in both groups and showed no histopathological signs of M. cerebralis infection.

Comparative susceptibility of Atlantic salmon, lake trout and rainbow trout to Myxobolus cerebralis in controlled laboratory exposures.

PubMed

Blazer, V S; Densmore, C L; Schill, W B; Cartwright, D D; Page, S J

2004-01-28

The susceptibility of lake trout Salvelinus namaycush, rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar to Myxobolus cerebralis, the causative agent of whirling disease, was compared in controlled laboratory exposures. A total of 450 (225 for each dose) fry for each species were exposed to a low (200 spores per fish) or high (2000 spores per fish) dose of the infective triactinomyxon. At 22 wk post-exposure, 60 fish from each group, as well as controls for each species, were examined for clinical signs (whirling behavior, blacktail, deformed heads and skeletal deformities), microscopic lesions, and presence of spores. Rainbow trout were highly susceptible to infection, with 100% being positive for spores and with microscopic pathological changes in both exposure groups. Rainbow trout were the only species to show whirling behavior and blacktail. Atlantic salmon were less susceptible, with only 44 and 61% being positive for spores, respectively, in the low and high dose groups, while 68 and 75%, respectively, had microscopic pathology associated with cartilage damage. Rainbow trout heads contained mean spore concentrations of 2.2 (low dose) or 4.0 (high dose) x 10(6) spores g tissue(-1). The means for positive Atlantic salmon (not including zero values) were 1.7 (low) and 7.4 (high) x 10(4) spores g tissue(-1). Lake trout showed no clinical signs of infection, were negative for spores in both groups and showed no histopathological signs of M. cerebralis infection.

Use of Markov Chain Monte Carlo analysis with a physiologically-based pharmacokinetic model of methylmercury to estimate exposures in US women of childbearing age.

PubMed

Allen, Bruce C; Hack, C Eric; Clewell, Harvey J

2007-08-01

A Bayesian approach, implemented using Markov Chain Monte Carlo (MCMC) analysis, was applied with a physiologically-based pharmacokinetic (PBPK) model of methylmercury (MeHg) to evaluate the variability of MeHg exposure in women of childbearing age in the U.S. population. The analysis made use of the newly available National Health and Nutrition Survey (NHANES) blood and hair mercury concentration data for women of age 16-49 years (sample size, 1,582). Bayesian analysis was performed to estimate the population variability in MeHg exposure (daily ingestion rate) implied by the variation in blood and hair concentrations of mercury in the NHANES database. The measured variability in the NHANES blood and hair data represents the result of a process that includes interindividual variation in exposure to MeHg and interindividual variation in the pharmacokinetics (distribution, clearance) of MeHg. The PBPK model includes a number of pharmacokinetic parameters (e.g., tissue volumes, partition coefficients, rate constants for metabolism and elimination) that can vary from individual to individual within the subpopulation of interest. Using MCMC analysis, it was possible to combine prior distributions of the PBPK model parameters with the NHANES blood and hair data, as well as with kinetic data from controlled human exposures to MeHg, to derive posterior distributions that refine the estimates of both the population exposure distribution and the pharmacokinetic parameters. In general, based on the populations surveyed by NHANES, the results of the MCMC analysis indicate that a small fraction, less than 1%, of the U.S. population of women of childbearing age may have mercury exposures greater than the EPA RfD for MeHg of 0.1 microg/kg/day, and that there are few, if any, exposures greater than the ATSDR MRL of 0.3 microg/kg/day. The analysis also indicates that typical exposures may be greater than previously estimated from food consumption surveys, but that the variability

Comparative genome analysis in the integrated microbial genomes (IMG) system.

PubMed

Markowitz, Victor M; Kyrpides, Nikos C

2007-01-01

Comparative genome analysis is critical for the effective exploration of a rapidly growing number of complete and draft sequences for microbial genomes. The Integrated Microbial Genomes (IMG) system (img.jgi.doe.gov) has been developed as a community resource that provides support for comparative analysis of microbial genomes in an integrated context. IMG allows users to navigate the multidimensional microbial genome data space and focus their analysis on a subset of genes, genomes, and functions of interest. IMG provides graphical viewers, summaries, and occurrence profile tools for comparing genes, pathways, and functions (terms) across specific genomes. Genes can be further examined using gene neighborhoods and compared with sequence alignment tools.

Comparative Risks of Cancer from Drywall Finishing Based on Stochastic Modeling of Cumulative Exposures to Respirable Dusts and Chrysotile Asbestos Fibers.

PubMed

Boelter, Fred W; Xia, Yulin; Dell, Linda

2015-05-01

Sanding joint compounds is a dusty activity and exposures are not well characterized. Until the mid 1970s, asbestos-containing joint compounds were used by some people such that sanding could emit dust and asbestos fibers. We estimated the distribution of 8-h TWA concentrations and cumulative exposures to respirable dusts and chrysotile asbestos fibers for four worker groups: (1) drywall specialists, (2) generalists, (3) tradespersons who are bystanders to drywall finishing, and (4) do-it-yourselfers (DIYers). Data collected through a survey of experienced contractors, direct field observations, and literature were used to develop prototypical exposure scenarios for each worker group. To these exposure scenarios, we applied a previously developed semi-empirical mathematical model that predicts area as well as personal breathing zone respirable dust concentrations. An empirical factor was used to estimate chrysotile fiber concentrations from respirable dust concentrations. On a task basis, we found mean 8-h TWA concentrations of respirable dust and chrysotile fibers are numerically highest for specialists, followed by generalists, DIYers, and bystander tradespersons; these concentrations are estimated to be in excess of the respective current but not historical Threshold Limit Values. Due to differences in frequency of activities, annual cumulative exposures are highest for specialists, followed by generalists, bystander tradespersons, and DIYers. Cumulative exposure estimates for chrysotile fibers from drywall finishing are expected to result in few, if any, mesothelioma or excess lung cancer deaths according to recently published risk assessments. Given the dustiness of drywall finishing, we recommend diligence in the use of readily available source controls. © 2014 Society for Risk Analysis.

Statistical correlation analysis for comparing vibration data from test and analysis

NASA Technical Reports Server (NTRS)

Butler, T. G.; Strang, R. F.; Purves, L. R.; Hershfeld, D. J.

1986-01-01

A theory was developed to compare vibration modes obtained by NASTRAN analysis with those obtained experimentally. Because many more analytical modes can be obtained than experimental modes, the analytical set was treated as expansion functions for putting both sources in comparative form. The dimensional symmetry was developed for three general cases: nonsymmetric whole model compared with a nonsymmetric whole structural test, symmetric analytical portion compared with a symmetric experimental portion, and analytical symmetric portion with a whole experimental test. The theory was coded and a statistical correlation program was installed as a utility. The theory is established with small classical structures.

Association between perfluoroalkyl substances exposure and thyroid function in adults: A meta-analysis

PubMed Central

Oh, Byung-Chul; Jung, Dawoon; Ji, Kyunghee; Choi, Kyungho

2018-01-01

Objective Many people are exposed to perfluoroalkyl substances (PFASs) because these substances are widely used as industrial products. Although epidemiological studies suggest that PFASs can disrupt thyroid hormones, the association between PFAS exposure and thyroid function remains inconclusive. Therefore, we performed a comprehensive meta-analysis to investigate the association between PFASs exposure and thyroid hormones. Methods We searched medical literature databases for articles on the association between PFASs–perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS)–and thyroid hormone levels in adults. Twelve articles were included in the meta-analysis, and the pooled z values were calculated with correlation or regression coefficients. Results The blood PFOS concentration was positively correlated with free T4. The pooled z value was 0.05 (95% confidence interval (CI): 0.03, 0.08). PFOS was negatively correlated with total T4 and total T3 when excluding outlier studies. In a subgroup analysis stratified by mean PFOS concentration, PFOS was observed to be positively associated with free T4 and TSH and negatively associated with total T3 in the intermediate concentration group (8–16 ng/mL). PFOA concentration was negatively correlated with total T4 (z value, -0.06; 95% CI: -0.09, -0.03) after omitting one outlier study. PFHxS also showed a negative correlation with total T4 (z value, -0.04; 95% CI: -0.07, -0.01). A subgroup analysis of pregnant women showed that there was no association between PFASs and thyroid hormones. Conclusions Our meta-analysis suggests that PFASs are negatively associated with total T4, and their effect can be different depending on the PFAS concentration. PMID:29746532

Lifetime fluoridation exposure and dental caries experience in a military population.

PubMed

Mahoney, Gregory; Slade, Gary D; Kitchener, Scott; Barnett, Adrian

2008-12-01

While there is good evidence of caries-preventive benefits of fluoride in drinking water among children and adolescents, there is little information about effectiveness of water fluoridation among adults. To determine whether exposure to fluoride in drinking water is associated with caries experience in Australian Defence Force (ADF) personnel. Cross-sectional study of 876 deployable ADF personnel aged 17-56 years. At each person's mandatory annual dental examination, military dentists recorded the number of decayed, missing and filled teeth (DMFT) using visual, tactile and radiographic criteria. Participants also completed a questionnaire, listing residential locations in each year from 1964 to 2003. People were classified into four categories according to the percentage of their lifetime living in places with fluoridated water: <10%, 10% to <50%, 50% to <90% and > or =90%. Mean DMFT was compared among those categories of fluoridation exposure and the association was evaluated statistically using analysis of variance to adjust for age, sex, years of service and rank. Without adjustment for confounders, the mean DMFT (+/-95% confidence interval) was 6.3 +/- 0.8 for <10% fluoridation exposure, 7.8 +/- 0.8 for 10% to <50% exposure, 7.5 +/- 0.7 for 50% to <90% exposure and 4.6 +/- 0.6 for > or =90% exposure (P < 0.01). However, age was inversely associated with mean DMFT and in the <10% exposure group, 91% of people were aged <35 years. Service rank was also significantly associated with both fluoridation exposure and DMFT. After adjustment for all covariates, mean DMFT was 24% lower among people in the two groups with > or =50% exposure compared with the <10% exposure group. Degree of lifetime exposure to fluoridated drinking water was inversely associated with DMFT in a dose-response manner among this adult military population.

CAD-based stand-alone spacecraft radiation exposure analysis system: An application of the early man-tended Space Station

NASA Technical Reports Server (NTRS)

Appleby, M. H.; Golightly, M. J.; Hardy, A. C.

1993-01-01

Major improvements have been completed in the approach to analyses and simulation of spacecraft radiation shielding and exposure. A computer-aided design (CAD)-based system has been developed for determining the amount of shielding provided by a spacecraft and simulating transmission of an incident radiation environment to any point within or external to the vehicle. Shielding analysis is performed using a customized ray-tracing subroutine contained within a standard engineering modeling software package. This improved shielding analysis technique has been used in several vehicle design programs such as a Mars transfer habitat, pressurized lunar rover, and the redesigned international Space Station. Results of analysis performed for the Space Station astronaut exposure assessment are provided to demonastrate the applicability and versatility of the system.

AC field exposure study: human exposure to 60-Hz electric fields

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

Silva, J.M.

1985-04-01

The objective of this study was to develop a method of estimating human exposure to the 60 Hz electric fields created by transmission lines. The Activity Systems Model simulates human activities in a variety of situations where exposure to electric fields is possible. The model combines maps of electric fields, activity maps, and experimentally determined activity factors to provide histograms of time spent in electric fields of various strengths in the course of agricultural, recreational, and domestic activities. For corroboration, the study team measured actual human exposure at locations across the United States near transmission lines ranging in voltage frommore » 115 to 1200 kV. The data were collected with a specially designed vest that measures exposure. These data demonstrate the accuracy of the exposure model presented in this report and revealed that most exposure time is spent in fields of magnitudes similar to many household situations. The report provides annual exposure estimates for human activities near transmission lines and in the home and compares them with exposure data from typical laboratory animal experiments. For one exposure index, the cumulative product of time and electric field, exposure during some of the laboratory animal experiments is two to four orders of magnitude greater than cumulative exposure for a human during one year of outdoor work on a farm crossed by a transmission line.« less

Spatio-temporal earthquake risk assessment for the Lisbon Metropolitan Area - A contribution to improving standard methods of population exposure and vulnerability analysis

NASA Astrophysics Data System (ADS)

Freire, Sérgio; Aubrecht, Christoph

2010-05-01