Science.gov

Sample records for accurately assess exposure

  1. Sunlight exposure assessment: can we accurately assess vitamin D exposure from sunlight questionnaires?

    PubMed

    McCarty, Catherine A

    2008-04-01

    The purpose of this review is to summarize the peer-reviewed literature in relation to sunlight exposure assessment and the validity of using sunlight exposure questionnaires to quantify vitamin D status. There is greater variability in personal ultraviolet (UV) light exposure as the result of personal behavior than as the result of ambient UV light exposure. Although statistically significant, the correlation coefficients for the relation between personal report of sun exposure and ambient UV light measured by dosimetry (assessment of radiation dose) are relatively low. Moreover, the few studies to assess the relation between sunlight measures and serum 25-hydroxyvitamin D show low correlations. These low correlations may not be surprising given that personal factors like melanin content in skin and age also influence cutaneous synthesis of vitamin D. In summary, sunlight exposure questionnaires currently provide imprecise estimates of vitamin D status. Research should be directed to develop more objective, nonintrusive, and economical measures of sunlight exposure to quantify personal vitamin D status.

  2. Integrated Exposure Assessment Monitoring.

    ERIC Educational Resources Information Center

    Behar, Joseph V.; And Others

    1979-01-01

    Integrated Exposure Assessment Monitoring is the coordination of environmental (air, water, land, and crops) monitoring networks to collect systematically pollutant exposure data for a specific receptor, usually man. (Author/BB)

  3. Dermal exposure assessment.

    PubMed

    Schneider, T; Cherrie, J W; Vermeulen, R; Kromhout, H

    2000-10-01

    Assessing dermal exposure is a complex task. Even the most commonly used methods face fundamental problems and there are large gaps in the documentation and validation of sampling methods. Still larger uncertainties exist regarding strategies for measurement. We propose a strategy based on a conceptual model and which draws on the considerable insight gained for airborne contaminants, including EN 689 for assessing exposure by inhalation. The vast amount of air sampling data has provided good insight into the statistical properties of short-term and long-term exposure levels, which is essential for designing cost-effective exposure studies. For surface and skin contaminants an understanding of the distribution types and parameter values is only beginning to emerge. Transport rates away from the skin contaminant layer determine the 'memory' of a dermal sample and measurement principles are proposed depending on these rates. It is argued that uptake is the ultimate dermal exposure metric for risk assessment and should be the basis for devising dermal occupational exposure limits.

  4. Asbestos Exposure Assessment Database

    NASA Technical Reports Server (NTRS)

    Arcot, Divya K.

    2010-01-01

    Exposure to particular hazardous materials in a work environment is dangerous to the employees who work directly with or around the materials as well as those who come in contact with them indirectly. In order to maintain a national standard for safe working environments and protect worker health, the Occupational Safety and Health Administration (OSHA) has set forth numerous precautionary regulations. NASA has been proactive in adhering to these regulations by implementing standards which are often stricter than regulation limits and administering frequent health risk assessments. The primary objective of this project is to create the infrastructure for an Asbestos Exposure Assessment Database specific to NASA Johnson Space Center (JSC) which will compile all of the exposure assessment data into a well-organized, navigable format. The data includes Sample Types, Samples Durations, Crafts of those from whom samples were collected, Job Performance Requirements (JPR) numbers, Phased Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM) results and qualifiers, Personal Protective Equipment (PPE), and names of industrial hygienists who performed the monitoring. This database will allow NASA to provide OSHA with specific information demonstrating that JSC s work procedures are protective enough to minimize the risk of future disease from the exposures. The data has been collected by the NASA contractors Computer Sciences Corporation (CSC) and Wyle Laboratories. The personal exposure samples were collected from devices worn by laborers working at JSC and by building occupants located in asbestos-containing buildings.

  5. Exposure Assessment Tools by Approaches

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  6. Exposure Assessment Tools by Routes

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  7. Exposure Assessment Tools by Media

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  8. Measurement error in air pollution exposure assessment.

    PubMed

    Navidi, W; Lurmann, F

    1995-01-01

    The exposure of an individual to an air pollutant can be assessed indirectly, with a "microenvironmental" approach, or directly with a personal sampler. Both methods of assessment are subject to measurement error, which can cause considerable bias in estimates of health effects. If the exposure estimates are unbiased and the measurement error is nondifferential, the bias in a linear model can be corrected when the variance of the measurement error is known. Unless the measurement error is quite large, estimates of health effects based on individual exposures appear to be more accurate than those based on ambient levels.

  9. 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...

  10. HUMAN EXPOSURE ASSESSMENT USING IMMUNOASSAY

    EPA Science Inventory

    The National Exposure Research Laboratory-Las Vegas is developing analytical methods for human exposure assessment studies. Critical exposure studies generate a large number of samples which must be analyzed in a reliable, cost-effective and timely manner. TCP (3,5,6-trichlor...

  11. Change in BMI Accurately Predicted by Social Exposure to Acquaintances

    PubMed Central

    Oloritun, Rahman O.; Ouarda, Taha B. M. J.; Moturu, Sai; Madan, Anmol; Pentland, Alex (Sandy); Khayal, Inas

    2013-01-01

    Research has mostly focused on obesity and not on processes of BMI change more generally, although these may be key factors that lead to obesity. Studies have suggested that obesity is affected by social ties. However these studies used survey based data collection techniques that may be biased toward select only close friends and relatives. In this study, mobile phone sensing techniques were used to routinely capture social interaction data in an undergraduate dorm. By automating the capture of social interaction data, the limitations of self-reported social exposure data are avoided. This study attempts to understand and develop a model that best describes the change in BMI using social interaction data. We evaluated a cohort of 42 college students in a co-located university dorm, automatically captured via mobile phones and survey based health-related information. We determined the most predictive variables for change in BMI using the least absolute shrinkage and selection operator (LASSO) method. The selected variables, with gender, healthy diet category, and ability to manage stress, were used to build multiple linear regression models that estimate the effect of exposure and individual factors on change in BMI. We identified the best model using Akaike Information Criterion (AIC) and R2. This study found a model that explains 68% (p<0.0001) of the variation in change in BMI. The model combined social interaction data, especially from acquaintances, and personal health-related information to explain change in BMI. This is the first study taking into account both interactions with different levels of social interaction and personal health-related information. Social interactions with acquaintances accounted for more than half the variation in change in BMI. This suggests the importance of not only individual health information but also the significance of social interactions with people we are exposed to, even people we may not consider as close friends. PMID

  12. Accurate measurement of RF exposure from emerging wireless communication systems

    NASA Astrophysics Data System (ADS)

    Letertre, Thierry; Monebhurrun, Vikass; Toffano, Zeno

    2013-04-01

    Isotropic broadband probes or spectrum analyzers (SAs) may be used for the measurement of rapidly varying electromagnetic fields generated by emerging wireless communication systems. In this paper this problematic is investigated by comparing the responses measured by two different isotropic broadband probes typically used to perform electric field (E-field) evaluations. The broadband probes are submitted to signals with variable duty cycles (DC) and crest factors (CF) either with or without Orthogonal Frequency Division Multiplexing (OFDM) modulation but with the same root-mean-square (RMS) power. The two probes do not provide accurate enough results for deterministic signals such as Worldwide Interoperability for Microwave Access (WIMAX) or Long Term Evolution (LTE) as well as for non-deterministic signals such as Wireless Fidelity (WiFi). The legacy measurement protocols should be adapted to cope for the emerging wireless communication technologies based on the OFDM modulation scheme. This is not easily achieved except when the statistics of the RF emission are well known. In this case the measurement errors are shown to be systematic and a correction factor or calibration can be applied to obtain a good approximation of the total RMS power.

  13. Personal Exposure Monitoring Wearing Protocol Compliance: An Initial Assessment of Quantitative Measurements

    EPA Science Inventory

    Personal exposure sampling provides the most accurate and representative assessment of exposure to a pollutant, but only if measures are implemented to minimize exposure misclassification and reduce confounders that may cause misinterpretation of the collected data. Poor complian...

  14. Foresight begins with FMEA. Delivering accurate risk assessments.

    PubMed

    Passey, R D

    1999-03-01

    If sufficient factors are taken into account and two- or three-stage analysis is employed, failure mode and effect analysis represents an excellent technique for delivering accurate risk assessments for products and processes, and for relating them to legal liability. This article describes a format that facilitates easy interpretation.

  15. Environmental tobacco smoke exposure assessment

    SciTech Connect

    Guerin, M.R.

    1993-01-01

    Environmental tobacco smoke (ETS) is the material released into the environment as tobacco products are smoked. Cigarettes, pipes, and cigars all produce ETS but the term has become all but synonymous with indoor air contamination by cigarette smoking. This is because cigarettes are by far the most commonly consumed tobacco product and because the principal human exposure occurs indoors. Exposure to ETS is variously termed as passive smoking, involuntary smoking, and as exposure to second-hand smoke. Considerable progress has been made toward a better understanding of ETS exposure. Strengths and limitations of various measures of exposure are better understood and much data has been generated on the quantities of many ETS-constituents in many indoor environments. The properties of ETS, methods for its measurement in indoor air, and many results of field studies have recently been reviewed by the author. The recent EPA report includes a major treatment of exposure estimation including air concentrations, questionnaires, and biomarkers. This paper discusses approaches to exposure assessment and summarizes data on indoor air concentrations of ETS-constituents.

  16. Environmental tobacco smoke exposure assessment

    SciTech Connect

    Guerin, M.R.

    1993-06-01

    Environmental tobacco smoke (ETS) is the material released into the environment as tobacco products are smoked. Cigarettes, pipes, and cigars all produce ETS but the term has become all but synonymous with indoor air contamination by cigarette smoking. This is because cigarettes are by far the most commonly consumed tobacco product and because the principal human exposure occurs indoors. Exposure to ETS is variously termed as passive smoking, involuntary smoking, and as exposure to second-hand smoke. Considerable progress has been made toward a better understanding of ETS exposure. Strengths and limitations of various measures of exposure are better understood and much data has been generated on the quantities of many ETS-constituents in many indoor environments. The properties of ETS, methods for its measurement in indoor air, and many results of field studies have recently been reviewed by the author. The recent EPA report includes a major treatment of exposure estimation including air concentrations, questionnaires, and biomarkers. This paper discusses approaches to exposure assessment and summarizes data on indoor air concentrations of ETS-constituents.

  17. INDOOR AEROSOLS AND EXPOSURE ASSESSMENT

    EPA Science Inventory

    This chapter provides an overview of both indoor aerosol concentration measurements, and the considerations for assessment of exposure to aerosols in non-occupational settings. The fixed-location measurements of concentration at an outdoor location, while commuting inside an a...

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

    PubMed

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

    2015-08-11

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

  19. 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...

  20. CT Scan Method Accurately Assesses Humeral Head Retroversion

    PubMed Central

    Boileau, P.; Mazzoleni, N.; Walch, G.; Urien, J. P.

    2008-01-01

    Humeral head retroversion is not well described with the literature controversial regarding accuracy of measurement methods and ranges of normal values. We therefore determined normal humeral head retroversion and assessed the measurement methods. We measured retroversion in 65 cadaveric humeri, including 52 paired specimens, using four methods: radiographic, computed tomography (CT) scan, computer-assisted, and direct methods. We also assessed the distance between the humeral head central axis and the bicipital groove. CT scan methods accurately measure humeral head retroversion, while radiographic methods do not. The retroversion with respect to the transepicondylar axis was 17.9° and 21.5° with respect to the trochlear tangent axis. The difference between the right and left humeri was 8.9°. The distance between the central axis of the humeral head and the bicipital groove was 7.0 mm and was consistent between right and left humeri. Humeral head retroversion may be most accurately obtained using the patient’s own anatomic landmarks or, if not, identifiable retroversion as measured by those landmarks on contralateral side or the bicipital groove. PMID:18264854

  1. Response to “Accurate Risk-Based Chemical Screening Relies on Robust Exposure Estimates”

    EPA Science Inventory

    This is a correspondence (letter to the editor) with reference to comments by Rudel and Perovich on the article "Integration of Dosimetry, Exposure, and High-Throughput Screening Data in Chemical Toxicity Assessment". Article Reference: SI # 238882

  2. Exposure Assessment Tools by Routes - Dermal

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  3. Exposure Assessment Tools by Media - Consumer Products

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  4. Exposure Assessment Tools by Chemical Classes - Nanomaterials

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  5. Exposure Assessment Tools by Media - Food

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  6. Exposure Assessment Tools by Media - Aquatic Biota

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  7. Exposure Assessment Tools by Routes - Inhalation

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  8. Exposure Assessment Tools by Chemical Classes - Pesticides

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  9. Exposure Assessment Tools by Chemical Classes

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  10. Exposure Assessment Tools by Lifestages and Populations

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  11. Exposure Assessment Tools by Routes - Ingestion

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  12. Exposure Assessment Tools by Tiers and Types

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  13. Exposure Assessment Tools by Media - Air

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  14. A novel sulfur mustard (HD) vapor inhalation exposure system for accurate inhaled dose delivery

    PubMed Central

    Perry, Mark R.; Benson, Eric M.; Kohne, Jonathon W.; Plahovinsak, Jennifer L.; Babin, Michael C.; Platoff, Gennady E.; Yeung, David T.

    2014-01-01

    Introduction A custom designed HD exposure system was used to deliver controlled inhaled doses to an animal model through an endotracheal tube. Methods Target HD vapor challenges were generated by a temperature controlled bubbler/aerosol trap, while concentration was monitored near real-time by gas chromatography. Animal breathing parameters were monitored real-time by an in-line pneumotach, pressure transducer, and Buxco pulmonary analysis computer/software. For each exposure, the challenge atmosphere was allowed to stabilize at the desired concentration while the anesthetized animal was provided humidity controlled clean air. Once the target concentration was achieved and stable, a portion of the challenge atmosphere was drawn past the endotracheal tube, where the animal inhaled the exposure ad libitum. During the exposure, HD vapor concentration and animal weight were used to calculate the needed inhaled volume to achieve the target inhaled dose (μg/kg). The exposures were halted when the inhaled volume was achieved. Results The exposure system successfully controlled HD concentrations from 22.2 to 278 mg/m3 and accurately delivered inhaled doses between 49.3 and 1120 μg/kg with actual administered doses being within 4% of the target level. Discussion This exposure system administers specific HD inhaled doses to evaluate physiological effects and for evaluation of potential medical countermeasure treatments. PMID:25291290

  15. Economic Value Of Accurate Assessments Of Hydrological Uncertainty

    NASA Astrophysics Data System (ADS)

    Ajami, N. K.; Sunding, D. L.; Hornberger, G. M.

    2008-12-01

    The improvement of techniques to assist in the sustainable management of water resource systems is a crucial issue since our limited resources are under ever increasing pressure. A proper understanding of the sources and effects of uncertainty is needed to achieve goals related to improvements in reliability and sustainability in water resource management and planning. To date, many hydrological techniques have been developed to improve the quality and accuracy of hydrological forecasts and to assess the uncertainty associated with these forecasts. The economic value of improvements in calculations of uncertainty associated with hydrological forecasts from the water supply and demand management perspective remains largely unknown. We first explore the effect of more accurate assessments of hydrological uncertainty on the management of water resources by using an integrated approach to identify and quantify the sources of uncertainty. Subsequently, we analyze the value of a more reliable water supply forecast by studying the change in moments of the distribution of final surface water deliveries. This allows us to calculate the economic value of improving the information about uncertainty provided to stakeholders, especially during drought spells.

  16. Mycotoxins: occurrence, toxicology, and exposure assessment.

    PubMed

    Marin, S; Ramos, A J; Cano-Sancho, G; Sanchis, V

    2013-10-01

    Mycotoxins are abiotic hazards produced by certain fungi that can grow on a variety of crops. Consequently, their prevalence in plant raw materials may be relatively high. The concentration of mycotoxins in finished products is usually lower than in raw materials. In this review, occurrence and toxicology of the main mycotoxins are summarised. Furthermore, methodological approaches for exposure assessment are described. Existing exposure assessments, both through contamination and consumption data and biomarkers of exposure, for the main mycotoxins are also discussed.

  17. Assessment of Human Exposure to ENMs.

    PubMed

    Jiménez, Araceli Sánchez; van Tongeren, Martie

    2017-01-01

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

  18. Exposure Assessment of Livestock Carcass Management ...

    EPA Pesticide Factsheets

    Report This report describes relative exposures and hazards for different livestock carcass management options in the event of a natural disaster. A quantitative exposure assessment by which livestock carcass management options are ranked relative to one another for a hypothetical site setting, a standardized set of environmental conditions (e.g., meteorology), and following a single set of assumptions about how the carcass management options are designed and implemented. These settings, conditions, and assumptions are not necessarily representative of site-specific carcass management efforts. Therefore, the exposure assessment should not be interpreted as estimating levels of chemical and microbial exposure that can be expected to result from the management options evaluated. The intent of the relative rankings is to support scientifically-based livestock carcass management decisions that consider potential hazards to human health, livestock, and the environment. This exposure assessment also provides information to support choices about mitigation measures to minimize or eliminate specific exposure pathways.

  19. Prediction & Assessment of Dermal Exposure

    DTIC Science & Technology

    2007-11-02

    cutaneous exposure requires the transdermal penetration of the chemical. The unique permeation barrier properties of skin ensure that the kinetics of...following dermal exposure, therefore, requires that the rate of skin penetration in man be predictable. The specific aims of the project were: (1) to...derive, from a compre- hensive database of the percutaneous absorption/ penetration literature predictive ("structure-activity") algorithms to calculate a

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

    EPA Science Inventory

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

  1. How accurate are chronic wound assessments using interactive video technology?

    PubMed

    Gardner, S E; Frantz, R A; Specht, J K; Johnson-Mekota, J L; Buresh, K A; Wakefield, B; Flanagan, J

    2001-01-01

    This project examined the accuracy of chronic wound assessments made using an interactive, video telecommunications system (Teledoc 5000, NEC America, Inc., Irving, TX) by comparing a nurse expert's in-person wound assessments with wound assessments made from taped Teledoc sessions. Wound assessments determined the absence or presence of nine wound characteristics instrumental in guiding treatment (e.g., tunneling, undermining, granulation tissue, necrotic tissue, epithelial tissue, purulent exudate, erythema, edema, induration). A sample of 13 paired wound observations was analyzed. The accuracy of the Teledoc technology was examined by calculating the amount of agreement between the in-person assessments and the taped Teledoc assessments for each of the nine characteristics. Agreement for eight of the nine wound characteristic exceeded 75%, suggesting this telehealth medium does not alter wound assessment data, which are essential in guiding treatment decisions. In addition to connecting the remotely based nurse with nursing expertise to improve patient care, telehealth technology seemed to increase the remotely-based nurses' knowledge of wound assessment and treatment as well.

  2. Integrating Exposure into Chemical Alternatives Assessment ...

    EPA Pesticide Factsheets

    Most alternatives assessments (AA) published to date are largely hazard-based rankings, and as such may not represent a fully informed consideration of the advantages and disadvantages of possible alternatives. With an assessment goal of identifying an alternative chemical that is more sustainable, other attributes beyond hazard are also important, including exposure, risk, life-cycle impacts, performance, cost, and social responsibility. Building on the 2014 recommendations by the U.S. National Academy of Sciences to improve AA decisions by including comparative exposure assessment, the HESISustainable Chemical Alternatives Technical Committee, which consists of scientists from academia, industry, government, and NGOs, has developed a qualitative comparative exposure approach. Conducting such a comparison can screen for alternatives that are expected to have a higher exposure potential, which could trigger a higher-tiered, more quantitative exposure assessment on the alternatives being considered. This talk will demonstrate an approach for including chemical- and product-related exposure information in a qualitative AA comparison. Starting from existing hazard AAs, a series of four chemical-product application scenarios were examined to test the concept, to understand the effort required, and to determine the value of exposure data in AA decision-making. The group has developed a classification approach for ingredient and product parameters to support compariso

  3. Drone based measurement system for radiofrequency exposure assessment.

    PubMed

    Joseph, Wout; Aerts, Sam; Vandenbossche, Matthias; Thielens, Arno; Martens, Luc

    2016-03-10

    For the first time, a method to assess radiofrequency (RF) electromagnetic field (EMF) exposure of the general public in real environments with a true free-space antenna system is presented. Using lightweight electronics and multiple antennas placed on a drone, it is possible to perform exposure measurements. This technique will enable researchers to measure three-dimensional RF-EMF exposure patterns accurately in the future and at locations currently difficult to access. A measurement procedure and appropriate measurement settings have been developed. As an application, outdoor measurements are performed as a function of height up to 60 m for Global System for Mobile Communications (GSM) 900 MHz base station exposure. Bioelectromagnetics. © 2016 Wiley Periodicals, Inc.

  4. Numerical system utilising a Monte Carlo calculation method for accurate dose assessment in radiation accidents.

    PubMed

    Takahashi, F; Endo, A

    2007-01-01

    A system utilising radiation transport codes has been developed to derive accurate dose distributions in a human body for radiological accidents. A suitable model is quite essential for a numerical analysis. Therefore, two tools were developed to setup a 'problem-dependent' input file, defining a radiation source and an exposed person to simulate the radiation transport in an accident with the Monte Carlo calculation codes-MCNP and MCNPX. Necessary resources are defined by a dialogue method with a generally used personal computer for both the tools. The tools prepare human body and source models described in the input file format of the employed Monte Carlo codes. The tools were validated for dose assessment in comparison with a past criticality accident and a hypothesized exposure.

  5. Internal Medicine Residents Do Not Accurately Assess Their Medical Knowledge

    ERIC Educational Resources Information Center

    Jones, Roger; Panda, Mukta; Desbiens, Norman

    2008-01-01

    Background: Medical knowledge is essential for appropriate patient care; however, the accuracy of internal medicine (IM) residents' assessment of their medical knowledge is unknown. Methods: IM residents predicted their overall percentile performance 1 week (on average) before and after taking the in-training exam (ITE), an objective and well…

  6. Children's exposure assessment: a review of factors influencing Children's exposure, and the data available to characterize and assess that exposure.

    PubMed Central

    Cohen Hubal, E A; Sheldon, L S; Burke, J M; McCurdy, T R; Berry, M R; Rigas, M L; Zartarian, V G; Freeman, N C

    2000-01-01

    We review the factors influencing children's exposure to environmental contaminants and the data available to characterize and assess that exposure. Children's activity pattern data requirements are demonstrated in the context of the algorithms used to estimate exposure by inhalation, dermal contact, and ingestion. Currently, data on children's exposures and activities are insufficient to adequately assess multimedia exposures to environmental contaminants. As a result, regulators use a series of default assumptions and exposure factors when conducting exposure assessments. Data to reduce uncertainty in the assumptions and exposure estimates are needed to ensure chemicals are regulated appropriately to protect children's health. To improve the database, advancement in the following general areas of research is required: identification of appropriate age/developmental benchmarks for categorizing children in exposure assessment; development and improvement of methods for monitoring children's exposures and activities; collection of activity pattern data for children (especially young children) required to assess exposure by all routes; collection of data on concentrations of environmental contaminants, biomarkers, and transfer coefficients that can be used as inputs to aggregate exposure models. PMID:10856019

  7. Home Circadian Phase Assessments with Measures of Compliance Yield Accurate Dim Light Melatonin Onsets

    PubMed Central

    Burgess, Helen J.; Wyatt, James K.; Park, Margaret; Fogg, Louis F.

    2015-01-01

    Study Objectives: There is a need for the accurate assessment of circadian phase outside of the clinic/laboratory, particularly with the gold standard dim light melatonin onset (DLMO). We tested a novel kit designed to assist in saliva sampling at home for later determination of the DLMO. The home kit includes objective measures of compliance to the requirements for dim light and half-hourly saliva sampling. Design: Participants were randomized to one of two 10-day protocols. Each protocol consisted of two back-to-back home and laboratory phase assessments in counterbalanced order, separated by a 5-day break. Setting: Laboratory or participants' homes. Participants: Thirty-five healthy adults, age 21–62 y. Interventions: N/A. Measurements and Results: Most participants received at least one 30-sec epoch of light > 50 lux during the home phase assessments (average light intensity 4.5 lux), but on average for < 9 min of the required 8.5 h. Most participants collected every saliva sample within 5 min of the scheduled time. Ninety-two percent of home DLMOs were not affected by light > 50 lux or sampling errors. There was no significant difference between the home and laboratory DLMOs (P > 0.05); on average the home DLMOs occurred 9.6 min before the laboratory DLMOs. The home DLMOs were highly correlated with the laboratory DLMOs (r = 0.91, P < 0.001). Conclusions: Participants were reasonably compliant to the home phase assessment procedures. The good agreement between the home and laboratory dim light melatonin onsets (DLMOs) demonstrates that including objective measures of light exposure and sample timing during home saliva sampling can lead to accurate home DLMOs. Clinical Trial Registration: Circadian Phase Assessments at Home, http://clinicaltrials.gov/show/NCT01487252, NCT01487252. Citation: Burgess HJ, Wyatt JK, Park M, Fogg LF. Home circadian phase assessments with measures of compliance yield accurate dim light melatonin onsets. SLEEP 2015;38(6):889–897

  8. Novel Monitor Paradigm for Real-Time Exposure Assessment

    PubMed Central

    Negi, Indira; Tsow, Francis; Tanwar, Kshitiz; Zhang, Lihua; Iglesias, Rodrigo A.; Chen, Cheng; Rai, Anant; Forzani, Erica S.; Tao, Nongjian (NJ)

    2013-01-01

    A wearable monitor that can reliably, accurately and continuously measure personal exposure levels of various toxicants would not only accelerate the current environmental and occupational health and safety studies, but also enable new studies that are not possible with the current monitoring technology. Developing such a monitor has been a difficult challenge, and requires innovative sensing science and creative engineering. We have developed, built and tested a wearable monitor for real-time detection of toxic hydrocarbons and acids in environment. The monitor is low-cost, accurate, and user-friendly. In addition, it can communicate wirelessly with a cell phone in which the monitoring results can be processed, displayed, stored and transmitted to a designated computer. We have validated the functions and performance of the monitor, and carried out field tests with workers involving waste management, fire overhaul, and floor-cleaning activities, as well as with first- and second-hand smokers. The averaged exposure levels are in agreement with those determined by the standard NIOSH methods. The monitor provides accurate and real-time exposure assessment for the workers involving different activities. The real-time and continuous monitoring capability makes it possible to correlate the exposure levels with different activities and changes in the microenvironments. The monitor provides unprecedented real-time information that will help advance occupational safety and environmental health studies. It may also be used to better protect workers from occupational overexposure to toxic molecules. PMID:20551996

  9. Numerical assessment of accurate measurements of laminar flame speed

    NASA Astrophysics Data System (ADS)

    Goulier, Joules; Bizon, Katarzyna; Chaumeix, Nabiha; Meynet, Nicolas; Continillo, Gaetano

    2016-12-01

    In combustion, the laminar flame speed constitutes an important parameter that reflects the chemistry of oxidation for a given fuel, along with its transport and thermal properties. Laminar flame speeds are used (i) in turbulent models used in CFD codes, and (ii) to validate detailed or reduced mechanisms, often derived from studies using ideal reactors and in diluted conditions as in jet stirred reactors and in shock tubes. End-users of such mechanisms need to have an assessment of their capability to predict the correct heat released by combustion in realistic conditions. In this view, the laminar flame speed constitutes a very convenient parameter, and it is then very important to have a good knowledge of the experimental errors involved with its determination. Stationary configurations (Bunsen burners, counter-flow flames, heat flux burners) or moving flames (tubes, spherical vessel, soap bubble) can be used. The spherical expanding flame configuration has recently become popular, since it can be used at high pressures and temperatures. With this method, the flame speed is not measured directly, but derived through the recording of the flame radius. The method used to process the radius history will have an impact on the estimated flame speed. Aim of this work is to propose a way to derive the laminar flame speed from experimental recording of expanding flames, and to assess the error magnitude.

  10. Accurate determination of screw position in treating fifth metatarsal base fractures to shorten radiation exposure time

    PubMed Central

    Wang, Xu; Zhang, Chao; Wang, Chen; Huang, Jia Zhang; Ma, Xin

    2016-01-01

    INTRODUCTION Anatomical markers can help to guide lag screw placement during surgery for internal fixation of fifth metatarsal base fractures. This study aimed to identify the optimal anatomical markers and thus reduce radiation exposure. METHODS A total of 50 patients in Huashan Hospital, Shanghai, China, who underwent oblique foot radiography in the lateral position were randomly selected. The angles between the fifth metatarsal axis and cuboid articular surface were measured to determine the optimal lag screw placement relative to anatomical markers. RESULTS The line connecting the styloid process of the fifth metatarsal base with the second metatarsophalangeal (MTP) joint intersected with the fifth metatarsal base fracture line at an angle of 86.85° ± 5.44°. The line connecting the fifth metatarsal base styloid with the third and fourth MTP joints intersected with the fracture line at angles of 93.28° ± 5.24° and 100.95° ± 5.00°, respectively. The proximal articular surface of the fifth metatarsal base intersected with the line connecting the styloid process of the fifth metatarsal base with the second, third and fourth MTP joints at angles of 24.02° ± 4.77°, 30.79° ± 4.53° and 38.08° ± 4.54°, respectively. CONCLUSION The fifth metatarsal base styloid and third MTP joint can be used as anatomical markers for lag screw placement in fractures involving the fifth tarsometatarsal joint. The connection line, which is normally perpendicular to the fracture line, provides sufficient mechanical stability to facilitate accurate screw placement. The use of these anatomical markers could help to reduce unnecessary radiation exposure for patients and medical staff. PMID:26767892

  11. Text mining for improved exposure assessment

    PubMed Central

    Baker, Simon; Silins, Ilona; Guo, Yufan; Stenius, Ulla; Korhonen, Anna; Berglund, Marika

    2017-01-01

    Chemical exposure assessments are based on information collected via different methods, such as biomonitoring, personal monitoring, environmental monitoring and questionnaires. The vast amount of chemical-specific exposure information available from web-based databases, such as PubMed, is undoubtedly a great asset to the scientific community. However, manual retrieval of relevant published information is an extremely time consuming task and overviewing the data is nearly impossible. Here, we present the development of an automatic classifier for chemical exposure information. First, nearly 3700 abstracts were manually annotated by an expert in exposure sciences according to a taxonomy exclusively created for exposure information. Natural Language Processing (NLP) techniques were used to extract semantic and syntactic features relevant to chemical exposure text. Using these features, we trained a supervised machine learning algorithm to automatically classify PubMed abstracts according to the exposure taxonomy. The resulting classifier demonstrates good performance in the intrinsic evaluation. We also show that the classifier improves information retrieval of chemical exposure data compared to keyword-based PubMed searches. Case studies demonstrate that the classifier can be used to assist researchers by facilitating information retrieval and classification, enabling data gap recognition and overviewing available scientific literature using chemical-specific publication profiles. Finally, we identify challenges to be addressed in future development of the system. PMID:28257498

  12. Text mining for improved exposure assessment.

    PubMed

    Larsson, Kristin; Baker, Simon; Silins, Ilona; Guo, Yufan; Stenius, Ulla; Korhonen, Anna; Berglund, Marika

    2017-01-01

    Chemical exposure assessments are based on information collected via different methods, such as biomonitoring, personal monitoring, environmental monitoring and questionnaires. The vast amount of chemical-specific exposure information available from web-based databases, such as PubMed, is undoubtedly a great asset to the scientific community. However, manual retrieval of relevant published information is an extremely time consuming task and overviewing the data is nearly impossible. Here, we present the development of an automatic classifier for chemical exposure information. First, nearly 3700 abstracts were manually annotated by an expert in exposure sciences according to a taxonomy exclusively created for exposure information. Natural Language Processing (NLP) techniques were used to extract semantic and syntactic features relevant to chemical exposure text. Using these features, we trained a supervised machine learning algorithm to automatically classify PubMed abstracts according to the exposure taxonomy. The resulting classifier demonstrates good performance in the intrinsic evaluation. We also show that the classifier improves information retrieval of chemical exposure data compared to keyword-based PubMed searches. Case studies demonstrate that the classifier can be used to assist researchers by facilitating information retrieval and classification, enabling data gap recognition and overviewing available scientific literature using chemical-specific publication profiles. Finally, we identify challenges to be addressed in future development of the system.

  13. Assessment of mechanical exposure in ergonomic epidemiology

    PubMed Central

    van der Beek, A. J.; Frings-Dresen, M. H.

    1998-01-01

    In recent years several different methods have been developed to assess mechanical exposures, which are related to musculoskeletal disorders in ergonomic epidemiology. Each of these methods is capable of measuring one or more aspects of risk factors, but has drawbacks as well. Improper application of methods might result in biased exposure estimates, which has serious consequences for risk estimates arising from epidemiological studies. The aim of this paper was to systematically evaluate the usefulness of different measurement methods in terms of accuracy and applicability. Assessment of external exposure measures by subjective judgements (from experts or self reports from workers), observational methods (on site or afterwards from video recordings), and direct measurements methods (at work or during laboratory simulations) are discussed for each of the dimensions of exposure level, duration, and frequency. It is concluded that expert judgements and self reports give only limited insight into the occurrence of tasks and activities. Further information can be obtained from observations, which can best be combined with direct measurements of exposure to posture, movement, and exerted forces to achieve exposure profiles by occupational task. Internal exposures estimated by biomechanical modelling mostly consider the low back and require information on postures of the different body segments and exerted forces, completed with movement data in the case of dynamic models. Moreover, electromyography (EMG) and measurements of intra-abdominal pressure might be used for this purpose. Both biomechanical models and EMG are useful methods to assess internal exposure, but biomechanical models should not be restricted to the level of compressive forces on the lower back. Finally, current problems and future directions in measurement strategies and methods are discussed.   PMID:9764106

  14. [Occupational exposure to nanoparticles. Assessment of workplace exposure].

    PubMed

    Bujak-Pietrek, Stella

    2010-01-01

    Nanotechnology is currently one of the most popular branch of science. It is a technology that enables designing, manufacturing and application of materials and structures of very small dimensions, and its products are applied in almost every field of life. Nanoparticles are the structures having one or more dimensions of the order of 100 nm or less. They are used in precise mechanics, electronics, optics, medicine, pharmacy, cosmetics and many other spheres. Due to their very small size, nanostructures have completely different and specific properties, unknown for the bulk of materials. Fast-growing nanotechnology provides a wide spectrum of applications, but it also brings about new and unknown danger to human health. Nanotechnology is the branch that has developed rather recently, and much information about health risk and its influence on the environment is beyond our knowledge. Nanoparticles, released in many technological processes, as well as manufactured nanoparticles can induce occupational hazards to workers. The lack of regulations and standards, compulsory in the manufacture and use ofnanoparticles is a fundamental problem faced in the evaluation of exposure. Another problem is the choice of proper measurement equipment for surveying of very small particles - their number, mass and surface area in the workpost air. In this article, the possibility and scope of exposure assessment is discussed and a brief specification of available instrumentation for counting and assessing the parameters essential for classifying the exposure to nanoparticles is presented.

  15. Assessment of inhomogeneous ELF magnetic field exposures.

    PubMed

    Leitgeb, N; Cech, R; Schröttner, J

    2008-01-01

    In daily life as well as at workplaces, exposures to inhomogeneous magnetic fields become very frequent. This makes easily applicable compliance assessment methods increasingly important. Reference levels have been defined linking basic restrictions to levels of homogeneous fields at worst-case exposure conditions. If reference levels are met, compliance with basic restrictions can be assumed. If not, further investigations could still prove compliance. Because of the lower induction efficiency, inhomogeneous magnetic fields such as from electric appliances could be allowed exceeding reference levels. To easily assess inhomogeneous magnetic fields, a quick and flexible multi-step assessment procedure is proposed. On the basis of simulations with numerical, anatomical human models reference factors were calculated elevating reference levels to link hot-spot values measured at source surfaces to basic limits and allowing accounting for different source distance, size, orientation and position. Compliance rules are proposed minimising assessment efforts.

  16. ELEMENTAL SPECIATION IN ENVIRONMENTAL EXPOSURE ASSESSMENT MATRICES

    EPA Science Inventory

    Arsenic and tin are two trace metals where exposure assessments have moved towards a speciation based approach because the toxicity is very chemical form dependent. This toxicity difference can be one of many factors which influence the formulation of certain regulations. For a...

  17. Performance of GPS-devices for environmental exposure assessment.

    PubMed

    Beekhuizen, Johan; Kromhout, Hans; Huss, Anke; Vermeulen, Roel

    2013-01-01

    Integration of individual time-location patterns with spatially resolved exposure maps enables a more accurate estimation of personal exposures to environmental pollutants than using estimates at fixed locations. Current global positioning system (GPS) devices can be used to track an individual's location. However, information on GPS-performance in environmental exposure assessment is largely missing. We therefore performed two studies. First, a commute-study, where the commute of 12 individuals was tracked twice, testing GPS-performance for five transport modes and two wearing modes. Second, an urban-tracking study, where one individual was tracked repeatedly through different areas, focused on the effect of building obstruction on GPS-performance. The median error from the true path for walking was 3.7 m, biking 2.9 m, train 4.8 m, bus 4.9 m, and car 3.3 m. Errors were larger in a high-rise commercial area (median error=7.1 m) compared with a low-rise residential area (median error=2.2 m). Thus, GPS-performance largely depends on the transport mode and urban built-up. Although ~85% of all errors were <10 m, almost 1% of the errors were >50 m. Modern GPS-devices are useful tools for environmental exposure assessment, but large GPS-errors might affect estimates of exposures with high spatial variability.

  18. Integrated Environmental Assessment Part III: ExposureAssessment

    SciTech Connect

    McKone, Thomas E.; Small, Mitchell J.

    2006-06-01

    Human exposure assessment is a key step in estimating the environmental and public health burdens that result chemical emissions in the life cycle of an industrial product or service. This column presents the third in a series of overviews of the state of the art in integrated environmental assessment - earlier columns described emissions estimation (Frey and Small, 2003) and fate and transport modeling (Ramaswami, et al., 2004). When combined, these first two assessment elements provide estimates of ambient concentrations in the environment. Here we discuss how both models and measurements are used to translate ambient concentrations into metrics of human and ecological exposure, the necessary precursors to impact assessment. Exposure assessment is the process of measuring and/or modeling the magnitude, frequency and duration of contact between a potentially harmful agent and a target population, including the size and characteristics of that population (IPCS, 2001; Zartarian, et al., 2005). Ideally the exposure assessment process should characterize the sources, routes, pathways, and uncertainties in the assessment. Route of exposure refers to the way that an agent enters the receptor during an exposure event. Humans contact pollutants through three routes--inhalation, ingestion, and dermal uptake. Inhalation occurs in both outdoor environments and indoor environments where most people spend the majority of their time. Ingestion includes both water and food, as well as soil and dust uptake due to hand-to-mouth activity. Dermal uptake occurs through contacts with consumer products; indoor and outdoor surfaces; the water supply during washing or bathing; ambient surface waters during swimming or boating; soil during activities such as work, gardening, and play; and, to a lesser extent, from the air that surrounds us. An exposure pathway is the course that a pollutant takes from an ambient environmental medium (air, soil, water, biota, etc), to an exposure medium

  19. Exposure Assessment of Chemicals from Packaging Materials

    NASA Astrophysics Data System (ADS)

    Poças, Maria De Fátima; Hogg, Timothy

    A variety of chemicals may enter our food supply, by means of intentional or unintentional addition, at different stages of the food chain. These chemicals include food additives, pesticide residues, environmental contaminants, mycotox-ins, flavoring substances, and micronutrients. Packaging systems and other food-contact materials are also a source of chemicals contaminating food products and beverages. Monitoring exposure to these chemicals has become an integral part of ensuring the safety of the food supply. Within the context of the risk analysis approach and more specifically as an integral part of risk assessment procedures, the exercise known as exposure assessment is crucial in providing data to allow sound judgments concerning risks to human health. The exercise of obtaining this data is part of the process of revealing sources of contamination and assessing the effectiveness of strategies for minimizing the risk from chemical contamination in the food supply (Lambe, 2002).

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

    EPA Science Inventory

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

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

    SciTech Connect

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

    2012-09-15

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

  2. [Algorithm for assessment of exposure to asbestos].

    PubMed

    Martines, V; Fioravanti, M; Anselmi, A; Attili, F; Battaglia, D; Cerratti, D; Ciarrocca, M; D'Amelio, R; De Lorenzo, G; Ferrante, E; Gaudioso, F; Mascia, E; Rauccio, A; Siena, S; Palitti, T; Tucci, L; Vacca, D; Vigliano, R; Zelano, V; Tomei, F; Sancini, A

    2010-01-01

    There is no universally approved method in the scientific literature to identify subjects exposed to asbestos and divide them in classes according to intensity of exposure. The aim of our work is to study and develope an algorithm based on the findings of occupational anamnestical information provided by a large group of workers. The algorithm allows to discriminate, in a probabilistic way, the risk of exposure by the attribution of a code for each worker (ELSA Code--work estimated exposure to asbestos). The ELSA code has been obtained through a synthesis of information that the international scientific literature identifies as the most predictive for the onset of asbestos-related abnormalities. Four dimensions are analyzed and described: 1) present and/or past occupation; 2) type of materials and equipment used in performing working activity; 3) environment where these activities are carried out; 4) period of time when activities are performed. Although it is possible to have informations in a subjective manner, the decisional procedure is objective and is based on the systematic evaluation of asbestos exposure. From the combination of the four identified dimensions it is possible to have 108 ELSA codes divided in three typological profiles of estimated risk of exposure. The application of the algorithm offers some advantages compared to other methods used for identifying individuals exposed to asbestos: 1) it can be computed both in case of present and past exposure to asbestos; 2) the classification of workers exposed to asbestos using ELSA code is more detailed than the one we have obtained with Job Exposure Matrix (JEM) because the ELSA Code takes in account other indicators of risk besides those considered in the JEM. This algorithm was developed for a project sponsored by the Italian Armed Forces and is also adaptable to other work conditions for in which it could be necessary to assess risk for asbestos exposure.

  3. Biomonitoring - An Exposure Science Tool for Exposure and Risk Assessment

    EPA Science Inventory

    Biomonitoring studies of environmental stressors are useful for confirming exposures, estimating dose levels, and evaluating human health risks. However, the complexities of exposure-biomarker and biomarker-response relationships have limited the use of biomarkers in exposure sc...

  4. Assessment of environmental cockroach allergen exposure.

    PubMed

    Chew, Ginger L

    2012-10-01

    In the past, cockroach allergen exposure assessment mainly focused on settled dust in homes in low-income urban cities in the United States. That choice was not wrong; without measureable levels of cockroach allergen, it is difficult to show associations with any home characteristics, much less with health outcomes (e.g., allergy, asthma). However, recent studies in other suburban areas, schools, and other countries have elucidated the importance of cockroach allergen in these environments too. In addition, characterizing the underlying factors that give rise to cockroach allergen exposure (or protect against it) can lead to more targeted public health interventions. This review discusses different approaches to sampling indoor environments, interprets recent asthma and allergy studies, compares cockroach allergen levels from past studies with those of recent studies, and describes strategies for decreasing exposures.

  5. ASSESSMENT OF DIOXIN INHALATION EXPOSURES AND ...

    EPA Pesticide Factsheets

    In the days following the September 11, 2001, terrorist attack on New York City's World Trade Center (WTC) towers, EPA, other federal agencies, and New York City and New York State public health and environmental authorities initiated numerous air monitoring activities to better understand the ongoing impact of emissions from that disaster. Using these data, EPA conducted an inhalation exposure and human health risk assessment. The overall evaluation focused on particulate matter, metals, polychlorinated biphenyls, dioxin-like compounds, asbestos, and volatile organic compounds. This paper reports on the analysis of dioxin-like compounds only.Lorber, M. 2003. Assessment of Dioxin Inhalation Exposures and Potential Health Impacts Following the Collapse of the World Trade Center Towers. Organohalogen Compounds 63 (no page numbers). journal article

  6. Toxicity assessment of unintentional exposure to multiple chemicals

    SciTech Connect

    Mumtaz, M.M. Ruiz, P.; De Rosa, C.T.

    2007-09-01

    Typically exposure to environmental chemicals is unintentional, and often the exposure is to chemical mixtures, either simultaneously or sequentially. When exposure occurs, in public health practice, it is prudent to ascertain if thresholds for harmful health effects are exceeded, whether by individual chemicals or by chemicals in combination. Three alternative approaches are available for assessing the toxicity of chemical mixtures. Each approach, however, has shortcomings. As the procedures of each approach are described in this paper, at various steps research needs are identified. Recently, reliance has increased on computational toxicology methods for predicting toxicological effects when data are limited. Advances in molecular biology, identification of biomarkers, and availability of accurate and sensitive methods allow us to more precisely define the relationships between multiple chemical exposures and health effects, both qualitatively and quantitatively. Key research needs are best fulfilled through collaborative research. It is through such collaborations that resources are most effectively leveraged to further develop and apply toxicity assessment methods that advance public health practices in vulnerable communities.

  7. Exposure factors for cleaning, automotive care, and surface protection products for exposure assessments.

    PubMed

    Park, Ji Young; Lim, Miyoung; Yang, Wonho; Lee, Kiyoung

    2017-01-01

    Accurately measuring the usage patterns of consumer products (CPs) is important to conduct realistic exposure assessments. We determined the exposure factors for 18 consumer products: household bleach, mold stain remover, all-purpose cleaner, washing machine cleaner, air conditioner cleaner, glass cleaner, drain cleaner, adhesive remover, liquid snow chain, tire shine spray, wheel cleaner, rain repellent, car wax spray, leather polish, furniture polish, anti-fog product, fabric waterproofing spray, and rust inhibitor. Field survey staff visited homes and collected product use information via face-to-face interviews. In total, 10,000 participants (5010 men and 4990 women) aged 15 years and older completed the questionnaire. Household bleach had the highest use rate of 47.4% and use rates for the other products ranged from 0.8 to 21.7%. The use rates of many CPs differed by age group and gender. Many household cleaning products were used regularly, but some products, such as air conditioner cleaner and liquid snow chain, were used in specific seasons or for specific purposes; therefore, they were used less frequently compared to cleaning products. These exposure factor data will be useful as input data for exposure and risk assessments and setting safety guidelines.

  8. 30 CFR 62.110 - Noise exposure assessment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Noise exposure assessment. 62.110 Section 62... REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.110 Noise exposure assessment. (a) The mine operator must establish a system of monitoring that evaluates each miner's noise exposure sufficiently to...

  9. 30 CFR 62.110 - Noise exposure assessment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Noise exposure assessment. 62.110 Section 62... REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.110 Noise exposure assessment. (a) The mine operator must establish a system of monitoring that evaluates each miner's noise exposure sufficiently to...

  10. 30 CFR 62.110 - Noise exposure assessment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Noise exposure assessment. 62.110 Section 62... REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.110 Noise exposure assessment. (a) The mine operator must establish a system of monitoring that evaluates each miner's noise exposure sufficiently to...

  11. 30 CFR 62.110 - Noise exposure assessment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Noise exposure assessment. 62.110 Section 62... REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.110 Noise exposure assessment. (a) The mine operator must establish a system of monitoring that evaluates each miner's noise exposure sufficiently to...

  12. 30 CFR 62.110 - Noise exposure assessment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Noise exposure assessment. 62.110 Section 62... REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.110 Noise exposure assessment. (a) The mine operator must establish a system of monitoring that evaluates each miner's noise exposure sufficiently to...

  13. 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.

  14. THE ROLE OF EXPOSURE ANALYSIS IN HUMAN HEALTH RISK ASSESSMENT

    EPA Science Inventory

    This presentation will cover the basic methodologies used for assessing human exposures to environmental pollutants, and some of the scientific challenges involved in conducting exposure and risk assessments in support of regulatory evaluations.

  15. EXPOSURE ASSESSMENT METHODS DEVELOPMENT PILOTS FOR THE NATIONAL CHILDREN'S STUDY

    EPA Science Inventory

    Accurate exposure classification tools are needed to link exposure with health effects. EPA began methods development pilot studies in 2000 to address general questions about exposures and outcome measures. Selected pilot studies are highlighted in this poster. The “Literature Re...

  16. Determining the exposure factors of personal and home care products for exposure assessment.

    PubMed

    Park, Ji Young; Lee, Kiyoung; Hwang, Yunhyung; Kim, Jin Hee

    2015-03-01

    An accurate understanding of the usage patterns of consumer products is important for realistic exposure assessment. Since such patterns differ by country, a Korean national database for exposure factors is needed. We determined the exposure factors of 10 consumer products (face cleanser, toothpaste, shampoo, hair conditioner, body wash, dish and laundry detergents, fabric deodorizer, antistatic spray, and shoe polish. Field survey staff visited homes and collected product use information by questionnaire. In total, 816 men and 2517 women aged 15 years and older from 2500 households completed the questionnaire. Field technicians also re-visited 85 households to investigate the circumstances of use and the reliability of the questionnaire data. Greater than 97% of the sampled population reported use of toothpaste and shampoo. Hair conditioner, body wash, and face cleanser were used by ~60% of the population and by specific age groups and genders. The amount of consumer products used was comparable between that reported in the questionnaire and that measured directly during house visits, and the ratios of usage amounts ranged from 0.75 to 1.69. The exposure factor data obtained from this study could be useful for regulatory agencies when setting safety guidelines for product use.

  17. A tiered approach for assessing children's exposure.

    PubMed Central

    Armstrong, T W; Hushka, L J; Tell, J G; Zaleski, R T

    2000-01-01

    Recently, intense attention has been given to children's health issues, particularly in the use of consumer products. Because of this attention, researchers have been planning and initiating studies specifically aimed at developing both toxicology data and exposure data directed to improve our understanding of industrial and consumer product chemical impacts on children's health. To ensure that this research is focused on the highest priority chemicals, we present a methodology for determining and prioritizing the higher hazard chemicals and scenarios for which children could be disproportionately or highly exposed. This tiered approach includes a screening step for initial chemical selection, a hazard assessment based on no- or lowest-observed-adverse-effect levels, and a margin of exposure (MOE) calculation. The initial chemical screen focuses on the chemical presence in specific media that are special to children, such as foods children regularly eat and drink, residential or school air, products children use, and soil and dust in and around residences. Data from the literature or from models serve as the initial exposure estimate. This methodology would allow us to focus on those chemicals to which children are most exposed that are also associated with, potentially, the highest risk. Use of the MOE calculation allows for comparison among chemicals, prioritization of chemicals for evaluation and testing, and identification of significant data gaps. PMID:10856018

  18. Environmental radiation exposure: Regulation, monitoring, and assessment

    SciTech Connect

    Chen, S.Y.; Yu, C.; Hong, K.J.

    1991-01-01

    Radioactive releases to the environment from nuclear facilities constitute a public health concern. Protecting the public from such releases can be achieved through the establishment and enforcement of regulatory standards. In the United States, numerous standards have been promulgated to regulate release control at nuclear facilities. Most recent standards are more restrictive than those in the past and require that radioactivity levels be as low as reasonably achievable (ALARA). Environmental monitoring programs and radiological dose assessment are means of ensuring compliance with regulations. Environmental monitoring programs provide empirical information on releases, such as the concentrations of released radioactivity in environmental media, while radiological dose assessment provides the analytical means of quantifying dose exposures for demonstrating compliance.

  19. Issue Paper on Metal Exposure Assessment

    EPA Pesticide Factsheets

    This paper explores the best approaches for characterizing exposure pathways and routes, estimating the most relevant exposure concentrations, linking exposure to dose, and coping with natural or background concentrations.

  20. Residential radon-222 exposure and lung cancer: exposure assessment methodology.

    PubMed

    Field, R W; Steck, D J; Lynch, C F; Brus, C P; Neuberger, J S; Kross, B C

    1996-01-01

    Although occupational epidemiological studies and animal experimentation provide strong evidence that radon-222 (222Rn) progeny exposure causes lung cancer, residential epidemiological studies have not confirmed this association. Past residential epidemiological studies have yielded contradictory findings. Exposure misclassification has seriously compromised the ability of these studies to detect whether an association exists between 222Rn exposure and lung cancer. Misclassification of 222Rn exposure has arisen primarily from: 1) detector measurement error; 2) failure to consider temporal and spatial 222Rn variations within a home; 3) missing data from previously occupied homes that currently are inaccessible; 4) failure to link 222Rn concentrations with subject mobility; and 5) measuring 222Rn gas concentration as a surrogate for 222Rn progeny exposure. This paper examines these methodological dosimetry problems and addresses how we are accounting for them in an ongoing, population-based, case-control study of 222Rn and lung cancer in Iowa.

  1. Retrospective benzene and total hydrocarbon exposure assessment for a petroleum marketing and distribution worker epidemiology study.

    PubMed

    Armstrong, T W; Pearlman, E D; Schnatter, A R; Bowes, S M; Murray, N; Nicolich, M J

    1996-04-01

    A quantitative exposure-estimating algorithm for benzene and total hydrocarbons was developed for a case control study of petroleum marketing and distribution workers. The algorithm used a multiplicative model to adjust recently measured quantitative exposure data to past scenarios for which representative exposure measurement data did not exist. This was accomplished through the development of exposure modifiers to account for differences in the workplace, the materials handled, the environmental conditions, and the tasks performed. Values for exposure modifiers were obtained empirically and through physical/chemical relationships. Dates for changes that altered exposure potential were obtained from archive records, retired employee interviews, and from current operations personnel. Exposure modifiers were used multiplicatively, adjusting available measured data to represent the relevant exposure scenario and time period. Changes in exposure modifiers translated to step changes in exposure estimates. Though limited by availability of data, a validation exercise suggested that the algorithm provided accurate exposure estimates for benzene (compared with measured data in industrial hygiene survey reports); the estimates generally differed by an average of less than 20% from the measured values. This approach is proposed to quantify exposures retrospectively where there are sufficient data to develop reliable current era estimates and where a historical accounting of key exposure modifiers can be developed, but where there are insufficient historic exposure measurements to directly assess historic exposures.

  2. NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS): OPPORTUNITIES AND LESSONS LEARNED

    EPA Science Inventory

    The National Human Exposure Assessment Survey (NHEXAS) in its fullest sense is a conceptual design, which upon implementation, will have long-term implications to exposure research and assessment. The ultimate goal is to document national distribution of human exposure to pote...

  3. Exposure Assessment Tools by Lifestages and Populations - General Population

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  4. Exposure Assessment Tools by Lifestages and Populations - Residential Consumers

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  5. Exposure Assessment Tools by Chemical Classes - Other Organics

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  6. Exposure Assessment Tools by Approaches - Indirect Estimation (Scenario Evaluation)

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases, mode

  7. Exposure Assessment Tools by Media - Soil and Dust

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  8. Exposure Assessment Tools by Media - Water and Sediment

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  9. Exposure Assessment Tools by Tiers and Types - Aggregate and Cumulative

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  10. Exposure Assessment Tools by Lifestages and Populations - Occupational Workers

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  11. Exposure Assessment Tools by Chemical Classes - Inorganics and Fibers

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  12. Exposure Assessment Tools by Lifestages and Populations - Lifestages

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  13. The Language Exposure Assessment Tool: Quantifying Language Exposure in Infants and Children

    ERIC Educational Resources Information Center

    DeAnda, Stephanie; Bosch, Laura; Poulin-Dubois, Diane; Zesiger, Pascal; Friend, Margaret

    2016-01-01

    Purpose: The aim of this study was to develop the Language Exposure Assessment Tool (LEAT) and to examine its cross-linguistic validity, reliability, and utility. The LEAT is a computerized interview-style assessment that requests parents to estimate language exposure. The LEAT yields an automatic calculation of relative language exposure and…

  14. Exposure Assessment Tools by Approaches - Exposure Reconstruction (Biomonitoring and Reverse Dosimetry)

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases,

  15. SPECIES SPECIFIC DIETARY ARSENIC EXPOSURE ASSESSMENT: THE NEED TO ESTIMATE BIOACCESSIBILITY AND ASSESSING THE IMPLIED PRESYSTEMIC METABOLISM IMPLICATIONS

    EPA Science Inventory

    The chemical form specific toxicity of arsenic dictates the need for species specific quantification in order to accurately assess the risk from an exposure. The literature has begun to produce preliminary species specific databases for certain dietary sources, but a quantitativ...

  16. Pesticide exposure, safety issues, and risk assessment indicators.

    PubMed

    Damalas, Christos A; Eleftherohorinos, Ilias G

    2011-05-01

    Pesticides are widely used in agricultural production to prevent or control pests, diseases, weeds, and other plant pathogens in an effort to reduce or eliminate yield losses and maintain high product quality. Although pesticides are developed through very strict regulation processes to function with reasonable certainty and minimal impact on human health and the environment, serious concerns have been raised about health risks resulting from occupational exposure and from residues in food and drinking water. Occupational exposure to pesticides often occurs in the case of agricultural workers in open fields and greenhouses, workers in the pesticide industry, and exterminators of house pests. Exposure of the general population to pesticides occurs primarily through eating food and drinking water contaminated with pesticide residues, whereas substantial exposure can also occur in or around the home. Regarding the adverse effects on the environment (water, soil and air contamination from leaching, runoff, and spray drift, as well as the detrimental effects on wildlife, fish, plants, and other non-target organisms), many of these effects depend on the toxicity of the pesticide, the measures taken during its application, the dosage applied, the adsorption on soil colloids, the weather conditions prevailing after application, and how long the pesticide persists in the environment. Therefore, the risk assessment of the impact of pesticides either on human health or on the environment is not an easy and particularly accurate process because of differences in the periods and levels of exposure, the types of pesticides used (regarding toxicity and persistence), and the environmental characteristics of the areas where pesticides are usually applied. Also, the number of the criteria used and the method of their implementation to assess the adverse effects of pesticides on human health could affect risk assessment and would possibly affect the characterization of the already

  17. Assessment of human exposure to gaseous pollutants

    SciTech Connect

    Baskin, L.B.; Falco, J.W. )

    1989-09-01

    A mathematical model to aid in assessment of human environmental exposure to volatile organic substances is presented. The model simulates the convective and diffusive transport of gas from the ambient environment into the human body by way of the respiratory and circulatory systems. Data required include easily obtained physical and chemical properties of substances as well as several estimated or measured physiological parameters. Transient and steady-state tissue concentrations resulting from an input atmospheric partial pressure are predicted. From these concentrations, an effective dose may be calculated, allowing for the determination of an exposure-response relationship based upon independently obtained dose-response data. The model's results compare favorably to experimental data on oxygen and halothane. Steady-state conditions are reached very rapidly. These results suggest that uptake of these substances is limited by both ventilation and perfusion. Rates are demonstrated to be essentially linear within the current neighborhoods. Conditions in which the primary processes of ventilation, diffusion, perfusion, and elimination limit uptake of gases are considered. Expressions describing the conditions necessary for a single process to limit gas uptake are derived. Accompanying equations for estimating tissue concentrations under these limiting conditions are presented.

  18. Indirect Dietary Residential Exposure Assessment Model (IDREAM) Implementation

    EPA Pesticide Factsheets

    The Indirect Dietary Residential Exposure Assessment Model (IDREAM) estimates indirect ingestion exposure to disinfectants used in residential settings on hard surfaces where there may be inadvertent transfer to edible items prepared on those surfaces.

  19. 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 ...

  20. INHALATION EXPOSURE-RESPONSE ASSESSMENTS FOR FIVE CHEMICALS

    EPA Science Inventory

    Inhalation exposure-response assessments for five chemicals (acrolein, ethylene oxide, hexachlorocyclopentadiene, hydrogen sulfide, and phosgene) for less-than-lifetime durations are being developed to inform the development of the Inhalation Exposure-Response Analysis Methodolog...

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

    EPA Science Inventory

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

  2. Exploring Global Exposure Factors Resources for Use in Consumer Exposure Assessments

    PubMed Central

    Zaleski, Rosemary T.; Egeghy, Peter P.; Hakkinen, Pertti J.

    2016-01-01

    This publication serves as a global comprehensive resource for readers seeking exposure factor data and information relevant to consumer exposure assessment. It describes the types of information that may be found in various official surveys and online and published resources. The relevant exposure factors cover a broad range, including general exposure factor data found in published compendia and databases and resources about specific exposure factors, such as human activity patterns and housing information. Also included are resources on exposure factors related to specific types of consumer products and the associated patterns of use, such as for a type of personal care product or a type of children’s toy. Further, a section on using exposure factors for designing representative exposure scenarios is included, along with a look into the future for databases and other exposure science developments relevant for consumer exposure assessment. PMID:27455300

  3. Exploring Global Exposure Factors Resources for Use in Consumer Exposure Assessments.

    PubMed

    Zaleski, Rosemary T; Egeghy, Peter P; Hakkinen, Pertti J

    2016-07-22

    This publication serves as a global comprehensive resource for readers seeking exposure factor data and information relevant to consumer exposure assessment. It describes the types of information that may be found in various official surveys and online and published resources. The relevant exposure factors cover a broad range, including general exposure factor data found in published compendia and databases and resources about specific exposure factors, such as human activity patterns and housing information. Also included are resources on exposure factors related to specific types of consumer products and the associated patterns of use, such as for a type of personal care product or a type of children's toy. Further, a section on using exposure factors for designing representative exposure scenarios is included, along with a look into the future for databases and other exposure science developments relevant for consumer exposure assessment.

  4. Human exposure assessment: a graduate level course.

    PubMed

    Lioy, P J

    1991-07-01

    The course has been offered three times. The content and the approach to each lecture has evolved after each time it was given. This is not unexpected since the field has been undergoing major transformations, and new approaches to measurement and modeling are being applied to current problems. The most recent student evaluation, 1990, indicates a difficulty rating of "just right" (70%) to "difficult" (30%). Most felt the course stimulated their interest in the topic (72%) and the examinations were learning experiences as well as a grading exercise. The major need for the discipline is an adequate text book. The GRAPE program has excellent potential as an educational took, but it needs to make more interactions and allow introduction of activities and data. The major strengths of the course are the problems provided to the students for homework. These give the student quantitative perspective on the concepts, range in values, variables, and uncertainties necessary to complete an assessment. In addition, the development of the mathematical and conceptional continuum for placing exposure assessment in the context of toxicology, environmental science, epidemiology, and clinical intervention provides a basic framework for the discipline.

  5. Human exposure assessment: a graduate level course

    SciTech Connect

    Lioy, P.J. )

    1991-07-01

    The course has been offered three times. The content and the approach to each lecture has evolved after each time it was given. This is not unexpected since the field has been undergoing major transformations, and new approaches to measurement and modeling are being applied to current problems. The most recent student evaluation, 1990, indicates a difficulty rating of just right' (70%) to difficult' (30%). Most felt the course stimulated their interest in the topic (72%) and the examinations were learning experiences as well as a grading exercise. The major need for the discipline is an adequate text book. The GRAPE program has excellent potential as an educational tool, but it needs to make more interactions and allow introduction of activities and data. The major strengths of the course are the problems provided to the students for homework. These give the student quantitative perspective on the concepts, range in values, variables, and uncertainties necessary to complete an assessment. In addition, the development of the mathematical and conceptional continuum for placing exposure assessment in the context of toxicology, environmental science, epidemiology, and clinical intervention provides a basic framework for the discipline.

  6. Exposure assessment of mobile phone base station radiation in an outdoor environment using sequential surrogate modeling.

    PubMed

    Aerts, Sam; Deschrijver, Dirk; Joseph, Wout; Verloock, Leen; Goeminne, Francis; Martens, Luc; Dhaene, Tom

    2013-05-01

    Human exposure to background radiofrequency electromagnetic fields (RF-EMF) has been increasing with the introduction of new technologies. There is a definite need for the quantification of RF-EMF exposure but a robust exposure assessment is not yet possible, mainly due to the lack of a fast and efficient measurement procedure. In this article, a new procedure is proposed for accurately mapping the exposure to base station radiation in an outdoor environment based on surrogate modeling and sequential design, an entirely new approach in the domain of dosimetry for human RF exposure. We tested our procedure in an urban area of about 0.04 km(2) for Global System for Mobile Communications (GSM) technology at 900 MHz (GSM900) using a personal exposimeter. Fifty measurement locations were sufficient to obtain a coarse street exposure map, locating regions of high and low exposure; 70 measurement locations were sufficient to characterize the electric field distribution in the area and build an accurate predictive interpolation model. Hence, accurate GSM900 downlink outdoor exposure maps (for use in, e.g., governmental risk communication and epidemiological studies) are developed by combining the proven efficiency of sequential design with the speed of exposimeter measurements and their ease of handling.

  7. Sewage sludge toxicity assessment using earthworm Eisenia fetida: can biochemical and histopathological analysis provide fast and accurate insight?

    PubMed

    Babić, S; Barišić, J; Malev, O; Klobučar, G; Popović, N Topić; Strunjak-Perović, I; Krasnići, N; Čož-Rakovac, R; Klobučar, R Sauerborn

    2016-06-01

    Sewage sludge (SS) is a complex organic by-product of wastewater treatment plants. Deposition of large amounts of SS can increase the risk of soil contamination. Therefore, there is an increasing need for fast and accurate assessment of SS toxic potential. Toxic effects of SS were tested on earthworm Eisenia fetida tissue, at the subcellular and biochemical level. Earthworms were exposed to depot sludge (DS) concentration ratio of 30 or 70 %, to undiluted and to 100 and 10 times diluted active sludge (AS). The exposure to DS lasted for 24/48 h (acute exposure), 96 h (semi-acute exposure) and 7/14/28 days (sub-chronic exposure) and 48 h for AS. Toxic effects were tested by the measurements of multixenobiotic resistance mechanism (MXR) activity and lipid peroxidation levels, as well as the observation of morphological alterations and behavioural changes. Biochemical markers confirmed the presence of MXR inhibitors in the tested AS and DS and highlighted the presence of SS-induced oxidative stress. The MXR inhibition and thiobarbituric acid reactive substance (TBARS) concentration in the whole earthworm's body were higher after the exposition to lower concentration of the DS. Furthermore, histopathological changes revealed damage to earthworm body wall tissue layers as well as to the epithelial and chloragogen cells in the typhlosole region. These changes were proportional to SS concentration in tested soils and to exposure duration. Obtained results may contribute to the understanding of SS-induced toxic effects on terrestrial invertebrates exposed through soil contact and to identify defence mechanisms of earthworms.

  8. Range-Finding Risk Assessment of Inhalation Exposure to Nanodiamonds in a Laboratory Environment

    PubMed Central

    Koivisto, Antti J.; Palomäki, Jaana E.; Viitanen, Anna-Kaisa; Siivola, Kirsi M.; Koponen, Ismo K.; Yu, Mingzhou; Kanerva, Tomi S.; Norppa, Hannu; Alenius, Harri T.; Hussein, Tareq; Savolainen, Kai M.; Hämeri, Kaarle J.

    2014-01-01

    This study considers fundamental methods in occupational risk assessment of exposure to airborne engineered nanomaterials. We discuss characterization of particle emissions, exposure assessment, hazard assessment with in vitro studies, and risk range characterization using calculated inhaled doses and dose-response translated to humans from in vitro studies. Here, the methods were utilized to assess workers’ risk range of inhalation exposure to nanodiamonds (NDs) during handling and sieving of ND powder. NDs were agglomerated to over 500 nm particles, and mean exposure levels of different work tasks varied from 0.24 to 4.96 µg·m−3 (0.08 to 0.74 cm−3). In vitro-experiments suggested that ND exposure may cause a risk for activation of inflammatory cascade. However, risk range characterization based on in vitro dose-response was not performed because accurate assessment of delivered (settled) dose on the cells was not possible. Comparison of ND exposure with common pollutants revealed that ND exposure was below 5 μg·m−3, which is one of the proposed exposure limits for diesel particulate matter, and the workers’ calculated dose of NDs during the measurement day was 74 ng which corresponded to 0.02% of the modeled daily (24 h) dose of submicrometer urban air particles. PMID:24840353

  9. Assessment and control of fetal exposure

    SciTech Connect

    Harty, R.; Swinth, K.L.; Traub, R.J.

    1991-10-01

    The assessment and control of fetal exposure to radiation in the workplace is an issue that is complicated by both biological and political/social ramifications. As a result of the dramatic increase in the number of women employed as radiation workers during the past 10 years, many facilities using radioactive materials have instituted fetal protection programs with special requirements for female radiation workers. It is necessary, however, to ensure that any fetal protection program be developed in such a way as to be nondiscriminatory. A study has been initiated whose purpose is to balance the political/social and the biological ramifications associated with occupational protection of the developing embryo/fetus. Several considerations are involved in properly balancing these factors. These considerations include appropriate methods of declaring the pregnancy, training workers, controlling the dose to the embryo/fetus, measuring and calculating the dose to the embryo/fetus, and recording the pertinent information. Alternative strategies for handling these factors while ensuring maximum protection of the embryo/fetus and the rights and responsibilities of employees and employers are discussed.

  10. AN APPROACH TO METHODS DEVELOPMENT FOR HUMAN EXPOSURE ASSESSMENT STUDIES

    EPA Science Inventory

    Human exposure assessment studies require methods that are rapid, cost-effective and have a high sample through-put. The development of analytical methods for exposure studies should be based on specific information for individual studies. Human exposure studies suggest that di...

  11. Multiple pathway asbestos exposure assessment for a Superfund community.

    PubMed

    Noonan, Curtis W; Conway, Kathrene; Landguth, Erin L; McNew, Tracy; Linker, Laura; Pfau, Jean; Black, Brad; Szeinuk, Jaime; Flores, Raja

    2015-01-01

    Libby, MT, USA, was the home to workers at a historical vermiculite mining facility and served as the processing and distribution center for this industrial product that was contaminated with amphibole asbestos. Several pathways of environmental asbestos exposure to the general population have been identified. The local clinic and health screening program collects data from participants on past occupational and environmental exposures to vermiculite and asbestos. Health studies among this population have demonstrated associations between amphibole exposure and health outcomes, but critical questions regarding the nature and level of exposure associated with specific outcomes remain unanswered. The objective of this study was to develop a comprehensive exposure assessment approach that integrates information on individuals' contact frequency with multiple exposure pathways. For 3031 participants, we describe cumulative exposure metrics for environmental exposures, occupational exposures, and residents' contact with carry-home asbestos from household workers. As expected, cumulative exposures for all three occupational categories were higher among men compared with women, and cumulative exposures for household contact and environmental pathways were higher among women. The comprehensive exposure assessment strategies will advance health studies and risk assessment approaches in this population with a complex history of both occupational and environmental asbestos exposure.

  12. Retrospective exposure assessment in a chemical research and development facility.

    PubMed

    Chen, Yu-Cheng; Ramachandran, Gurumurthy; Alexander, Bruce H; Mandel, Jeffrey H

    2012-02-01

    The objective of this exposure assessment was to reconstruct cumulative historical exposures for workers who have been exposed to multiple chemicals and chemical groups to better understand a cluster of brain cancers within a research and development lab. Chemicals of interest, including acrylates, bis-chloromethyl ether (BCME), chloromethyl methyl ether (CMME), isothiazolones and nitrosoamines, were selected on the basis of the plausibility of penetrating the blood-brain barrier and the uniqueness of the chemical's biological activity. In a complicated exposure setting such as a chemical R&D facility, multiple exposure estimation methods were needed. First, similarly exposure groups (SEGs) were created for these materials based on department group, time period of the department's existence and function associated with job titles. A probabilistic framework for assessing exposures was developed using Bayesian analysis of historical monitoring data, mathematical exposure modeling and professional judgments of current and former industrial hygienists at the facility were used to reconstruct the exposure history for acrylates, BCME and CMME for each SEG over the time period of interest. Since sufficient measurement data for isothiazolones and nitrosoamines were not available, the exposure histories for each SEG for these chemicals were estimated. This was done using objective formaldehyde levels and subjective employee interviews. The interviews assessed workplace determinants of exposure as distinct surrogates for estimating inhalation and dermal exposures. The exposure assessments by these methods were compared against each other to estimate the potential for exposure misclassification. A job exposure matrix (JEM) was constructed that contained the exposures obtained from above multiple approaches for each of these chemical groups for each SEG for each year of interest. The combination of methods used in this work is a unique and potentially helpful framework that

  13. The accurate assessment of small-angle X-ray scattering data

    SciTech Connect

    Grant, Thomas D.; Luft, Joseph R.; Carter, Lester G.; Matsui, Tsutomu; Weiss, Thomas M.; Martel, Anne; Snell, Edward H.

    2015-01-01

    A set of quantitative techniques is suggested for assessing SAXS data quality. These are applied in the form of a script, SAXStats, to a test set of 27 proteins, showing that these techniques are more sensitive than manual assessment of data quality. Small-angle X-ray scattering (SAXS) has grown in popularity in recent times with the advent of bright synchrotron X-ray sources, powerful computational resources and algorithms enabling the calculation of increasingly complex models. However, the lack of standardized data-quality metrics presents difficulties for the growing user community in accurately assessing the quality of experimental SAXS data. Here, a series of metrics to quantitatively describe SAXS data in an objective manner using statistical evaluations are defined. These metrics are applied to identify the effects of radiation damage, concentration dependence and interparticle interactions on SAXS data from a set of 27 previously described targets for which high-resolution structures have been determined via X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. The studies show that these metrics are sufficient to characterize SAXS data quality on a small sample set with statistical rigor and sensitivity similar to or better than manual analysis. The development of data-quality analysis strategies such as these initial efforts is needed to enable the accurate and unbiased assessment of SAXS data quality.

  14. An Exposure Assessment of Polybrominated Diphenyl Ethers (Pbde) (Final)

    EPA Science Inventory

    EPA announced the availability of the final report, An Exposure Assessment of Polybrominated Diphenyl Ethers. This report provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document ...

  15. Exposure assessment approaches for engineered nanomaterials.

    PubMed

    Abbott, Linda C; Maynard, Andrew D

    2010-11-01

    Products based on nanotechnology are rapidly emerging in the marketplace, sometimes with little notice to consumers of their nanotechnology pedigree. This wide variety of nanotechnology products will result (in some cases) in unintentional human exposure to purposely engineered nanoscale materials via the dermal, inhalation, ingestion, and ocular pathways. Occupational, consumer, and environmental exposure to the nanomaterials should be characterized during the entire product lifecycle-manufacture, use, and disposal. Monitoring the fate and transport of engineered nanomaterials is complicated by the lack of detection techniques and the lack of a defined set of standardized metrics to be consistently measured. New exposure metrics may be required for engineered nanomaterials, but progress is possible by building on existing tools. An exposure metric matrix could organize existing data by relating likely exposure pathways (dermal, inhalation, ocular, ingestion) with existing measurements of important characteristics of nanoscale materials (particle number, mass, size distribution, charge). Nanomaterial characteristics not commonly measured, but shown to initiate a biological response during toxicity testing, signal a need for further research, such as the pressing need to develop monitoring devices capable of measuring those aspects of engineered nanomaterials that result in biological responses in humans. Modeling the behavior of nanoparticles may require new types of exposure models that individually track particles through the environment while keeping track of the particle shape, surface area, and other surface characteristics as the nanoparticles are transformed or become reactive. Lifecycle analysis could also be used to develop conceptual models of exposure from engineered nanomaterials.

  16. Detailed behavioral assessment promotes accurate diagnosis in patients with disorders of consciousness

    PubMed Central

    Gilutz, Yael; Lazary, Avraham; Karpin, Hana; Vatine, Jean-Jacques; Misha, Tamar; Fortinsky, Hadassah; Sharon, Haggai

    2015-01-01

    Introduction: Assessing the awareness level in patients with disorders of consciousness (DOC) is made on the basis of exhibited behaviors. However, since motor signs of awareness (i.e., non-reflex motor responses) can be very subtle, differentiating the vegetative from minimally conscious states (which is in itself not clear-cut) is often challenging. Even the careful clinician relying on standardized scales may arrive at a wrong diagnosis. Aim: To report our experience in tackling this problem by using two in-house use assessment procedures developed at Reuth Rehabilitation Hospital, and demonstrate their clinical significance by reviewing two cases. Methods: (1) Reuth DOC Response Assessment (RDOC-RA) –administered in addition to the standardized tools, and emphasizes the importance of assessing a wide range of motor responses. In our experience, in some patients the only evidence for awareness may be a private specific movement that is not assessed by standard assessment tools. (2) Reuth DOC Periodic Intervention Model (RDOC-PIM) – current literature regarding assessment and diagnosis in DOC refers mostly to the acute phase of up to 1 year post injury. However, we have found major changes in responsiveness occurring 1 year or more post-injury in many patients. Therefore, we conduct periodic assessments at predetermined times points to ensure patients are not misdiagnosed or neurological changes overlooked. Results: In the first case the RDOC-RA promoted a more accurate diagnosis than that based on standardized scales alone. The second case shows how the RDOC-PIM allowed us to recognize late recovery and promoted reinstatement of treatment with good results. Conclusion: Adding a detailed periodic assessment of DOC patients to existing scales can yield critical information, promoting better diagnosis, treatment, and clinical outcomes. We discuss the implications of this observation for the future development and validation of assessment tools in DOC patients

  17. Exposure assessment in auto collision repair shops.

    PubMed

    Bejan, Anca; Brosseau, Lisa M; Parker, David L

    2011-07-01

    Workers in auto collision shops are exposed to a variety of chemical and physical hazards. Previous studies have focused on measuring levels of isocyanates, but little is known about exposures to dust, noise, and solvents. In preparation for an intervention effectiveness study in small collision repair businesses, sampling was conducted on 3 consecutive days in four representative businesses with three to seven employees. Full-shift and task-specific exposures were measured for dust and solvents (for operations other than painting and spray gun cleaning). Full-shift personal exposures and tool-specific noise levels were also evaluated. Samples of banded earplugs were distributed to employees and feedback was collected after 1 week of wear time. Dust and solvent exposures did not exceed the OSHA PELs. Noise exposure doses were below the OSHA PEL; however, 4 of the 18 measurements were in excess of the ACGIH® threshold limit value. The majority of tools generated noise levels above 85 dBA. Air guns, wrenches, cutoff wheels, and air drills generated noise levels with the 5th percentile above 90 dBA. Mean noise levels generated by hammers, grinders, and ratchets were also above 95 dBA. Three pairs of banded earplugs had the best reviews in terms of comfort of use. This study was conducted during a time when all shops reported relatively low production levels. Noise exposure results suggest that it is likely that technicians' 8-hr time-weighted average exposures may be in excess of 85 dBA during periods of higher production, but exposures to dust and solvents are unlikely to approach OSHA exposure limits. These pilot test results will be useful when developing recommendations and technical assistance materials for health and safety interventions in auto collision repair businesses.

  18. Human exposure assessment resources on the World Wide Web.

    PubMed

    Schwela, Dieter; Hakkinen, Pertti J

    2004-05-20

    Human exposure assessment is frequently noted as a weak link and bottleneck in the risk assessment process. Fortunately, the World Wide Web and Internet are providing access to numerous valuable sources of human exposure assessment-related information, along with opportunities for information exchange. Internet mailing lists are available as potential online help for exposure assessment questions, e.g. RISKANAL has several hundred members from numerous countries. Various Web sites provide opportunities for training, e.g. Web sites offering general human exposure assessment training include two from the US Environmental Protection Agency (EPA) and four from the US National Library of Medicine. Numerous other Web sites offer access to a wide range of exposure assessment information. For example, the (US) Alliance for Chemical Awareness Web site addresses direct and indirect human exposures, occupational exposures and ecological exposure assessments. The US EPA's Exposure Factors Program Web site provides a focal point for current information and data on exposure factors relevant to the United States. In addition, the International Society of Exposure Analysis Web site provides information about how this society seeks to foster and advance the science of exposure analysis. A major opportunity exists for risk assessors and others to broaden the level of exposure assessment information available via Web sites. Broadening the Web's exposure information could include human exposure factors-related information about country- or region-specific ranges in body weights, drinking water consumption, etc. along with residential factors-related information on air changeovers per hour in various types of residences. Further, country- or region-specific ranges on how various tasks are performed by various types of consumers could be collected and provided. Noteworthy are that efforts are underway in Europe to develop a multi-country collection of exposure factors and the European

  19. DREAM: a method for semi-quantitative dermal exposure assessment.

    PubMed

    Van-Wendel-de-Joode, Berna; Brouwer, Derk H; Vermeulen, Roel; Van Hemmen, Joop J; Heederik, Dick; Kromhout, Hans

    2003-01-01

    This paper describes a new method (DREAM) for structured, semi-quantitative dermal exposure assessment for chemical or biological agents that can be used in occupational hygiene or epidemiology. It is anticipated that DREAM could serve as an initial assessment of dermal exposure, amongst others, resulting in a ranking of tasks and subsequently jobs. DREAM consists of an inventory and evaluation part. Two examples of dermal exposure of workers of a car-construction company show that DREAM characterizes tasks and gives insight into exposure mechanisms, forming a basis for systematic exposure reduction. DREAM supplies estimates for exposure levels on the outside clothing layer as well as on skin, and provides insight into the distribution of dermal exposure over the body. Together with the ranking of tasks and people, this provides information for measurement strategies and helps to determine who, where and what to measure. In addition to dermal exposure assessment, the systematic description of dermal exposure pathways helps to prioritize and determine most adequate measurement strategies and methods. DREAM could be a promising approach for structured, semi-quantitative, dermal exposure assessment.

  20. Advanced REACH Tool: A Bayesian Model for Occupational Exposure Assessment

    PubMed Central

    McNally, Kevin; Warren, Nicholas; Fransman, Wouter; Entink, Rinke Klein; Schinkel, Jody; van Tongeren, Martie; Cherrie, John W.; Kromhout, Hans; Schneider, Thomas; Tielemans, Erik

    2014-01-01

    This paper describes a Bayesian model for the assessment of inhalation exposures in an occupational setting; the methodology underpins a freely available web-based application for exposure assessment, the Advanced REACH Tool (ART). The ART is a higher tier exposure tool that combines disparate sources of information within a Bayesian statistical framework. The information is obtained from expert knowledge expressed in a calibrated mechanistic model of exposure assessment, data on inter- and intra-individual variability in exposures from the literature, and context-specific exposure measurements. The ART provides central estimates and credible intervals for different percentiles of the exposure distribution, for full-shift and long-term average exposures. The ART can produce exposure estimates in the absence of measurements, but the precision of the estimates improves as more data become available. The methodology presented in this paper is able to utilize partially analogous data, a novel approach designed to make efficient use of a sparsely populated measurement database although some additional research is still required before practical implementation. The methodology is demonstrated using two worked examples: an exposure to copper pyrithione in the spraying of antifouling paints and an exposure to ethyl acetate in shoe repair. PMID:24665110

  1. Wall Paint Exposure Assessment Model (WPEM)

    EPA Pesticide Factsheets

    WPEM uses mathematical models developed from small chamber data to estimate the emissions of chemicals from oil-based (alkyd) and latex wall paint which is then combined with detailed use, workload and occupancy data to estimate user exposure.

  2. Pooled exposure assessment for matched case-control studies.

    PubMed

    Saha-Chaudhuri, Paramita; Umbach, David M; Weinberg, Clarice R

    2011-09-01

    Exposure assessment using biologic specimens is important for epidemiology but may become impracticable if assays are expensive, specimen volumes are marginally adequate, or analyte levels fall below the limit of detection. Pooled exposure assessment can provide an effective remedy for these problems in unmatched case-control studies. We extend pooled exposure strategies to handle specimens collected in a matched case-control study. We show that if a logistic model applies to individuals, then a logistic model also applies to an analysis using pooled exposures. Consequently, the individual-level odds ratio can be estimated while conserving both cost and specimen. We discuss appropriate pooling strategies for a single exposure, with adjustment for multiple, possibly continuous, covariates (confounders) and assessment of effect modification by a categorical variable. We assess the performance of the approach via simulations and conclude that pooled strategies can markedly improve efficiency for matched as well as unmatched case-control studies.

  3. Accurate assessment of Congo basin forest carbon stocks requires forest type specific assessments

    NASA Astrophysics Data System (ADS)

    Moonen, Pieter C. J.; Van Ballaert, Siege; Verbist, Bruno; Boyemba, Faustin; Muys, Bart

    2014-05-01

    carbon stocks despite poorer physical and chemical soil properties. Soil organic carbon stocks (0-100cm) did not significantly differ between forest types and were estimated at 109 ± 35 Mg C ha-1. Our results confirm recent findings of significantly lower carbon stocks in the Central Congo Basin as compared to the outer regions and of the importance of local tree height-diameter relationships for accurate carbon stock estimations.

  4. Risk assessment and management of radiofrequency radiation exposure

    NASA Astrophysics Data System (ADS)

    Dabala, Dana; Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia

    2013-11-01

    Radiofrequency radiation (RFR) industry managers, occupational physicians, security department, and other practitioners must be advised on the basic of biophysics and the health effects of RF electromagnetic fields so as to guide the management of exposure. Information on biophysics of RFR and biological/heath effects is derived from standard texts, literature and clinical experiences. Emergency treatment and ongoing care is outlined, with clinical approach integrating the circumstances of exposure and the patient's symptoms. Experimental risk assessment model in RFR chronic exposure is proposed. Planning for assessment and monitoring exposure, ongoing care, safety measures and work protection are outlining the proper management.

  5. Risk assessment and management of radiofrequency radiation exposure

    SciTech Connect

    Dabala, Dana; Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia

    2013-11-13

    Radiofrequency radiation (RFR) industry managers, occupational physicians, security department, and other practitioners must be advised on the basic of biophysics and the health effects of RF electromagnetic fields so as to guide the management of exposure. Information on biophysics of RFR and biological/heath effects is derived from standard texts, literature and clinical experiences. Emergency treatment and ongoing care is outlined, with clinical approach integrating the circumstances of exposure and the patient's symptoms. Experimental risk assessment model in RFR chronic exposure is proposed. Planning for assessment and monitoring exposure, ongoing care, safety measures and work protection are outlining the proper management.

  6. Probabilistic assessment of exposure to nail cosmetics in French consumers.

    PubMed

    Ficheux, A S; Morisset, T; Chevillotte, G; Postic, C; Roudot, A C

    2014-04-01

    The aim of this study was to assess probabilistic exposure to nail cosmetics in French consumers. The exposure assessment was performed with base coat, polish, top coat and remover. This work was done for adult and child consumers. Dermal, inhalation and oral routes were taken into account for varnishes. Exposure evaluation was performed for the inhalation route with polish remover. The main route of exposure to varnishes was the ungual route. Inhalation was the secondary route of exposure, followed by dermal and oral routes. Polish contributed most to exposure, regardless of the route of exposure. For this nail product, P50 and P95 values by ungual route were respectively equal to 1.74 mg(kg bw week)(-1) and 8.55 mg(kg bw week)(-1) for women aged 18-34 years. Exposure to polish by inhalation route was equal to 0.70 mg(kg bw week)(-1) (P50) and 5.27 mg(kg bw week)(-1) (P95). P50 and P95 values by inhalation route were respectively equal to 0.08 mg(kg bw week)(-1) and 1.14 mg(kg bw week)(-1) for consumers aged 18-34 years exposed to polish remover. This work provided current exposure data for nail cosmetics, and a basis for future toxicological studies of the uptake of substances contained in nail cosmetics in order to assess systemic exposure.

  7. The accurate assessment of small-angle X-ray scattering data

    PubMed Central

    Grant, Thomas D.; Luft, Joseph R.; Carter, Lester G.; Matsui, Tsutomu; Weiss, Thomas M.; Martel, Anne; Snell, Edward H.

    2015-01-01

    Small-angle X-ray scattering (SAXS) has grown in popularity in recent times with the advent of bright synchrotron X-ray sources, powerful computational resources and algorithms enabling the calculation of increasingly complex models. However, the lack of standardized data-quality metrics presents difficulties for the growing user community in accurately assessing the quality of experimental SAXS data. Here, a series of metrics to quantitatively describe SAXS data in an objective manner using statistical evaluations are defined. These metrics are applied to identify the effects of radiation damage, concentration dependence and interparticle interactions on SAXS data from a set of 27 previously described targets for which high-resolution structures have been determined via X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. The studies show that these metrics are sufficient to characterize SAXS data quality on a small sample set with statistical rigor and sensitivity similar to or better than manual analysis. The development of data-quality analysis strategies such as these initial efforts is needed to enable the accurate and unbiased assessment of SAXS data quality. PMID:25615859

  8. The accurate assessment of small-angle X-ray scattering data

    DOE PAGES

    Grant, Thomas D.; Luft, Joseph R.; Carter, Lester G.; ...

    2015-01-23

    Small-angle X-ray scattering (SAXS) has grown in popularity in recent times with the advent of bright synchrotron X-ray sources, powerful computational resources and algorithms enabling the calculation of increasingly complex models. However, the lack of standardized data-quality metrics presents difficulties for the growing user community in accurately assessing the quality of experimental SAXS data. Here, a series of metrics to quantitatively describe SAXS data in an objective manner using statistical evaluations are defined. These metrics are applied to identify the effects of radiation damage, concentration dependence and interparticle interactions on SAXS data from a set of 27 previously described targetsmore » for which high-resolution structures have been determined via X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Studies show that these metrics are sufficient to characterize SAXS data quality on a small sample set with statistical rigor and sensitivity similar to or better than manual analysis. The development of data-quality analysis strategies such as these initial efforts is needed to enable the accurate and unbiased assessment of SAXS data quality.« less

  9. The accurate assessment of small-angle X-ray scattering data

    SciTech Connect

    Grant, Thomas D.; Luft, Joseph R.; Carter, Lester G.; Matsui, Tsutomu; Weiss, Thomas M.; Martel, Anne; Snell, Edward H.

    2015-01-23

    Small-angle X-ray scattering (SAXS) has grown in popularity in recent times with the advent of bright synchrotron X-ray sources, powerful computational resources and algorithms enabling the calculation of increasingly complex models. However, the lack of standardized data-quality metrics presents difficulties for the growing user community in accurately assessing the quality of experimental SAXS data. Here, a series of metrics to quantitatively describe SAXS data in an objective manner using statistical evaluations are defined. These metrics are applied to identify the effects of radiation damage, concentration dependence and interparticle interactions on SAXS data from a set of 27 previously described targets for which high-resolution structures have been determined via X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Studies show that these metrics are sufficient to characterize SAXS data quality on a small sample set with statistical rigor and sensitivity similar to or better than manual analysis. The development of data-quality analysis strategies such as these initial efforts is needed to enable the accurate and unbiased assessment of SAXS data quality.

  10. Exposure Assessment Tools by Tiers and Types - Deterministic and Probabilistic Assessments

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  11. Environmental Exposure Assessment of Pesticides in Farmworker Homes

    PubMed Central

    Hoppin, Jane A.; Adgate, John L.; Eberhart, Monty; Nishioka, Marcia; Ryan, P. Barry

    2006-01-01

    Farmworkers and their families are exposed to pesticides both at work and in their homes. Environmental exposure assessment provides a means to evaluate pesticides in the environment and human contact with these chemicals through identification of sources and routes of exposure. To date, a variety of methods have been used to assess pesticide exposure among farmworker families, mostly focusing on dust and handwipe samples. While many of the methods are similar, differences in the collection, chemical analysis, and statistical analysis, can limit the comparability of results from farm-worker studies. This mini-monograph discusses the strategies used to assess pesticide exposures, presents limitations in the available data for farmworkers, and suggests research needs for future studies of pesticide exposure among farmworker families. PMID:16759997

  12. Cellular Metabolomics for Exposure and Toxicity Assessment

    EPA Science Inventory

    We have developed NMR automation and cell quench methods for cell culture-based metabolomics to study chemical exposure and toxicity. Our flow automation method is robust and free of cross contamination. The direct cell quench method is rapid and effective. Cell culture-based met...

  13. ASSESSING CHILDREN'S EXPOSURES: ISSUES, APPROACHES AND PLANS

    EPA Science Inventory

    Estimation of exposures of children to pesticides requires careful consideration of sources and concentrations of chemicals that may be present in different environmental media and in foods and beverages consumed by children, as well as the different routes and pathways of expo...

  14. Exposure Monitoring and Risk Assessment of Biphenyl in the Workplace

    PubMed Central

    Kim, Hyeon-Yeong; Shin, Sae-Mi; Ham, Miran; Lim, Cheol-Hong; Byeon, Sang-Hoon

    2015-01-01

    This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m3, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10−4 (central tendency exposure) and 0.56 × 10−4 (reasonable maximum exposure), which is below the acceptable risk value of 1.0 × 10−4. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed. PMID:25985312

  15. Wishful Thinking? Inside the Black Box of Exposure Assessment

    PubMed Central

    Money, Annemarie; Robinson, Christine; Agius, Raymond; de Vocht, Frank

    2016-01-01

    Background: Decision-making processes used by experts when undertaking occupational exposure assessment are relatively unknown, but it is often assumed that there is a common underlying method that experts employ. However, differences in training and experience of assessors make it unlikely that one general method for expert assessment would exist. Therefore, there are concerns about formalizing, validating, and comparing expert estimates within and between studies that are difficult, if not impossible, to characterize. Heuristics on the other hand (the processes involved in decision making) have been extensively studied. Heuristics are deployed by everyone as short-cuts to make the often complex process of decision-making simpler, quicker, and less burdensome. Experts’ assessments are often subject to various simplifying heuristics as a way to reach a decision in the absence of sufficient data. Therefore, investigating the underlying heuristics or decision-making processes involved may help to shed light on the ‘black box’ of exposure assessment. Methods: A mixed method study was conducted utilizing both a web-based exposure assessment exercise incorporating quantitative and semiqualitative elements of data collection, and qualitative semi-structured interviews with exposure assessors. Qualitative data were analyzed using thematic analysis. Results: Twenty-five experts completed the web-based exposure assessment exercise and 8 of these 25 were randomly selected to participate in the follow-up interview. Familiar key themes relating to the exposure assessment exercise emerged; ‘intensity’; ‘probability’; ‘agent’; ‘process’; and ‘duration’ of exposure. However, an important aspect of the detailed follow-up interviews revealed a lack of structure and order with which participants described their decision making. Participants mostly described some form of an iterative process, heavily relying on the anchoring and adjustment heuristic, which

  16. USEPA SHEDS MODEL: METHODOLOGY FOR EXPOSURE ASSESSMENT FOR WOOD PRESERVATIVES

    EPA Science Inventory

    A physically-based, Monte Carlo probabilistic model (SHEDS-Wood: Stochastic Human Exposure and Dose Simulation model for wood preservatives) has been applied to assess the exposure and dose of children to arsenic (As) and chromium (Cr) from contact with chromated copper arsenat...

  17. Population Based Exposure Assessment of Bioaccessible Arsenic in Carrots

    EPA Science Inventory

    The two predominant arsenic exposure routes are food and water. Estimating the risk from dietary exposures is complicated, owing to the chemical form dependent toxicity of arsenic and the diversity of arsenicals present in dietary matrices. Two aspects of assessing dietary expo...

  18. INDIRECT EXPOSURE ASSESSMENT AT THE U.S. EPA

    EPA Science Inventory

    In the early 1980s, exposures and subsequent health impact assessments from contaminants emitted into the air from stationary sources focused on the inhalation pathway. This 'direct' pathway of exposure was thought to be the most critical pathway, as it is for many contaminants. ...

  19. Interoceptive Assessment and Exposure in Panic Disorder: A Descriptive Study

    ERIC Educational Resources Information Center

    Schmidt, Norman B.; Trakowski, Jack

    2004-01-01

    Cognitive behavioral treatment (CBT) protocols for panic disorder (PD) typically include some form of interoceptive exposure (IE)--repeated exposure to internal sensations. Despite the widespread clinical use of IE, there is a notable absence of empirical reports about the nature of interoceptive assessments and IE. The present study was designed…

  20. EXPOSURE ASSESSMENT OF PARTICULATE MATTER FOR SUSCEPTIBLE POPULATIONS IN SEATTLE

    EPA Science Inventory

    In this article we present results from a 2-year comprehensive exposure assessment study that examined the particulate matter (PM) exposures and health effects in 108 individuals with and without chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), and as...

  1. Exploring Global Exposure Factors Resources for Use in Consumer Exposure Assessments

    EPA Science Inventory

    This publication serves as a global comprehensive resource for readers seeking exposure factor data and information relevant to consumer exposure assessment. It describes the types of information that may be found in various official surveys and online and published resources. Th...

  2. RATE Exposure Assessment Modules - EXA 408, EXA 409

    EPA Science Inventory

    EXA 408 – Interpreting Biomonitoring Data and Using Pharmacokinetic Modeling in Exposure Assessment Widespread acceptance and use of the CDC's National Health and Nutritional Examination Survey (NHANES) database, which, among other things, reports measured concentrations of...

  3. ASSESSING RESIDENTIAL EXPOSURE USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL

    EPA Science Inventory

    As part of a workshop sponsored by the Environmental Protection Agency's Office of Research and Development and Office of Pesticide Programs, the Aggregate Stochastic Human Exposure and Dose Simulation (SHEDS) Model was used to assess potential aggregate residential pesticide e...

  4. Long maximal incremental tests accurately assess aerobic fitness in class II and III obese men.

    PubMed

    Lanzi, Stefano; Codecasa, Franco; Cornacchia, Mauro; Maestrini, Sabrina; Capodaglio, Paolo; Brunani, Amelia; Fanari, Paolo; Salvadori, Alberto; Malatesta, Davide

    2015-01-01

    This study aimed to compare two different maximal incremental tests with different time durations [a maximal incremental ramp test with a short time duration (8-12 min) (STest) and a maximal incremental test with a longer time duration (20-25 min) (LTest)] to investigate whether an LTest accurately assesses aerobic fitness in class II and III obese men. Twenty obese men (BMI≥35 kg.m-2) without secondary pathologies (mean±SE; 36.7±1.9 yr; 41.8±0.7 kg*m-2) completed an STest (warm-up: 40 W; increment: 20 W*min-1) and an LTest [warm-up: 20% of the peak power output (PPO) reached during the STest; increment: 10% PPO every 5 min until 70% PPO was reached or until the respiratory exchange ratio reached 1.0, followed by 15 W.min-1 until exhaustion] on a cycle-ergometer to assess the peak oxygen uptake [Formula: see text] and peak heart rate (HRpeak) of each test. There were no significant differences in [Formula: see text] (STest: 3.1±0.1 L*min-1; LTest: 3.0±0.1 L*min-1) and HRpeak (STest: 174±4 bpm; LTest: 173±4 bpm) between the two tests. Bland-Altman plot analyses showed good agreement and Pearson product-moment and intra-class correlation coefficients showed a strong correlation between [Formula: see text] (r=0.81 for both; p≤0.001) and HRpeak (r=0.95 for both; p≤0.001) during both tests. [Formula: see text] and HRpeak assessments were not compromised by test duration in class II and III obese men. Therefore, we suggest that the LTest is a feasible test that accurately assesses aerobic fitness and may allow for the exercise intensity prescription and individualization that will lead to improved therapeutic approaches in treating obesity and severe obesity.

  5. Assessing inhalation exposure from airborne soil contaminants

    SciTech Connect

    Shinn, J.H.

    1998-04-01

    A method of estimation of inhalation exposure to airborne soil contaminants is presented. this method is derived from studies of airborne soil particles with radioactive tags. The concentration of contaminants in air (g/m{sup 3}) can be derived from the product of M, the suspended respirable dust mass concentration (g/m{sup 3}), S, the concentration of contaminant in the soil (g/g), and E{sub f}, an enhancement factor. Typical measurement methods and values of M, and E{sub f} are given along with highlights of experiences with this method.

  6. Perspectives for integrating human and environmental exposure assessments.

    PubMed

    Ciffroy, P; Péry, A R R; Roth, N

    2016-10-15

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

  7. Safety assessment of chromium by exposure from cosmetic products.

    PubMed

    Hwang, Myungsil; Yoon, Eun Kyung; Kim, Ja Young; Son, Bo Kyung; Yang, Seong Jun; Yun, Mi Ok; Choi, Sang Sook; Jang, Dong Deuk; Yoo, Tae Moo

    2009-02-01

    Low level impurities often reside in cosmetic products. The aim of the present study was to estimate the human exposure to chromium from cosmetic products purchased at a local market in South Korea, and to assess the risk on public health. Hexavalent chromium is an impurity substance that contaminates cosmetic products during manufacture. The potential for chromium to induce and elicit allergic contact dermatitis, as well as the degree of chromium exposure from cosmetic products, were assessed. Chromium exposure was estimated using the chromium concentrations found in cosmetic samples taken from the local market along with the expected user pattern data that was taken from the literature. Of the cosmetics we tested and available for purchase on the Korean market, seven had chromium contents above the detection limit of 0.1 ppm (0.1 microg/mL), ranging from 0.2 to 3.15 ppm. In risk assessment, scientifically defensible dose-response relationships must be established for the end points of concern. In the case of chromium contaminated cosmetic products, this includes conducting dose-response assessments for allergic contact dermatitis following dermal exposure. This dose-response information can then be integrated with site-specific exposure assessments to regulate consumer safety by use of these products. We found that dermal exposure to chromium concentrations ranging from 0.0002 to 0.003 microg/cm(2) does not appear to cause concern for eliciting allergic contact dermatitis.

  8. Asbestos exposure--quantitative assessment of risk

    SciTech Connect

    Hughes, J.M.; Weill, H.

    1986-01-01

    Methods for deriving quantitative estimates of asbestos-associated health risks are reviewed and their numerous assumptions and uncertainties described. These methods involve extrapolation of risks observed at past relatively high asbestos concentration levels down to usually much lower concentration levels of interest today--in some cases, orders of magnitude lower. These models are used to calculate estimates of the potential risk to workers manufacturing asbestos products and to students enrolled in schools containing asbestos products. The potential risk to workers exposed for 40 yr to 0.5 fibers per milliliter (f/ml) of mixed asbestos fiber type (a permissible workplace exposure limit under consideration by the Occupational Safety and Health Administration (OSHA) ) are estimated as 82 lifetime excess cancers per 10,000 exposed. The risk to students exposed to an average asbestos concentration of 0.001 f/ml of mixed asbestos fiber types for an average enrollment period of 6 school years is estimated as 5 lifetime excess cancers per one million exposed. If the school exposure is to chrysotile asbestos only, then the estimated risk is 1.5 lifetime excess cancers per million. Risks from other causes are presented for comparison; e.g., annual rates (per million) of 10 deaths from high school football, 14 from bicycling (10-14 yr of age), 5 to 20 for whooping cough vaccination. Decisions concerning asbestos products require participation of all parties involved and should only be made after a scientifically defensible estimate of the associated risk has been obtained. In many cases to date, such decisions have been made without adequate consideration of the level of risk or the cost-effectiveness of attempts to lower the potential risk. 73 references.

  9. CAREX Canada: an enhanced model for assessing occupational carcinogen exposure

    PubMed Central

    Peters, Cheryl E; Ge, Calvin B; Hall, Amy L; Davies, Hugh W; Demers, Paul A

    2015-01-01

    Objectives To estimate the numbers of workers exposed to known and suspected occupational carcinogens in Canada, building on the methods of CARcinogen EXposure (CAREX) projects in the European Union (EU). Methods CAREX Canada consists of estimates of the prevalence and level of exposure to occupational carcinogens. CAREX Canada includes occupational agents evaluated by the International Agency for Research on Cancer as known, probable or possible human carcinogens that were present and feasible to assess in Canadian workplaces. A Canadian Workplace Exposure Database was established to identify the potential for exposure in particular industries and occupations, and to create exposure level estimates among priority agents, where possible. CAREX EU data were reviewed for relevance to the Canadian context and the proportion of workers likely to be exposed by industry and occupation in Canada was assigned using expert assessment and agreement by a minimum of two occupational hygienists. These proportions were used to generate prevalence estimates by linkage with the Census of Population for 2006, and these estimates are available by industry, occupation, sex and province. Results CAREX Canada estimated the number of workers exposed to 44 known, probable and suspected carcinogens. Estimates of levels of exposure were further developed for 18 priority agents. Common exposures included night shift work (1.9 million exposed), solar ultraviolet radiation exposure (1.5 million exposed) and diesel engine exhaust (781 000 exposed). Conclusions A substantial proportion of Canadian workers are exposed to known and suspected carcinogens at work. PMID:24969047

  10. Risk Assessment of Baby Powder Exposure through Inhalation

    PubMed Central

    Moon, Min Chaul; Park, Jung Duck; Choi, Byung Soon; Park, So Young; Kim, Dong Won; Chung, Yong Hyun; Hisanaga, Naomi

    2011-01-01

    This study was conducted to assess the exposure risk through inhalation to baby powder for babies and adults under simulated conditions. Baby powder was applied to a baby doll and the amount of baby powder consumed per application was estimated. The airborne exposure to baby powder during application was then evaluated by sampling the airborne baby powder near the breathing zones of both the baby doll and the person applying the powder (the applicator). The average amount of baby powder consumed was 100 mg/application, and the average exposure concentration of airborne baby powder for the applicator and baby doll was 0.00527 mg/m3 (range 0.00157~0.01579 mg/m3) and 0.02207 mg/m3 (range 0.00780~ 0.04173 mg/m3), respectively. When compared with the Occupational Exposure Limit of 2 mg/m3 set by the Korean Ministry of Labor and the Threshold Limit Value (TLV) of 2 mg/m3 set by the ACGIH (American Conference of Governmental Industrial Hygienists), the exposure concentrations were much lower. Next, the exposure to asbestos-containing baby powder was estimated and the exposure risk was assessed based on the lung asbestos contents in normal humans. As a result, the estimated lung asbestos content resulting from exposure to asbestos-containing baby powder was found to be much lower than that of a normal Korean with no asbestos-related occupational history. PMID:24278563

  11. Improved Surgical Site Infection (SSI) rate through accurately assessed surgical wounds.

    PubMed

    John, Honeymol; Nimeri, Abdelrahman; Ellahham, Samer

    2015-01-01

    assignment was 36%, and the worst rates were in appendectomies (97%). Over time our incorrect wound classification decreased down to 22%, while at the same time our actual SSI wound occurrences per month and our odds ratio of SSI in the department have decreased an average of six to three per month. We followed the best practice guidelines of the ACS NSQIP. Accurate assessment of wound classification is necessary to make sure the expected SSI rates are not falsely high if wounds are under-classified. The present study shows that accurate wound classification in contaminated and dirty wounds can lead to lower odds ratio of SSI.

  12. Improved Surgical Site Infection (SSI) rate through accurately assessed surgical wounds

    PubMed Central

    John, Honeymol; Nimeri, Abdelrahman; ELLAHHAM, SAMER

    2015-01-01

    assignment was 36%, and the worst rates were in appendectomies (97%). Over time our incorrect wound classification decreased down to 22%, while at the same time our actual SSI wound occurrences per month and our odds ratio of SSI in the department have decreased an average of six to three per month. We followed the best practice guidelines of the ACS NSQIP. Accurate assessment of wound classification is necessary to make sure the expected SSI rates are not falsely high if wounds are under-classified. The present study shows that accurate wound classification in contaminated and dirty wounds can lead to lower odds ratio of SSI. PMID:26734358

  13. EPHECT II: Exposure assessment to household consumer products.

    PubMed

    Dimitroulopoulou, C; Trantallidi, M; Carrer, P; Efthimiou, G C; Bartzis, J G

    2015-12-01

    Within the framework of the EPHECT project (Emissions, exposure patterns and health effects of consumer products in the EU), irritative and respiratory health effects were assessed in relation to acute and long-term exposure to key and emerging indoor air pollutants emitted during household use of selected consumer products. In this context, inhalation exposure assessment was carried out for six selected 'target' compounds (acrolein, formaldehyde, benzene, naphthalene, d-limonene and α-pinene). This paper presents the methodology and the outcomes from the micro-environmental modelling of the 'target' pollutants following single or multiple use of selected consumer products and the subsequent exposure assessment. The results indicate that emissions from consumer products of benzene and α-pinene were not considered to contribute significantly to the EU indoor background levels, in contrast to some cases of formaldehyde and d-limonene emissions in Eastern Europe (mainly from cleaning products). The group of housekeepers in East Europe appears to experience the highest exposures to acrolein, formaldehyde and benzene, followed by the group of the retired people in North, who experiences the highest exposures to naphthalene and α-pinene. High exposure may be attributed to the scenarios developed within this project, which follow a 'most-representative worst-case scenario' strategy for exposure and health risk assessment. Despite the above limitations, this is the first comprehensive study that provides exposure estimates for 8 population groups across Europe exposed to 6 priority pollutants, as a result of the use of 15 consumer product classes in households, while accounting for regional differences in uses, use scenarios and ventilation conditions of each region.

  14. Passive smoke exposure in chronic rhinosinusitis as assessed by hair nicotine

    PubMed Central

    Wentzel, Jennifer L.; Soler, Zachary M.; White, David R.; Schlosser, Rodney J.

    2014-01-01

    Background: Prevalence of passive smoke exposure is relatively unknown in chronic rhinosinusitis (CRS). Previous studies have attempted to establish this relationship using subjective, questionnaire-based methodologies to assess smoke exposure, thus introducing the potential for error bias. The purpose of this study was to accurately determine the prevalence of passive smoke exposure in CRS and control patients using hair nicotine levels as a quantitative measure of cigarette smoke exposure. Methods: Hair samples were obtained at time of surgery from 569 patients: 404 undergoing surgery for CRS and 165 controls undergoing surgery for repair of cerebrospinal fluid leak, removal of pituitary tumors, or adenoidectomy from 2007 to 2013. Patient charts were reviewed for reported smoking status. Hair nicotine was quantified using reversed-phase high-performance liquid chromatography. Nonsmoking patients were classified as passive smoke exposed or smoke naïve according to the hair nicotine results. Statistical analysis was performed to test for differences in demographic information and smoke exposure prevalence between CRS, CRS subtypes, and controls. Results: The prevalence of passive smoke exposure in CRS as documented by hair nicotine was lower than previously reported subjective estimates. Passive smoke exposure rates were equivalent between those with CRS versus controls and significantly higher in children. Severity of passive smoke exposure was also equivalent between CRS subsets and controls. Annual passive smoke exposure prevalence did not change over time. Conclusion: There is no clear evidence of avoidance of passive smoke exposure in the CRS population compared with controls. Passive smoke exposure also remained stable over time despite recent regional implementation of smoking bans. Given the constancy of exposure, it is critical that the impact of passive smoke on CRS exacerbation, outcomes, and pathophysiology be evaluated in large-scale clinical studies

  15. SPECIATION OF ARSENIC IN EXPOSURE ASSESSMENT MATRICES

    EPA Science Inventory

    The speciaton of arsenic in water, food and urine are analytical capabilities which are an essential part in arsenic risk assessment. The cancer risk associated with arsenic has been the driving force in generating the analytical research in each of these matrices. This presentat...

  16. Risk assessment of fluoride exposure in drinking water of Tunisia.

    PubMed

    Guissouma, Wiem; Hakami, Othman; Al-Rajab, Abdul Jabbar; Tarhouni, Jamila

    2017-03-03

    The presence of fluoride in drinking water is known to reduce dental cavities among consumers, but an excessive intake of this anion might leads to dental and skeletal fluorosis. This study reports a complete survey of the fluoridated tap water taken from 100 water consumption points in Tunisia. The fluoride concentrations in tap water were between 0 and 2.4 mg L(-1). Risk assessment of Fluoride exposure was assessed depending on the age of consumers using a four-step method: hazard identification, toxicity reference values selection (TRVs), daily exposure assessment, and risk characterization. Our findings suggest that approximately 75% of the Tunisian population is at risk for dental decay, 25% have a potential dental fluorosis risk, and 20% might have a skeletal fluorosis risk according to the limits of fluoride in drinking water recommended by WHO. More investigations are recommended to assess the exposure risk of fluoride in other sources of drinking water such as bottled water.

  17. Assessing exposures in the United Kingdom's Armed Forces--a review of systems that collect data useful for exposure assessment.

    PubMed

    Capleton, A C; Short, S D; Rushton, L

    2001-10-01

    The ability to assess the exposure of individuals or groups is a critical element in any effective health surveillance system, as it provides the opportunity to identify the causes of ill health, the levels of exposure resulting in ill health and, through controlling exposures, to protect the health of Service personnel. As part of a wider programme to enhance the health surveillance capabilities of the Defence Medical Services, a project was undertaken to assess the collection and retention of data for exposure assessment in the United Kingdom's Armed Forces. The systems investigated include those for health, safety and environment policy, personnel and pay, medical records, environmental and occupational monitoring and historical records. It was found that the use of many systems for exposure assessment would be hampered by inconsistencies in the data collected, poor accessibility and linkage, and variability in the retention of the data. This paper highlights some of the problems that limit the usefulness of the record systems for exposure assessment and summarizes the principal recommendations made for enhancing the systems to better facilitate health surveillance.

  18. TIME-INTEGRATED EXPOSURE MEASURES TO IMPROVE THE PREDICTIVE POWER OF EXPOSURE CLASSIFICATION FOR EPIDEMIOLOGIC STUDIES

    EPA Science Inventory

    Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiologic...

  19. Near-field radiofrequency electromagnetic exposure assessment.

    PubMed

    Rubtsova, Nina; Perov, Sergey; Belaya, Olga; Kuster, Niels; Balzano, Quirino

    2015-09-01

    Personal wireless telecommunication devices, such as radiofrequency (RF) electromagnetic field (EMF) sources operated in vicinity of human body, have possible adverse health effects. Therefore, the correct EMF assessment is necessary in their near field. According to international near-field measurement criteria, the specific absorption rate (SAR) is used for absorbed energy distribution assessment in tissue simulating liquid phantoms. The aim of this investigation is to validate the relationship between the H-field of incident EMF and absorbed energy in phantoms. Three typical wireless telecommunication system frequencies are considered (900, 1800 and 2450 MHz). The EMF source at each frequency is an appropriate half-wave dipole antenna and the absorbing medium is a flat phantom filled with the suitable tissue simulating liquid. Two methods for SAR estimation have been used: standard procedure based on E-field measured in tissue simulating medium and a proposed evaluation by measuring the incident H-field. Compared SAR estimations were performed for various distances between sources and phantom. Also, these research data were compared with simulation results, obtained by using finite-difference time-domain method. The acquired data help to determine the source near-field space characterized by the smallest deviation between SAR estimation methods. So, this region near the RF source is suitable for correct RF energy absorption assessment using the magnetic component of the RF fields.

  20. Personal noise exposure assessment from small firearms

    NASA Astrophysics Data System (ADS)

    Kardous, Chucri A.; Murphy, William J.; Willson, Robert D.

    2003-04-01

    The National Institute for Occupational Safety and Health conducted noise exposure evaluations of law-enforcement personnel during firearms training at indoor and outdoor firing ranges. A representative cross section of weapons used by officers was measured. Shooters participated in live-fire exercise at an indoor firing range using three different weapons: a Beretta .400 caliber pistol, a Remington 12-gauge shotgun, and an M4 .223-caliber assault rifle. Indoor and outdoor measurements were obtained for the Smith and Wesson .357 pistol and Colt .450 and 9-mm pistols, the Glock .400 pistol, and the Heckler and Koch and Colt AR15 .223 rifles. Impulses were measured using a Bruel and Kjaer 4136 1/4-in. microphone and TASCAM digital audio tape recorder. Relevant impulse noise metrics were calculated. Peak levels ranged from 155 to 168 dB SPL. A-weighted equivalent levels ranged from 124 to 128 dBA. The contributions of the secondary weapon firings were approximately 1 to 9 dBA. Other parameters such as A/B durations, number and mixture of impulses, spectral content, energy, kurtosis, temporal spacing, and hearing protectors' effectiveness were examined. Comparisons of applicable damage risk criteria are presented. Further studies are needed to establish an occupational impulse noise damage risk criterion.

  1. A review of literature and computer models on exposure assessment.

    PubMed

    Butta, T E; Clarkb, M; Coulone, F; Oduyemi, K O K

    2009-12-14

    At the present time, risk analysis is an effective management tool used by environmental managers to protect the environment from inevitable anthropogenic activities. There are generic elements in environmental risk assessments, which are independent of the subject to which risk analysis is applied. Examples of these elements are: baseline study, hazard identification, hazards' concentration assessment and risk quantification. Another important example of such generic elements is exposure assessment, which is required in a risk analysis process for landfill leachate as it would in any other environmental risk issue. Furthermore, computer models are also being developed to assist risk analysis in different fields. However, in the review of current computer models and literature, particularly regarding landfills, the authors have found no evidence for the existence of a holistic exposure assessment procedure underpinned with a computational method for landfill leachate. This paper, with reference to the relevant literature and models reviewed, discusses the extent to which exposure assessment is absent in landfill risk assessment approaches. The study also indicates a number of factors and features that should be added to the exposure assessment system in order to render it more strategic, thereby enhancing the quantitative risk analysis.

  2. Assessment of potential exposure to friable insulation materials containing asbestos

    NASA Technical Reports Server (NTRS)

    Kim, W. S.; Kuivinen, D. E.

    1980-01-01

    Asbestos and the procedures for assessing potential exposure hazards are discussed. Assessment includes testing a bulk sample of the suspected material for the presence of asbestos, and monitoring the air, if necessary. Based on field inspections and laboratory analyses, the health hazard is evaluated, and abatement measures are taken if a potential hazard exists. Throughout the assessment and abatement program, all applicable regulations are administered as specified by the Environmental Protection Agency and the Occupational Safety and Health Administration.

  3. A novel method for accurate collagen and biochemical assessment of pulmonary tissue utilizing one animal

    PubMed Central

    Kliment, Corrine R; Englert, Judson M; Crum, Lauren P; Oury, Tim D

    2011-01-01

    Aim: The purpose of this study was to develop an improved method for collagen and protein assessment of fibrotic lungs while decreasing animal use. methods: 8-10 week old, male C57BL/6 mice were given a single intratracheal instillation of crocidolite asbestos or control titanium dioxide. Lungs were collected on day 14 and dried as whole lung, or homogenized in CHAPS buffer, for hydroxyproline analysis. Insoluble and salt-soluble collagen content was also determined in lung homogenates using a modified Sirius red colorimetric 96-well plate assay. results: The hydroxyproline assay showed significant increases in collagen content in the lungs of asbestos-treated mice. Identical results were present between collagen content determined on dried whole lung or whole lung homogenates. The Sirius red plate assay showed a significant increase in collagen content in lung homogenates however, this assay grossly over-estimated the total amount of collagen and underestimated changes between control and fibrotic lungs, conclusions: The proposed method provides accurate quantification of collagen content in whole lungs and additional homogenate samples for biochemical analysis from a single animal. The Sirius-red colorimetric plate assay provides a complementary method for determination of the relative changes in lung collagen but the values tend to overestimate absolute values obtained by the gold standard hydroxyproline assay and underestimate the overall fibrotic injury. PMID:21577320

  4. Algal productivity modeling: a step toward accurate assessments of full-scale algal cultivation.

    PubMed

    Béchet, Quentin; Chambonnière, Paul; Shilton, Andy; Guizard, Guillaume; Guieysse, Benoit

    2015-05-01

    A new biomass productivity model was parameterized for Chlorella vulgaris using short-term (<30 min) oxygen productivities from algal microcosms exposed to 6 light intensities (20-420 W/m(2)) and 6 temperatures (5-42 °C). The model was then validated against experimental biomass productivities recorded in bench-scale photobioreactors operated under 4 light intensities (30.6-74.3 W/m(2)) and 4 temperatures (10-30 °C), yielding an accuracy of ± 15% over 163 days of cultivation. This modeling approach addresses major challenges associated with the accurate prediction of algal productivity at full-scale. Firstly, while most prior modeling approaches have only considered the impact of light intensity on algal productivity, the model herein validated also accounts for the critical impact of temperature. Secondly, this study validates a theoretical approach to convert short-term oxygen productivities into long-term biomass productivities. Thirdly, the experimental methodology used has the practical advantage of only requiring one day of experimental work for complete model parameterization. The validation of this new modeling approach is therefore an important step for refining feasibility assessments of algae biotechnologies.

  5. The Future of Exposure Assessment: Perspectives from the ...

    EPA Pesticide Factsheets

    The British Occupational Hygiene Society, in collaboration with the Institute of Occupational Medicine, the University of Manchester, the UK Health and Safety Executive, and the University of Aberdeen hosted the 7th International Conference on the Science of Exposure Assessment (X2012) on 2 July–5 July 2012 in Edinburgh, UK. The conference ended with a special session at which invited speakers from government, industry, independent research institutes, and academia were asked to reflect on the conference and discuss what may now constitute the important highlights or drivers of future exposure assessment research. This article summarizes these discussions with respect to current and future technical and methodological developments. For the exposure science community to continue to have an impact in protecting public health, additional efforts need to be made to improve partnerships and cross-disciplinary collaborations, although it is equally important to ensure that the traditional occupational exposure themes are still covered as these issues are becoming increasingly important in the developing world. To facilitate this the ‘X’ conferences should continue to retain a holistic approach to occupational and non-occupational exposures and should actively pursue collaborations with other disciplines and professional organizations to increase the presence of consumer and environmental exposure scientists. The National Exposure Research Laboratory′s (NERL′

  6. Methods for assessing risks of dermal exposures in the workplace.

    PubMed

    McDougal, James N; Boeniger, Mark F

    2002-07-01

    The skin as a route of entry for toxic chemicals has caused increasing concern over the last decade. The assessment of systemic hazards from dermal exposures has evolved over time, often limited by the amount of experimental data available. The result is that there are many methods being used to assess safety of chemicals in the workplace. The process of assessing hazards of skin contact includes estimating the amount of substance that may end up on the skin and estimating the amount that might reach internal organs. Most times, toxicology studies by the dermal route are not available and extrapolations from other exposure routes are necessary. The hazards of particular chemicals can be expressed as "skin notations", actual exposure levels, or safe exposure times. Characterizing the risk of a specific procedure in the workplace involves determining the ratio of exposure standards to an expected exposure. The purpose of this review is to address each of the steps in the process and describe the assumptions that are part of the process. Methods are compared by describing their strengths and weaknesses. Recommendations for research in this area are also included.

  7. Stakeholder attitudes towards cumulative and aggregate exposure assessment of pesticides.

    PubMed

    Verbeke, Wim; Van Loo, Ellen J; Vanhonacker, Filiep; Delcour, Ilse; Spanoghe, Pieter; van Klaveren, Jacob D

    2015-05-01

    This study evaluates the attitudes and perspectives of different stakeholder groups (agricultural producers, pesticide manufacturers, trading companies, retailers, regulators, food safety authorities, scientists and NGOs) towards the concepts of cumulative and aggregate exposure assessment of pesticides by means of qualitative in-depth interviews (n = 15) and a quantitative stakeholder survey (n = 65). The stakeholders involved generally agreed that the use of chemical pesticides is needed, primarily for meeting the need of feeding the growing world population, while clearly acknowledging the problematic nature of human exposure to pesticide residues. Current monitoring was generally perceived to be adequate, but the timeliness and consistency of monitoring practices across countries were questioned. The concept of cumulative exposure assessment was better understood by stakeholders than the concept of aggregate exposure assessment. Identified pitfalls were data availability, data limitations, sources and ways of dealing with uncertainties, as well as information and training needs. Regulators and food safety authorities were perceived as the stakeholder groups for whom cumulative and aggregate pesticide exposure assessment methods and tools would be most useful and acceptable. Insights obtained from this exploratory study have been integrated in the development of targeted and stakeholder-tailored dissemination and training programmes that were implemented within the EU-FP7 project ACROPOLIS.

  8. Human exposure to bisphenol A by biomonitoring: Methods, results and assessment of environmental exposures

    SciTech Connect

    Dekant, Wolfgang Voelkel, Wolfgang

    2008-04-01

    Human exposure to bisphenol A is controversially discussed. This review critically assesses methods for biomonitoring of bisphenol A exposures and reported concentrations of bisphenol A in blood and urine of non-occupationally ('environmentally') exposed humans. From the many methods published to assess bisphenol A concentrations in biological media, mass spectrometry-based methods are considered most appropriate due to high sensitivity, selectivity and precision. In human blood, based on the known toxicokinetics of bisphenol A in humans, the expected very low concentrations of bisphenol A due to rapid biotransformation and the very rapid excretion result in severe limitations in the use of reported blood levels of bisphenol A for exposure assessment. Due to the rapid and complete excretion of orally administered bisphenol A, urine samples are considered as the appropriate body fluid for bisphenol A exposure assessment. In urine samples from several cohorts, bisphenol A (as glucuronide) was present in average concentrations in the range of 1-3 {mu}g/L suggesting that daily human exposure to bisphenol A is below 6 {mu}g per person (< 0.1 {mu}g/kg bw/day) for the majority of the population.

  9. Exposure to inhaled THM: comparison of continuous and event-specific exposure assessment for epidemiologic purposes.

    PubMed

    Thiriat, N; Paulus, H; Le Bot, B; Glorennec, P

    2009-10-01

    Trihalomethanes (THMs) (chloroform, bromoform, dibromochloromethane, and bromodichloromethane) are the most abundant by-products of chlorination. People are exposed to THMs through ingestion, dermal contact and inhalation. The objective of this study was to compare two methods for assessing THM inhalation: a direct method with personal monitors assessing continuous exposure and an indirect one with microenvironmental sampling and collection of time-activity data during the main event exposures: bathing, showering and swimming. This comparison was conducted to help plan a future epidemiologic study of the effects of THMs on the upper airways of children. 30 children aged from 4 to 10 years were included. They wore a 3M 3520 organic vapor monitor for 7 days. We sampled air in their bathrooms (during baths or showers) and in the indoor swimming pools they visited and recorded their time-activity patterns. We used stainless steel tubes full of Tenax to collect air samples. All analyses were performed with Gas Chromatography and Mass Spectrometry (GC-MS). Chloroform was the THM with the highest concentrations in the air of both bathrooms and indoor swimming pools. Its continuous and event exposure measurements were significantly correlated (r(s)=0.69 p<0.001). Continuous exposures were higher than event exposures, suggesting that the event exposure method does not take into account some influential microenvironments. In an epidemiologic study, this might lead to random exposure misclassification, thus underestimation of the risk, and reduced statistical power. The continuous exposure method was difficult to implement because of its poor acceptability and the fragility of the personal monitors. These two points may also reduce the statistical power of an epidemiologic study. It would be useful to test the advantages and disadvantages of a second sample in the home or of modeling the baseline concentration of THM in the home to improve the event exposure method.

  10. FEASIBILITY OF USING THE MACROACTIVITY APPROACH TO ASSESS CHILDREN'S DERMAL EXPOSURE TO PESTICIDES

    EPA Science Inventory

    Results derived from an initial assessment of critical exposure pathways for children indicate that dermal contact may result in high residential exposures to pesticides. However, data on children's exposures and activities are insufficient to support quantitative assessments ...

  11. ASSESSING EXPOSURE IN EPIDEMIOLOGIC STUDIES TO DISINFECTION BY-PRODUCTS IN DRINKING WATER: REPORT FROM AN INTERNATIONAL WORKSHOP

    EPA Science Inventory

    The inability to accurately assess exposure has been one of the major shortcomings of epidemiologic studies of disinfection by-products (DBPs) in drinking water. A number of contributing factors include: (1) limited information on the identity, occurrence, toxicity and pharmacok...

  12. Encoding negative events under stress: high subjective arousal is related to accurate emotional memory despite misinformation exposure.

    PubMed

    Hoscheidt, Siobhan M; LaBar, Kevin S; Ryan, Lee; Jacobs, W Jake; Nadel, Lynn

    2014-07-01

    Stress at encoding affects memory processes, typically enhancing, or preserving, memory for emotional information. These effects have interesting implications for eyewitness accounts, which in real-world contexts typically involve encoding an aversive event under stressful conditions followed by potential exposure to misinformation. The present study investigated memory for a negative event encoded under stress and subsequent misinformation endorsement. Healthy young adults participated in a between-groups design with three experimental sessions conducted 48 h apart. Session one consisted of a psychosocial stress induction (or control task) followed by incidental encoding of a negative slideshow. During session two, participants were asked questions about the slideshow, during which a random subgroup was exposed to misinformation. Memory for the slideshow was tested during the third session. Assessment of memory accuracy across stress and no-stress groups revealed that stress induced just prior to encoding led to significantly better memory for the slideshow overall. The classic misinformation effect was also observed - participants exposed to misinformation were significantly more likely to endorse false information during memory testing. In the stress group, however, memory accuracy and misinformation effects were moderated by arousal experienced during encoding of the negative event. Misinformed-stress group participants who reported that the negative slideshow elicited high arousal during encoding were less likely to endorse misinformation for the most aversive phase of the story. Furthermore, these individuals showed better memory for components of the aversive slideshow phase that had been directly misinformed. Results from the current study provide evidence that stress and high subjective arousal elicited by a negative event act concomitantly during encoding to enhance emotional memory such that the most aversive aspects of the event are well remembered and

  13. Is photometry an accurate and reliable method to assess boar semen concentration?

    PubMed

    Camus, A; Camugli, S; Lévêque, C; Schmitt, E; Staub, C

    2011-02-01

    Sperm concentration assessment is a key point to insure appropriate sperm number per dose in species subjected to artificial insemination (AI). The aim of the present study was to evaluate the accuracy and reliability of two commercially available photometers, AccuCell™ and AccuRead™ pre-calibrated for boar semen in comparison to UltiMate™ boar version 12.3D, NucleoCounter SP100 and Thoma hemacytometer. For each type of instrument, concentration was measured on 34 boar semen samples in quadruplicate and agreement between measurements and instruments were evaluated. Accuracy for both photometers was illustrated by mean of percentage differences to the general mean. It was -0.6% and 0.5% for Accucell™ and Accuread™ respectively, no significant differences were found between instrument and mean of measurement among all equipment. Repeatability for both photometers was 1.8% and 3.2% for AccuCell™ and AccuRead™ respectively. Low differences were observed between instruments (confidence interval 3%) except when hemacytometer was used as a reference. Even though hemacytometer is considered worldwide as the gold standard, it is the more variable instrument (confidence interval 7.1%). The conclusion is that routine photometry measures of raw semen concentration are reliable, accurate and precise using AccuRead™ or AccuCell™. There are multiple steps in semen processing that can induce sperm loss and therefore increase differences between theoretical and real sperm numbers in doses. Potential biases that depend on the workflow but not on the initial photometric measure of semen concentration are discussed.

  14. Can a Rescuer or Simulated Patient Accurately Assess Motion During Cervical Spine Stabilization Practice Sessions?

    PubMed Central

    Shrier, Ian; Boissy, Patrick; Brière, Simon; Mellette, Jay; Fecteau, Luc; Matheson, Gordon O.; Garza, Daniel; Meeuwisse, Willem H.; Segal, Eli; Boulay, John; Steele, Russell J.

    2012-01-01

    Context: Health care providers must be prepared to manage all potential spine injuries as if they are unstable. Therefore, most sport teams devote resources to training for sideline cervical spine (C-spine) emergencies. Objective: To determine (1) how accurately rescuers and simulated patients can assess motion during C-spine stabilization practice and (2) whether providing performance feedback to rescuers influences their choice of stabilization technique. Design: Crossover study. Setting: Training studio. Patients or Other Participants: Athletic trainers, athletic therapists, and physiotherapists experienced at managing suspected C-spine injuries. Intervention(s): Twelve lead rescuers (at the patient's head) performed both the head-squeeze and trap-squeeze C-spine stabilization maneuvers during 4 test scenarios: lift-and-slide and log-roll placement on a spine board and confused patient trying to sit up or rotate the head. Main Outcome Measure(s): Interrater reliability between rescuer and simulated patient quality scores for subjective evaluation of C-spine stabilization during trials (0 = best, 10 = worst), correlation between rescuers' quality scores and objective measures of motion with inertial measurement units, and frequency of change in preference for the head-squeeze versus trap-squeeze maneuver. Results: Although the weighted κ value for interrater reliability was acceptable (0.71–0.74), scores varied by 2 points or more between rescuers and simulated patients for approximately 10% to 15% of trials. Rescuers' scores correlated with objective measures, but variability was large: 38% of trials scored as 0 or 1 by the rescuer involved more than 10° of motion in at least 1 direction. Feedback did not affect the preference for the lift-and-slide placement. For the log-roll placement, 6 of 8 participants who preferred the head squeeze at baseline preferred the trap squeeze after feedback. For the confused patient, 5 of 5 participants initially preferred

  15. Exposure Assessment in the National Children’s Study: Introduction

    PubMed Central

    Needham, Larry L.; Özkaynak, Halûk; Whyatt, Robin M.; Barr, Dana B.; Wang, Richard Y.; Naeher, Luke; Akland, Gerry; Bahadori, Tina; Bradman, Asa; Fortmann, Roy; Liu, L-J. Sally; Morandi, Maria; O’Rourke, Mary Kay; Thomas, Kent; Quackenboss, James; Ryan, P. Barry; Zartarian, Valerie

    2005-01-01

    The science of exposure assessment is relatively new and evolving rapidly with the advancement of sophisticated methods for specific measurements at the picogram per gram level or lower in a variety of environmental and biologic matrices. Without this measurement capability, environmental health studies rely on questionnaires or other indirect means as the primary method to assess individual exposures. Although we use indirect methods, they are seldom used as stand-alone tools. Analyses of environmental and biologic samples have allowed us to get more precise data on exposure pathways, from sources to concentrations, to routes, to exposure, to doses. They also often allow a better estimation of the absorbed dose and its relation to potential adverse health outcomes in individuals and in populations. Here, we make note of various environmental agents and how best to assess exposure to them in the National Children’s Study—a longitudinal epidemiologic study of children’s health. Criteria for the analytical method of choice are discussed with particular emphasis on the need for long-term quality control and quality assurance measures. PMID:16079082

  16. Work routinization and implications for ergonomic exposure assessment.

    PubMed

    Gold, Judith E; Park, Jung-Soon; Punnett, Laura

    2006-01-15

    Jobs in many modern settings, including manufacturing, service, agriculture and construction, are variable in their content and timing. This prompts the need for exposure assessment methods that do not assume regular work cycles. A scheme is presented for classifying levels of routinization to inform development of an appropriate exposure assessment strategy for a given occupational setting. Five levels of routinization have been defined based on the tasks of which the job is composed: 1) a single scheduled task with a regular work cycle; 2) multiple cyclical tasks; 3) a mix of cyclical and non-cyclical tasks; 4) one non-cyclical task; 5) multiple non-cyclical tasks. This classification, based primarily on job observation, is illustrated through data from a study of automobile manufacturing workers (n = 1200), from which self-assessed exposures to physical and psychosocial stressors were also obtained. In this cohort, decision latitude was greater with higher routinization level (p < 0.0001), and the least routinized jobs showed the lowest self-reported exposure to physical ergonomic stressors. The job analysis checklist developed for non-routinized jobs is presented, and limitations of the task analysis method utilized in the study are discussed. A work sampling approach to job analysis is recommended as the most efficient way to obtain a comparable unbiased exposure estimate across all routinization levels.

  17. Skin exposure: Assessing the hazard in the workplace

    NASA Technical Reports Server (NTRS)

    Cummins, Kevin

    1994-01-01

    An outline of the Occupational Safety and Health Agency's concerns of skin exposure to hazardous chemicals is presented, followed by the corresponding slide narrations. Specifically, dermatitis and skin absorption as compared to lung absorption are addressed. Lung versus skin exposure is examined for glycol ethers and acrylamide. Examples of skin exposure include PBC's in transformers, toluene and xylene from autobody work, polynuclear aromatics (PNA's) among Coke oven workers, toluene diisocyanate (TDI), and occupational chemical exposures in an academic medical center. Permeation through gloves in the semiconductor industry is addressed as evidence for the need to assess the effectiveness of PPE (Personal Protective Equipment). This leads to the revisions of the PPE standard and the Safety and Health Program standard.

  18. The Penobscot River and environmental contaminants: Assessment of tribal exposure through sustenance lifeways

    USGS Publications Warehouse

    Marshall, Valerie; Kusnierz, Daniel; Hillger, Robert; Ferrario, Joseph; Hughes, Thomas; Diliberto, Janet; Orazio, Carl E.; Dudley, Robert W.; Byrne, Christian; Sugatt, Richard; Warren, Sarah; DeMarini, David; Elskus, Adria; Stodola, Steve; Mierzykowski, Steve; Pugh, Katie; Culbertson, Charles W.

    2015-01-01

    . The objectives of this Regional Applied Research Effort (RARE) study were to: Develop culturally sensitive methodologies for assessing the potential level of exposure tocontaminants that Penobscot Indian Nation tribal members may have from maintainingtribal sustenance practices. Conduct field surveys and laboratory analysis on targeted flora and fauna for chemicalexposure to dioxins/furans, polychlorinated biphenyls (PCBs), total mercury and methyl-mercury. Assist the Agency for Toxic Substances and Disease Registry (ATSDR) by providing thenecessary data to conduct a Public Health Assessment for the Penobscot Indian Nation. Establish protocols for assessing the level of exposure to PCBs, dioxins/furans and mercuryto PIN tribal members as a consequence of gathering tribal plants for medicinal andnutritional purposes; as well as consuming fish, wood duck, and snapping turtle as a primarysource of nutrition. Survey surface water, drinking water, and sediment from the Penobscot River and IndianIsland to assess the exposure of PIN tribal members to environmental genotoxicants thatcontinue cultural sustenance practices. This research initiative collected and analyzed sediment and biota to determine the level of contaminant exposure to Penobscot tribal members. Natural resource utilization patterns and exposure pathways were identified based on discussions with the Tribal elders. Identification of Tribal exposure factors (exposure pathways and contaminant concentrations) was essential for accurately assessing potential long-term Penobscot Indian Nation tribal members’ exposure. Based on this study, ATSDR’s Public Health Assessment (PHA) concluded that the Penobscot Indian Nation (PIN) tribal members who eat fish and snapping turtle at the ingestion levels suggested in the Wabanaki Traditional Cultural Lifeways Exposure Scenario Report (Wabanaki Exposure Scenario) may be exposed to harmful levels of mercury, dioxins/furans, dioxin-like PCBs, and ot

  19. Role of Metabolomics in Environmental Chemical Exposure and Risk Assessment

    EPA Science Inventory

    The increasing demand for the reduction, replacement, and refinement of the use of animal models in exposure assessments has stimulated the pursuit of alternative methods. This has included not only the use of the in vitro systems (e.g., cell cultures) in lieu of in vivo whole an...

  20. Exposure Assessments and Toxicology in the 21st Century

    EPA Science Inventory

    It is widely recognized that the hazard and dose response portions of chemical risk assessments are being transformed by the availability of Adverse Outcome Pathways (AOPs) and in vitro and in silico data on biological activity. This transformation is also changing the exposure a...

  1. INDIRECT EXPOSURE ASSESSMENT AT THE UNITED STATES ENRONMENTAL PROTECTION AGENCY

    EPA Science Inventory

    In the early 1980s, expousres and subsequent health impact assessments from contaminants emitted into the air from stationary sources focused on the inhalation pathway. This 'direct' pathway of exposure was thought to be the most critical pathway, as it is for many contaminants. ...

  2. An Exposure Assessment of Polybrominated Diphenyl Ethers (Pbde) (Final)

    EPA Science Inventory

    Cover of the PBDE Final Report This final report provides a comprehensive assessment of the exposure of Americans to this class of persistent ...

  3. APPLICATION OF METABOLOMICS FOR IMPROVING ECOLOGICAL EXPOSURE AND RISK ASSESSMENTS

    EPA Science Inventory

    We have developed a research program in metabolomics that involves numerous partners across EPA, other federal labs, academia, and the private sector. A primary goal is to develop metabolite-based markers that can be used by EPA in ecological exposure and risk assessments. We are...

  4. A New Model for Environmental Assessment and Exposure Reduction

    PubMed Central

    Ciaccio, Christina E.; Kennedy, Kevin; Portnoy, Jay M.

    2012-01-01

    Environmental assessment and exposure reduction are a set of diagnostic and treatment techniques that work in tandem with the traditional medical approach by reducing a patient’s exposure to adverse environmental conditions as part of medical care. Assessment involves identifying the specific exposures to which a patient is sensitive and locating the corresponding contaminants in the patient’s environment. This provides a more complete diagnostic evaluation of a patient’s problem than could be obtained merely by examining the patient alone. Exposure reduction involves reducing the identified triggers to levels that are below thresholds that are associated with increased risk of sensitization and disease morbidity. Assessment of an environment for contaminants focuses on a chain of factors that include contaminant sources such as cockroaches, rodents, dust mites and fungi that excrete contaminants into an environment, facilitative factors such as moisture, food, water and shelter that help sources to thrive, and reservoirs where contaminants can accumulate prior to subsequent transport to occupants. By using this model to guide environmental assessments and their corresponding interventions, the root cause of health problems can be addressed, leading to improved quality of life for patients and reduced need for chronic medications. PMID:22933137

  5. DERMAL EXPOSURE ASSESSMENT: A SUMMARY OF EPA APPROACHES

    EPA Science Inventory

    This final report presents a concise description and evaluation of the approaches used in the Agency for dermal exposure assessment including a discussion about harmonization and research needs in this area. The report is intended to be used by EPA program offices in their effort...

  6. EXPOSURE ASSESSMENT IN THE NATIONAL CHILDREN'S STUDY-INTRODUCTION

    EPA Science Inventory

    The science of exposure assessment is relatively new and evolving rapidly with the advancement of sophisticated methods for specific measurements at the picogram per gram level or lower in a variety of environmental and biologic matrices. Without this measurement capability, envi...

  7. PRELIMINARY EXPOSURE ASSESSMENT FINDINGS FROM THE TAMPA ASTHMATIC CHILDREN'S STUDY

    EPA Science Inventory

    The Tampa Asthmatic Children's Study (TACS) was a pilot study that focused on developing and evaluating air pollution exposure assessment methods and participant recruiting tools. The four-week study was performed in October and November, 2003. The study involved repeated daily...

  8. EXPOSURE ASSESSMENT FINDINGS FROM THE TAMPA ASTHMATIC CHILDREN'S STUDY (TACS)

    EPA Science Inventory

    The Tampa Asthmatic Children's Study (TACS) was a pilot study that focused on developing and evaluating air pollution exposure assessment methods and participant recruiting tools. The four-week study was performed in October and November, 2003. The study involved repeated daily...

  9. EPa`s program for risk assessment guidelines: Exposure issues

    SciTech Connect

    Callahan, M.A.

    1990-12-31

    Three major issues to be dealt with over the next ten years in the exposure assessment field are: consistency in terminology, the impact of computer technology on the choice of data and modeling, and conceptual issues such as the use of time-weighted averages.

  10. USE OF MACROACTIVITY APPROACH TO ASSESS DERMAL EXPOSURE

    EPA Science Inventory

    Currently, data on children's exposures and activities are very limited and insufficient to support quantitative assessments that do not rely heavily on major default assumptions as substitutes for missing information (Cohen Hubal et al. 2000a, b). Cohen Hubal et al. (2000a, b...

  11. Assessing exposure to allied ground troops in the Vietnam War: a quantitative evaluation of the Stellman Exposure Opportunity Index model.

    PubMed

    Ginevan, Michael E; Watkins, Deborah K; Ross, John H; O'Boyle, Randy A

    2009-06-01

    The Exposure Opportunity Index (EOI) is a proximity-based model developed to estimate relative exposure of ground troops in Vietnam to aerially applied herbicides. We conducted a detailed quantitative evaluation of the EOI model by using actual herbicide spray missions isolated in time and space. EOI scores were calculated for each of 36 hypothetical receptor location points associated with each spray mission for 30 herbicide missions for two time periods - day of herbicide application and day 2-3 post-application. Our analysis found an enormous range of EOI predictions with 500-1000-fold differences across missions directly under the flight path. This quantitative examination of the EOI suggests that extensive testing of the model's code is warranted. Researchers undertaking development of a proximity-based exposure model for epidemiologic studies of either Vietnam veterans or the Vietnamese population should conduct a thorough and realistic analysis of how precise and accurate the model results are likely to be and then assess whether the model results provide a useful basis for their planned epidemiologic studies.

  12. Retrospective exposure assessment to airborne asbestos among power industry workers

    PubMed Central

    2010-01-01

    Background A method of individually assessing former exposure to asbestos fibres is a precondition of risk-differentiated health surveillance. The main aims of our study were to assess former levels of airborne asbestos exposure in the power industry in Germany and to propose a basic strategy for health surveillance and the early detection of asbestos related diseases. Methods Between March 2002 and the end of 2006, we conducted a retrospective questionnaire based survey of occupational tasks and exposures with airborne asbestos fibres in a cohort of 8632 formerly asbestos exposed power industry workers. The data on exposure and occupation were entered into a specially designed computer programme, based on ambient monitoring of airborne asbestos fibre concentrations. The cumulative asbestos exposure was expressed as the product of the eight-hour time weighted average and the total duration of exposure in fibre years (fibres/cubic centimetre-years). Results Data of 7775 (90% of the total) participants working in installations for power generation, power distribution or gas supply could be evaluated. The power generation group (n = 5284) had a mean age of 56 years, were exposed for 20 years and had an average cumulative asbestos exposure of 42 fibre years. The occupational group of "metalworkers" (n = 1600) had the highest mean value of 79 fibre years. The corresponding results for the power distribution group (n = 2491) were a mean age of 45 years, a mean exposure duration of 12 years and an average cumulative asbestos exposure of only 2.5 fibre years. The gas supply workers (n = 512) had a mean age of 54 years and a mean duration of exposure of 15 years. Conclusions While the surveyed cohort as a whole was heavily exposed to asbestos dust, the power distribution group had a mean cumulative exposure of only 6% of that found in the power generation group. Based on the presented data, risk-differentiated disease surveillance focusing on metalworkers and electricians

  13. NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS): ANALYSIS OF EXPOSURE PATHWAYS AND ROUTES FOR ARSENIC AND LEAD IN EPA REGION 5

    EPA Science Inventory

    The National Human Exposure Assessment Survey (NHEXAS) Phase I field study conducted in EPA Region 5 (Great Lakes Area) provides extensive exposure data on a representative sample of approximately 250 residents of the region. Associated environmental media and biomarker (blood...

  14. Exposure assessment of MWCNTs in their life cycle

    NASA Astrophysics Data System (ADS)

    Ono-Ogasawara, M.; Takaya, M.; Yamada, M.

    2015-05-01

    Multi-walled carbon nanotubes (MWCNTs) are used as a filler in composites to obtain electrical conductivity, and improve mechanical strength and other properties. However, exposure to MWCNTs may pose health risks because of their size, shape, and insolubility. A quantitative exposure assessment method for CNTs is therefore needed. We have developed a promising carbon analysis method that considers the size distribution of elemental carbon. We conducted exposure assessment according to the lifecycle of CNTs. At the first stage, large quantity of CNTs are handled and exposure to neat CNTs is likely to occur. When large quantity of CNTs are handled, enclosure and automated process are strongly recommended. By applying appropriate measures, CNT concentration can be well controlled. Local exhaust ventilation and less-restrictive enclosures were found to work well during the second stage, which involves handling smaller CNT quantities. At measured sites, MWCNT concentrations were below an occupational exposure level proposed by Nakanishi (i.e., 0.030 mg/m3). This analysis method can also be applied to particles containing MWCNTs. At downstream stages of the lifecycle, neat MWCNTs were not observed and concentrations of embedded MWCNTs were lower than 0.015 mg/m3.

  15. Environmental exposure assessment framework for nanoparticles in solid waste

    NASA Astrophysics Data System (ADS)

    Boldrin, Alessio; Hansen, Steffen Foss; Baun, Anders; Hartmann, Nanna Isabella Bloch; Astrup, Thomas Fruergaard

    2014-06-01

    Information related to the potential environmental exposure of engineered nanomaterials (ENMs) in the solid waste management phase is extremely scarce. In this paper, we define nanowaste as separately collected or collectable waste materials which are or contain ENMs, and we present a five-step framework for the systematic assessment of ENM exposure during nanowaste management. The framework includes deriving EOL nanoproducts and evaluating the physicochemical properties of the nanostructure, matrix properties and nanowaste treatment processes as well as transformation processes and environment releases, eventually leading to a final assessment of potential ENM exposure. The proposed framework was applied to three selected nanoproducts: nanosilver polyester textile, nanoTiO2 sunscreen lotion and carbon nanotube tennis racquets. We found that the potential global environmental exposure of ENMs associated with these three products was an estimated 0.5-143 Mg/year, which can also be characterised qualitatively as medium, medium, low, respectively. Specific challenges remain and should be subject to further research: (1) analytical techniques for the characterisation of nanowaste and its transformation during waste treatment processes, (2) mechanisms for the release of ENMs, (3) the quantification of nanowaste amounts at the regional scale, (4) a definition of acceptable limit values for exposure to ENMs from nanowaste and (5) the reporting of nanowaste generation data.

  16. Advances in Inhalation Dosimetry Models and Methods for Occupational Risk Assessment and Exposure Limit Derivation

    PubMed Central

    Kuempel, Eileen D.; Sweeney, Lisa M.; Morris, John B.; Jarabek, Annie M.

    2015-01-01

    The purpose of this article is to provide an overview and practical guide to occupational health professionals concerning the derivation and use of dose estimates in risk assessment for development of occupational exposure limits (OELs) for inhaled substances. Dosimetry is the study and practice of measuring or estimating the internal dose of a substance in individuals or a population. Dosimetry thus provides an essential link to understanding the relationship between an external exposure and a biological response. Use of dosimetry principles and tools can improve the accuracy of risk assessment, and reduce the uncertainty, by providing reliable estimates of the internal dose at the target tissue. This is accomplished through specific measurement data or predictive models, when available, or the use of basic dosimetry principles for broad classes of materials. Accurate dose estimation is essential not only for dose-response assessment, but also for interspecies extrapolation and for risk characterization at given exposures. Inhalation dosimetry is the focus of this paper since it is a major route of exposure in the workplace. Practical examples of dose estimation and OEL derivation are provided for inhaled gases and particulates. PMID:26551218

  17. Ozone exposure assessment in a southern California community.

    PubMed

    Liu, L J; Delfino, R; Koutrakis, P

    1997-01-01

    An ozone exposure assessment study was conducted in a Southern California community. The Harvard ozone passive sampler was used to monitor cohorts of 22 and 18 subjects for 8 weeks during the spring and fall of 1994, respectively. Ozone exposure variables included 12-hr personal O3 measurements, stationary outdoor O3 measurements from a continuous UV photometer and from 12-hr Harvard active monitors, and time-activity information. Results showed that personal O3 exposure levels averaged one-fourth of outdoor stationary O3 levels, attributable to high percentages of time spent indoors. Personal O3 levels were not predicted well by outdoor measurements. A random-effect general linear model analysis indicated that variance in personal exposure measurements was largely accounted for by random error (59-82%), followed by inter-subject (9-18%) and between-day (9-23%) random effects. The microenvironmental model performs differently by season, with the regression model for spring cohorts exhibiting two times the R2 of the fall cohorts (R2 = 0.21 vs. 0.09). When distance from the stationary monitoring site, elevation, and traffic are taken into account in the microenvironmental models, the adjusted R2 increased almost twofold for the fall personal exposure data. The low predictive power is due primarily to the apparent spatial variation of outdoor O3 and errors in O3 measurements and in time-activity records (particularly in recording the use of air conditioning). This study highlights the magnitude of O3 exposure misclassification in epidemiological settings and proposes an approach to reduce exposure uncertainties in assessing air pollution health effects.

  18. Assessing the reproductive health of men with occupational exposures

    PubMed Central

    Schrader, Steven M; Marlow, Katherine L

    2014-01-01

    The earliest report linking environmental (occupational) exposure to adverse human male reproductive effects dates back to1775 when an English physician, Percival Pott, reported a high incidence of scrotal cancer in chimney sweeps. This observation led to safety regulations in the form of bathing requirements for these workers. The fact that male-mediated reproductive harm in humans may be a result of toxicant exposures did not become firmly established until relatively recently, when Lancranjan studied lead-exposed workers in Romania in 1975, and later in 1977, when Whorton examined the effects of dibromochloropropane (DBCP) on male workers in California. Since these discoveries, several additional human reproductive toxicants have been identified through the convergence of laboratory and observational findings. Many research gaps remain, as the pool of potential human exposures with undetermined effects on male reproduction is vast. This review provides an overview of methods used to study the effects of exposures on male reproduction and their reproductive health, with a primary emphasis on the implementation and interpretation of human studies. Emphasis will be on occupational exposures, although much of the information is also useful in assessing environmental studies, occupational exposures are usually much higher and better defined. PMID:24369130

  19. Assessing Diet as a Modifiable Risk Factor for Pesticide Exposure

    PubMed Central

    Oates, Liza; Cohen, Marc

    2011-01-01

    The effects of pesticides on the general population, largely as a result of dietary exposure, are unclear. Adopting an organic diet appears to be an obvious solution for reducing dietary pesticide exposure and this is supported by biomonitoring studies in children. However, results of research into the effects of organic diets on pesticide exposure are difficult to interpret in light of the many complexities. Therefore future studies must be carefully designed. While biomonitoring can account for differences in overall exposure it cannot necessarily attribute the source. Due diligence must be given to appropriate selection of participants, target pesticides and analytical methods to ensure that the data generated will be both scientifically rigorous and clinically useful, while minimising the costs and difficulties associated with biomonitoring studies. Study design must also consider confounders such as the unpredictable nature of chemicals and inter- and intra-individual differences in exposure and other factors that might influence susceptibility to disease. Currently the most useful measures are non-specific urinary metabolites that measure a range of organophosphate and synthetic pyrethroid insecticides. These pesticides are in common use, frequently detected in population studies and may provide a broader overview of the impact of an organic diet on pesticide exposure than pesticide-specific metabolites. More population based studies are needed for comparative purposes and improvements in analytical methods are required before many other compounds can be considered for assessment. PMID:21776202

  20. Human health risk assessment from arsenic exposures in Bangladesh.

    PubMed

    Joseph, Tijo; Dubey, Brajesh; McBean, Edward A

    2015-09-15

    High arsenic exposures, prevalent through dietary and non-dietary sources in Bangladesh, present a major health risk to the public. A quantitative human health risk assessment is described as a result of arsenic exposure through food and water intake, tea intake, accidental soil ingestion, and chewing of betel quid, while people meet their desirable dietary intake requirements throughout their lifetime. In evaluating the contribution of each intake pathway to average daily arsenic intake, the results show that food and water intake combined, makes up approximately 98% of the daily arsenic intake with the balance contributed to by intake pathways such as tea consumption, soil ingestion, and quid consumption. Under an exposure scenario where arsenic concentration in water is at the WHO guideline (0.01 mg/L), food intake is the major arsenic intake pathway ranging from 67% to 80% of the average daily arsenic intake. However, the contribution from food drops to a range of 29% to 45% for an exposure scenario where arsenic in water is at the Bangladesh standard (0.05 mg/L). The lifetime excess risk of cancer occurrence from chronic arsenic exposure, considering a population of 160 million people, based on an exposure scenario with 85 million people at the WHO guideline value and 75 million people at the Bangladesh standard, and assuming that 35 million people are associated with a heavy activity level, is estimated as 1.15 million cases.

  1. A new assessment method of outdoor tobacco smoke (OTS) exposure

    NASA Astrophysics Data System (ADS)

    Cho, Hyeri; Lee, Kiyoung

    2014-04-01

    Outdoor tobacco smoke (OTS) is concerned due to potential health effects. An assessment method of OTS exposure is needed to determine effects of OTS and validate outdoor smoking policies. The objective of this study was to develop a new method to assess OTS exposure. This study was conducted at 100 bus stops including 50 centerline bus stops and 50 roadside bus stops in Seoul, Korea. Using real-time aerosol monitor, PM2.5 was measured for 30 min at each bus stop in two seasons. ‘Peak analysis' method was developed to assess short term PM2.5 exposure by OTS. The 30-min average PM2.5 exposure at each bus stop was associated with season and bus stop location but not smoking activity. The PM2.5 peak occurrence rate by the peak analysis method was significantly associated with season, bus stop location, observed smoking occurrence, and the number of buses servicing a route. The PM2.5 peak concentration was significantly associated with season, smoking occurrence, and the number of buses servicing a route. When a smoker was standing still at the bus stop, magnitude of peak concentrations were significantly higher than when the smoker walking-through the bus stop. People were exposed to high short-term PM2.5 peak levels at bus stops, and the magnitude of peak concentrations were highest when a smoker was located close to the monitor. The magnitude of peak concentration was a good indicator helped distinguish nearby OTS exposure. Further research using ‘peak analysis' is needed to measure smoking-related exposure to PM2.5 in other outdoor locations.

  2. Occupational exposure assessment: Practices in Malaysian nuclear agency

    NASA Astrophysics Data System (ADS)

    Sarowi, S. Muhd; Ramli, S. A.; Kontol, K. Mohamad; Rahman, N. A. H. Abd.

    2016-01-01

    Malaysian Nuclear Agency (Nuclear Malaysia) is the leading agency in introducing and promoting the application of nuclear science technology in Malaysia. The agency provides major nuclear facilities purposely for research and commercialisation such as reactor, irradiation plants and radioisotope production laboratory. When dealing with ionizing radiation, there is an obligatory requirement to monitor and assess the radiation exposure to the workers. The personal dose of radiation workers were monitored monthly by assessing their Thermoluminescence Dosimeter (TLD) dose reading. This paper will discuss the current practice in managing, assessing, record keeping and reporting of the occupational exposure in Nuclear Malaysia including the Health Physic Group roles and challenges. The statistics on occupational radiation exposure of monitored workers working in different fields in Nuclear Malaysia from 2011 - 2013 will also be presented. The results show that the null hypothesis (H₀) was accepted which the means of every populations are all equal or not differ significantly. This hypothesis states that the dose exposure received by the radiation workers in Nuclear Malaysia is similar and there were no significant changes from 2011 to 2013. The radiation monitoring programme correlate with the requirement of our national law, the Atomic Energy Licensing Act 1984 (Act 304).

  3. Occupational exposure assessment: Practices in Malaysian nuclear agency

    SciTech Connect

    Sarowi, S. Muhd Ramli, S. A.; Kontol, K. Mohamad; Rahman, N. A. H. Abd.

    2016-01-22

    Malaysian Nuclear Agency (Nuclear Malaysia) is the leading agency in introducing and promoting the application of nuclear science technology in Malaysia. The agency provides major nuclear facilities purposely for research and commercialisation such as reactor, irradiation plants and radioisotope production laboratory. When dealing with ionizing radiation, there is an obligatory requirement to monitor and assess the radiation exposure to the workers. The personal dose of radiation workers were monitored monthly by assessing their Thermoluminescence Dosimeter (TLD) dose reading. This paper will discuss the current practice in managing, assessing, record keeping and reporting of the occupational exposure in Nuclear Malaysia including the Health Physic Group roles and challenges. The statistics on occupational radiation exposure of monitored workers working in different fields in Nuclear Malaysia from 2011 - 2013 will also be presented. The results show that the null hypothesis (H{sub 0}) was accepted which the means of every populations are all equal or not differ significantly. This hypothesis states that the dose exposure received by the radiation workers in Nuclear Malaysia is similar and there were no significant changes from 2011 to 2013. The radiation monitoring programme correlate with the requirement of our national law, the Atomic Energy Licensing Act 1984 (Act 304)

  4. 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

  5. Radiation exposure and risk assessment for critical female body organs

    NASA Technical Reports Server (NTRS)

    Atwell, William; Weyland, Mark D.; Hardy, Alva C.

    1991-01-01

    Space radiation exposure limits for astronauts are based on recommendations of the National Council on Radiation Protection and Measurements. These limits now include the age at exposure and sex of the astronaut. A recently-developed computerized anatomical female (CAF) model is discussed in detail. Computer-generated, cross-sectional data are presented to illustrate the completeness of the CAF model. By applying ray-tracing techniques, shield distribution functions have been computed to calculate absorbed dose and dose equivalent values for a variety of critical body organs (e.g., breasts, lungs, thyroid gland, etc.) and mission scenarios. Specific risk assessments, i.e., cancer induction and mortality, are reviewed.

  6. Simplified pregnant woman models for the fetus exposure assessment

    NASA Astrophysics Data System (ADS)

    Jala, Marjorie; Conil, Emmanuelle; Varsier, Nadège; Wiart, Joe; Hadjem, Abdelhamid; Moulines, Éric; Lévy-Leduc, Céline

    2013-05-01

    In this paper, we introduce a study that we carried out in order to validate the use of a simplified pregnant woman model for the assessment of the fetus exposure to radio frequency waves. This simplified model, based on the use of a homogeneous tissue to replace most of the inner organs of the virtual mother, would allow us to deal with many issues that are raised because of the lack of pregnant woman models for numerical dosimetry. Using specific absorption rate comparisons, we show that this model could be used to estimate the fetus exposure to plane waves.

  7. Reading Assessment Methods for Middle-School Students: An Investigation of Reading Comprehension Rate and Maze Accurate Response Rate

    ERIC Educational Resources Information Center

    Hale, Andrea D.; Henning, Jaime B.; Hawkins, Renee O.; Sheeley, Wesley; Shoemaker, Larissa; Reynolds, Jennifer R.; Moch, Christina

    2011-01-01

    This study was designed to investigate the validity of four different aloud reading comprehension assessment measures: Maze, comprehension questions, Maze accurate response rate (MARR), and reading comprehension rate (RCR). The criterion measures used in this study were the Woodcock-Johnson III Tests of Achievement (WJ-III ACH) Broad Reading…

  8. EXPOSURE ASSESSMENT TOOLS FOR CUMULATIVE RISK ASSESSMENT: MEASUREMENT OF ENDOGENOUS BIOMARKERS

    EPA Science Inventory

    Direct assessment of cumulative risks is a difficult task due to combinations of multiple chemicals, exposure pathways, and concentration profiles using suites of environmental measurements. We are investigating the use of endogenous compounds commonly present in biological medi...

  9. The U.S. Department of Agriculture Automated Multiple-Pass Method accurately assesses sodium intakes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate and practical methods to monitor sodium intake of the U.S. population are critical given current sodium reduction strategies. While the gold standard for estimating sodium intake is the 24 hour urine collection, few studies have used this biomarker to evaluate the accuracy of a dietary ins...

  10. How many standard area diagram sets are needed for accurate disease severity assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Standard area diagram sets (SADs) are widely used in plant pathology: a rater estimates disease severity by comparing an unknown sample to actual severities in the SADs and interpolates an estimate as accurately as possible (although some SADs have been developed for categorizing disease too). Most ...

  11. Pollution exposure on marine protected areas: A global assessment.

    PubMed

    Partelow, Stefan; von Wehrden, Henrik; Horn, Olga

    2015-11-15

    Marine protected areas (MPAs) face many challenges in their aim to effectively conserve marine ecosystems. In this study we analyze the extent of pollution exposure on the global fleet of MPAs. This includes indicators for current and future pollution and the implications for regionally clustered groups of MPAs with similar biophysical characteristics. To cluster MPAs into characteristic signature groups, their bathymetry, baseline biodiversity, distance from shore, mean sea surface temperature and mean sea surface salinity were used. We assess the extent at which each signature group is facing exposure from multiple pollution types. MPA groups experience similar pollution exposure on a regional level. We highlight how the challenges that MPAs face can be addressed through governance at the appropriate scale and design considerations for integrated terrestrial and marine management approaches within regional level networks. Furthermore, we present diagnostic social-ecological indicators for addressing the challenges facing unsuccessful MPAs with practical applications.

  12. Field Evaluation Of A Novel Exposure Assessment Strategy Using Respirable Coal Dust Exposures During Heat Plant Coal Receiving Operations

    DTIC Science & Technology

    2009-03-01

    officer will reap a multitude of blessing for generations of Battens. My gratitude also extends to members of my committee, Lieutenant Colonel (Dr...exposure assessment strategy (EAS) is evident. An exposure assessment strategy (EAS) is the formal plan that provides the employer (AF unit...exposure. If the assessment from the DRIs does not clearly demonstrate an acceptable or unacceptable characterization then tier-3 utilizes a planned

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

    PubMed

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

    2014-12-01

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

  14. Historical Exposures to Chemicals at the Rocky Flats Nuclear Weapons Plant: A Pilot Retrospective Exposure Assessment

    SciTech Connect

    Robertson, Janeen Denise

    1999-02-01

    In a mortality study of white males who had worked at the Rocky Flats Nuclear Weapons Plant between 1952 and 1979, an increased number of deaths from benign and unspecified intracranial neoplasms was found. A case-control study nested within this cohort investigated the hypothesis that an association existed between brain tumor death and exposure to either internally deposited plutonium or external ionizing radiation. There was no statistically significant association found between estimated radiation exposure from internally deposited plutonium and the development of brain tumors. Exposure by job or work area showed no significant difference between the cohort and the control groups. An update of the study found elevated risk estimates for (1) all lymphopoietic neoplasms, and (2) all causes of death in employees with body burdens greater than or equal to two nanocuries of plutonium. There was an excess of brain tumors for the entire cohort. Similar cohort studies conducted on worker populations from other plutonium handling facilities have not yet shown any elevated risks for brain tumors. Historically, the Rocky Flats Nuclear Weapons Plant used large quantities of chemicals in their production operations. The use of solvents, particularly carbon tetrachloride, was unique to Rocky Flats. No investigation of the possible confounding effects of chemical exposures was done in the initial studies. The objectives of the present study are to (1) investigate the history of chemical use at the Rocky Flats facility; (2) locate and analyze chemical monitoring information in order to assess employee exposure to the chemicals that were used in the highest volume; and (3) determine the feasibility of establishing a chemical exposure assessment model that could be used in future epidemiology studies.

  15. Assessment of global flood exposures - developing an appropriate approach

    NASA Astrophysics Data System (ADS)

    Millinship, Ian; Booth, Naomi

    2015-04-01

    Increasingly complex probabilistic catastrophe models have become the standard for quantitative flood risk assessments by re/insurance companies. On the one hand, probabilistic modelling of this nature is extremely useful; a large range of risk metrics can be output. However, they can be time consuming and computationally expensive to develop and run. Levels of uncertainty are persistently high despite, or perhaps because of, attempts to increase resolution and complexity. A cycle of dependency between modelling companies and re/insurers has developed whereby available models are purchased, models run, and both portfolio and model data 'improved' every year. This can lead to potential exposures in perils and territories that are not currently modelled being largely overlooked by companies, who may then face substantial and unexpected losses when large events occur in these areas. We present here an approach to assessing global flood exposures which reduces the scale and complexity of approach used and begins with the identification of hotspots where there is a significant exposure to flood risk. The method comprises four stages: i) compile consistent exposure information, ii) to apply reinsurance terms and conditions to calculate values exposed, iii) to assess the potential hazard using a global set of flood hazard maps, and iv) to identify potential risk 'hotspots' which include considerations of spatially and/or temporally clustered historical events, and local flood defences. This global exposure assessment is designed as a scoping exercise, and reveals areas or cities where the potential for accumulated loss is of significant interest to a reinsurance company, and for which there is no existing catastrophe model. These regions are then candidates for the development of deterministic scenarios, or probabilistic models. The key advantages of this approach will be discussed. These include simplicity and ability of business leaders to understand results, as well as

  16. Dioxin: exposure-response analyses and risk assessment.

    PubMed

    Steenland, Kyle; Deddens, James

    2003-07-01

    Low-levels of dioxin cause cancer in animals. In 1997 dioxin was found to be a human carcinogen by the International Agency for Research on Cancer, based largely on four studies of industrial workers exposed to high levels. Recently there has been interest in estimating human cancer risk at low level environmental exposures. Here we review quantitative exposure-response analyses and risk assessment for low environmental levels based on the largest existing cohort of workers exposed to dioxin (the U.S. NIOSH cohort). We estimate that doubling background levels of exposure, which may occur for example by eating a lot of fish which have accumulated dioxin, will increase lifetime risk of cancer death by 0.1 to 1.0%. In the US the background risk of cancer death by age 75 is 12%, so doubling background levels of dioxin exposure would increase this lifetime risk to somewhere between 12.1 and 13.0%. Our results agree broadly with results from a German cohort, which is the only other cohort for which a quantitative risk assessment has been conducted.

  17. Use-Exposure Relationships of Pesticides for Aquatic Risk Assessment

    PubMed Central

    Luo, Yuzhou; Spurlock, Frank; Deng, Xin; Gill, Sheryl; Goh, Kean

    2011-01-01

    Field-scale environmental models have been widely used in aquatic exposure assessments of pesticides. Those models usually require a large set of input parameters and separate simulations for each pesticide in evaluation. In this study, a simple use-exposure relationship is developed based on regression analysis of stochastic simulation results generated from the Pesticide Root-Zone Model (PRZM). The developed mathematical relationship estimates edge-of-field peak concentrations of pesticides from aerobic soil metabolism half-life (AERO), organic carbon-normalized soil sorption coefficient (KOC), and application rate (RATE). In a case study of California crop scenarios, the relationships explained 90–95% of the variances in the peak concentrations of dissolved pesticides as predicted by PRZM simulations for a 30-year period. KOC was identified as the governing parameter in determining the relative magnitudes of pesticide exposures in a given crop scenario. The results of model application also indicated that the effects of chemical fate processes such as partitioning and degradation on pesticide exposure were similar among crop scenarios, while the cross-scenario variations were mainly associated with the landscape characteristics, such as organic carbon contents and curve numbers. With a minimum set of input data, the use-exposure relationships proposed in this study could be used in screening procedures for potential water quality impacts from the off-site movement of pesticides. PMID:21483772

  18. Exposure assessment of microwave ovens and impact on total exposure in WLANs.

    PubMed

    Plets, David; Verloock, Leen; Van Den Bossche, Matthias; Tanghe, Emmeric; Joseph, Wout; Martens, Luc

    2016-02-01

    In situ exposure of electric fields of 11 microwave ovens is assessed in an occupational environment and in an office. Measurements as a function of distance without load and with a load of 275 ml of tap water were performed at distances of <1 m. The maximal measured field was 55.2 V m(-1) at 5 cm from the oven (without load), which is 2.5 and 1.1 times below the International Commission on Non-Ionizing Radiation Protection reference level for occupational exposure and general public exposure, respectively. For exposure at distances of >1 m, a model of the electric field in a realistic environment is proposed. In an office scenario, switching on a microwave oven increases the median field strength from 91 to 145 mV m(-1) (+91 %) in a traditional Wireless Local Area Network (WLAN) deployment and from 44 to 92 mV m(-1) (+109 %) in an exposure-optimised WLAN deployment.

  19. Risk Assessment of Radiation Exposure using Molecular Biodosimetry

    NASA Technical Reports Server (NTRS)

    Elliott, Todd F.; George, K.; Hammond, D. K.; Cucinotta, F. A.

    2007-01-01

    Current cytogenetic biodosimetry methods would be difficult to adapt to spaceflight operations, because they require toxic chemicals and a substantial amount of time to perform. In addition, current biodosimetry techniques are limited to whole body doses over about 10cGy. Development of new techniques that assess radiation exposure response at the molecular level could overcome these limitations and have important implications in the advancement of biodosimetry. Recent technical advances include expression profiling at the transcript and protein level to assess multiple biomarkers of exposure, which may lead to the development of a radiation biomarker panel revealing possible fingerprints of individual radiation sensitivity. So far, many biomarkers of interest have been examined in their response to ionizing radiation, such as cytokines and members of the DNA repair pathway. New technology, such as the Luminex system can analyze many biomarkers simultaneously in one sample.

  20. Is the hair nicotine level a more accurate biomarker of environmental tobacco smoke exposure than urine cotinine?

    PubMed Central

    Al-Delaimy, W; Crane, J; Woodward, A

    2002-01-01

    Study objective: The aim of this study was to compare the two biomarkers of exposure to environmental tobacco smoke (ETS); urine cotinine and hair nicotine, using questionnaires as the standard. Design: A cross sectional study of children consecutively admitted to hospital for lower respiratory illnesses during the period of the study. Settings: Three regional hospitals in the larger Wellington area, New Zealand. Participants: Children aged 3–27 months and admitted to the above hospitals during August 1997 to October 1998. A total of 322 children provided 297 hair samples and 158 urine samples. Main results: Hair nicotine levels were better able to discriminate the groups of children according to their household's smoking habits at home (no smokers, smoke only outside the home, smoke inside the house) than urine cotinine (Kruskall-Wallis; χ2=142.14, and χ2=49.5, respectively (p<0.0001)). Furthermore, hair nicotine levels were more strongly correlated with number of smokers in the house, and the number of cigarettes smoked by parents and other members of the child's households. Hair nicotine was better related to the questionnaire variables of smoking in a multivariate regression model (r2=0.55) than urine cotinine (r2=0.31). Conclusions: In this group of young children, hair nicotine was a more precise biomarker of exposure to ETS than urine cotinine levels, using questionnaire reports as the reference. Both biomarkers indicate that smoking outside the house limits ETS exposure of children but does not eliminate it. PMID:11801622

  1. Dermal Exposure Assessment to Pesticides in Farming Systems in Developing Countries: Comparison of Models

    PubMed Central

    Lesmes Fabian, Camilo; Binder, Claudia R.

    2015-01-01

    In the field of occupational hygiene, researchers have been working on developing appropriate methods to estimate human exposure to pesticides in order to assess the risk and therefore to take the due decisions to improve the pesticide management process and reduce the health risks. This paper evaluates dermal exposure models to find the most appropriate. Eight models (i.e., COSHH, DERM, DREAM, EASE, PHED, RISKOFDERM, STOFFENMANAGER and PFAM) were evaluated according to a multi-criteria analysis and from these results five models (i.e., DERM, DREAM, PHED, RISKOFDERM and PFAM) were selected for the assessment of dermal exposure in the case study of the potato farming system in the Andean highlands of Vereda La Hoya, Colombia. The results show that the models provide different dermal exposure estimations which are not comparable. However, because of the simplicity of the algorithm and the specificity of the determinants, the DERM, DREAM and PFAM models were found to be the most appropriate although their estimations might be more accurate if specific determinants are included for the case studies in developing countries. PMID:25938911

  2. Dermal exposure assessment to pesticides in farming systems in developing countries: comparison of models.

    PubMed

    Lesmes-Fabian, Camilo; Fabian, Camilo Lesmes; Binder, Claudia R

    2015-04-29

    In the field of occupational hygiene, researchers have been working on developing appropriate methods to estimate human exposure to pesticides in order to assess the risk and therefore to take the due decisions to improve the pesticide management process and reduce the health risks. This paper evaluates dermal exposure models to find the most appropriate. Eight models (i.e., COSHH, DERM, DREAM, EASE, PHED, RISKOFDERM, STOFFENMANAGER and PFAM) were evaluated according to a multi-criteria analysis and from these results five models (i.e., DERM, DREAM, PHED, RISKOFDERM and PFAM) were selected for the assessment of dermal exposure in the case study of the potato farming system in the Andean highlands of Vereda La Hoya, Colombia. The results show that the models provide different dermal exposure estimations which are not comparable. However, because of the simplicity of the algorithm and the specificity of the determinants, the DERM, DREAM and PFAM models were found to be the most appropriate although their estimations might be more accurate if specific determinants are included for the case studies in developing countries.

  3. The effect of manipulated and accurate assessment feedback on the self-efficacy of dance students.

    PubMed

    García-Dantas, Ana; Quested, Eleanor

    2015-03-01

    Research undertaken with athletes has shown that lower-evaluated feedback is related to low self-efficacy levels. However, the relationship between teacher feedback and self-efficacy has not been studied in the dance setting. In sports or dance contexts, very few studies have manipulated feedback content to examine its impact on performers' self-efficacy in relation to the execution of a specific movement. Therefore, the aim of this investigation was to explore the effect of manipulated upper, lower, and accurate grade feedback on changes in dancers' self-efficacy levels for the execution of the "Zapateado" (a flamenco foot movement). Sixty-one students (56 female, 5 male, ages 13 to 22 ± 3.25 years) from a Spanish dance conservatory participated in this experimental study. They were randomly divided into four feedback groups: 1. upper-evaluated, 2. objective and informational, 3. lower-evaluated, and 4. no feedback-control. Participants performed three trials during a 1-hour session and completed questionnaires tapping self-efficacy pre-feedback and post-feedback. After each trial, teachers (who were confederates in the study) were first asked to rate their perception of each dancer's competence level at performing the movement according to conventional criteria (scores from 0 to 10). The results were then manipulated, and students accurate, lower-evaluated, or upper-evaluated scores were given. Those in the accurate feedback group reported positive change in self-efficacy, whereas those in the lower-evaluated group showed no significant change in self-efficacy during the course of the trial. Findings call into question the common perception among teachers that it can be motivating to provide students with inaccurate feedback that indicates that the students' performance level is much better or much worse than they actually perceive it to be. Self-efficacy appears most likely to increase in students when feedback is accurate.

  4. SPECT-OPT multimodal imaging enables accurate evaluation of radiotracers for β-cell mass assessments

    PubMed Central

    Eter, Wael A.; Parween, Saba; Joosten, Lieke; Frielink, Cathelijne; Eriksson, Maria; Brom, Maarten; Ahlgren, Ulf; Gotthardt, Martin

    2016-01-01

    Single Photon Emission Computed Tomography (SPECT) has become a promising experimental approach to monitor changes in β-cell mass (BCM) during diabetes progression. SPECT imaging of pancreatic islets is most commonly cross-validated by stereological analysis of histological pancreatic sections after insulin staining. Typically, stereological methods do not accurately determine the total β-cell volume, which is inconvenient when correlating total pancreatic tracer uptake with BCM. Alternative methods are therefore warranted to cross-validate β-cell imaging using radiotracers. In this study, we introduce multimodal SPECT - optical projection tomography (OPT) imaging as an accurate approach to cross-validate radionuclide-based imaging of β-cells. Uptake of a promising radiotracer for β-cell imaging by SPECT, 111In-exendin-3, was measured by ex vivo-SPECT and cross evaluated by 3D quantitative OPT imaging as well as with histology within healthy and alloxan-treated Brown Norway rat pancreata. SPECT signal was in excellent linear correlation with OPT data as compared to histology. While histological determination of islet spatial distribution was challenging, SPECT and OPT revealed similar distribution patterns of 111In-exendin-3 and insulin positive β-cell volumes between different pancreatic lobes, both visually and quantitatively. We propose ex vivo SPECT-OPT multimodal imaging as a highly accurate strategy for validating the performance of β-cell radiotracers. PMID:27080529

  5. SPECT-OPT multimodal imaging enables accurate evaluation of radiotracers for β-cell mass assessments.

    PubMed

    Eter, Wael A; Parween, Saba; Joosten, Lieke; Frielink, Cathelijne; Eriksson, Maria; Brom, Maarten; Ahlgren, Ulf; Gotthardt, Martin

    2016-04-15

    Single Photon Emission Computed Tomography (SPECT) has become a promising experimental approach to monitor changes in β-cell mass (BCM) during diabetes progression. SPECT imaging of pancreatic islets is most commonly cross-validated by stereological analysis of histological pancreatic sections after insulin staining. Typically, stereological methods do not accurately determine the total β-cell volume, which is inconvenient when correlating total pancreatic tracer uptake with BCM. Alternative methods are therefore warranted to cross-validate β-cell imaging using radiotracers. In this study, we introduce multimodal SPECT - optical projection tomography (OPT) imaging as an accurate approach to cross-validate radionuclide-based imaging of β-cells. Uptake of a promising radiotracer for β-cell imaging by SPECT, (111)In-exendin-3, was measured by ex vivo-SPECT and cross evaluated by 3D quantitative OPT imaging as well as with histology within healthy and alloxan-treated Brown Norway rat pancreata. SPECT signal was in excellent linear correlation with OPT data as compared to histology. While histological determination of islet spatial distribution was challenging, SPECT and OPT revealed similar distribution patterns of (111)In-exendin-3 and insulin positive β-cell volumes between different pancreatic lobes, both visually and quantitatively. We propose ex vivo SPECT-OPT multimodal imaging as a highly accurate strategy for validating the performance of β-cell radiotracers.

  6. 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

  7. 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.

  8. Assessment of a Pesticide Exposure Intensity Algorithm in the Agricultural Health Study

    EPA Science Inventory

    The accuracy of the exposure assessment is a critical factor in epidemiological investigations of pesticide exposures and health in agricultural populations. However, few studies have been conducted to evaluate questionnaire-based exposure metrics. The Agricultural Health Study...

  9. AN OVERVIEW OF PATHOGEN RESEARCH IN THE MICROBIOLOGICAL AND CHEMICAL EXPOSURE ASSESSMENT RESEARCH DIVISION

    EPA Science Inventory

    The Microbiological and Chemical Exposure Assessment Research Division of the EPA Office of Research and Development's National Exposure Research Laboratory has a robust in-house research program aimed at developing better occurrence and exposure methods for waterborne pathogens....

  10. Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment

    SciTech Connect

    Cowan-Ellsberry, Christina E.; McLachlan, Michael S.; Arnot, Jon A.; MacLeod, Matthew; McKone, Thomas E.; Wania, Frank

    2008-11-01

    Fate and exposure modeling has not thus far been explicitly used in the risk profile documents prepared to evaluate significant adverse effect of candidate chemicals for either the Stockholm Convention or the Convention on Long-Range Transboundary Air Pollution. However, we believe models have considerable potential to improve the risk profiles. Fate and exposure models are already used routinely in other similar regulatory applications to inform decisions, and they have been instrumental in building our current understanding of the fate of POP and PBT chemicals in the environment. The goal of this paper is to motivate the use of fate and exposure models in preparing risk profiles in the POP assessment procedure by providing strategies for incorporating and using models. The ways that fate and exposure models can be used to improve and inform the development of risk profiles include: (1) Benchmarking the ratio of exposure and emissions of candidate chemicals to the same ratio for known POPs, thereby opening the possibility of combining this ratio with the relative emissions and relative toxicity to arrive at a measure of relative risk. (2) Directly estimating the exposure of the environment, biota and humans to provide information to complement measurements, or where measurements are not available or are limited. (3) To identify the key processes and chemical and/or environmental parameters that determine the exposure; thereby allowing the effective prioritization of research or measurements to improve the risk profile. (4) Predicting future time trends including how quickly exposure levels in remote areas would respond to reductions in emissions. Currently there is no standardized consensus model for use in the risk profile context. Therefore, to choose the appropriate model the risk profile developer must evaluate how appropriate an existing model is for a specific setting and whether the assumptions and input data are relevant in the context of the application

  11. Exposure assessment and risk of gastrointestinal illness among surfers.

    PubMed

    Stone, David L; Harding, Anna K; Hope, Bruce K; Slaughter-Mason, Samantha

    2008-01-01

    Surfing is a unique recreational activity with the possibility of elevated risk for contracting gastrointestinal (GI) illness through ingestion of contaminated water. No prior studies have assessed exposure from ingestion among surfing populations. This study estimated the magnitude and frequency of incidental water ingestion using a Web-based survey and integrated exposure distributions with enterococci distributions to predict the probability of GI illness at six Oregon beaches. The mean exposure magnitude and frequency were 170 ml of water ingested per day and 77 days spent surfing per year, respectively. The mean number of enterococci ingested ranged from approximately 11 to 86 colony-forming units (CFU) per day. Exposure-response analyses were conducted using an ingested dose model and two epidemiological models. Risk was characterized using joint probability curves (JPC). At the most contaminated beach, the annualized ingested dose model estimated a mean 9% probability of a 50% probability of GI illness, similar to the results of the first epidemiological model (mean 6% probability of a 50% probability of GI illness). The second epidemiological model predicted a 23% probability of exceeding an exposure equivalent to the U.S. Environmental Protection Agency (EPA) maximum acceptable GI illness rate (19 cases/1000 swimmers). While the annual risk of GI illness for Oregon surfers is not high, data showed that surfers ingest more water compared to swimmers and divers and need to be considered in regulatory and public health efforts, especially in more contaminated waters. Our approach to characterize risk among surfers is novel and informative to officials responsible for advisory programs. It also highlights the need for further research on microbial dose-response relationships to meet the needs of quantitative microbial risk assessments (QMRA).

  12. How to Achieve Accurate Peer Assessment for High Value Written Assignments in a Senior Undergraduate Course

    ERIC Educational Resources Information Center

    Jeffery, Daniel; Yankulov, Krassimir; Crerar, Alison; Ritchie, Kerry

    2016-01-01

    The psychometric measures of accuracy, reliability and validity of peer assessment are critical qualities for its use as a supplement to instructor grading. In this study, we seek to determine which factors related to peer review are the most influential on these psychometric measures, with a primary focus on the accuracy of peer assessment or how…

  13. Exposure Assessment Issues in Epidemiology Studies of Phthalates

    PubMed Central

    Johns, Lauren E.; Cooper, Glinda S.; Galizia, Audrey; Meeker, John D.

    2015-01-01

    Purpose The purpose of this paper is to review exposure assessment issues that need to be addressed in designing and interpreting epidemiology studies of phthalates, a class of chemicals commonly used in consumer and personal care products. Specific issues include population trends in exposure, temporal reliability of a urinary metabolite measurement, and how well a single urine sample may represent longer-term exposure. The focus of this review is on seven specific phthalates: diethyl phthalate (DEP); di-n-butyl phthalate (DBP); diisobutyl phthalate (DiBP); butyl benzyl phthalate (BBzP); di(2-ethylhexyl) phthalate (DEHP); diisononyl phthalate (DiNP); and diisodecyl phthalate (DiDP). Methods Comprehensive literature search using multiple search strategies Results Since 2001, declines in population exposure to DEP, BBzP, DBP, and DEHP have been reported in the United States and Germany, but DEHP exposure has increased in China. Although the half-lives of various phthalate metabolites are relatively short (3 to 18 hours), the intraclass correlation coefficients (ICCs) for phthalate metabolites, based on spot and first morning urine samples collected over a week to several months, range from weak to moderate, with a tendency toward higher ICCs (greater temporal stability) for metabolites of the shorter-chained (DEP, DBP, DiBP and BBzP, ICCs generally 0.3 to 0.6) compared with those of the longer-chained (DEHP, DiNP, DiDP, ICCs generally 0.1 to 0.3) phthalates. Additional research on optimal approaches to addressing the issue of urine dilution in studies of associations between biomarkers and different type of health effects is needed. Conclusions In conclusion, the measurement of urinary metabolite concentrations in urine could serve as a valuable approach to estimating exposure to phthalates in environmental epidemiology studies. Careful consideration of the strengths and limitations of this approach when interpreting study results is required. PMID:26313703

  14. Cross-shift changes in FEV1 in relation to wood dust exposure: the implications of different exposure assessment methods

    PubMed Central

    Schlunssen, V; Sigsgaard, T; Schaumburg, I; Kromhout, H

    2004-01-01

    Background: Exposure-response analyses in occupational studies rely on the ability to distinguish workers with regard to exposures of interest. Aims: To evaluate different estimates of current average exposure in an exposure-response analysis on dust exposure and cross-shift decline in FEV1 among woodworkers. Methods: Personal dust samples (n = 2181) as well as data on lung function parameters were available for 1560 woodworkers from 54 furniture industries. The exposure to wood dust for each worker was calculated in eight different ways using individual measurements, group based exposure estimates, a weighted estimate of individual and group based exposure estimates, and predicted values from mixed models. Exposure-response relations on cross-shift changes in FEV1 and exposure estimates were explored. Results: A positive exposure-response relation between average dust exposure and cross-shift FEV1 was shown for non-smokers only and appeared to be most pronounced among pine workers. In general, the highest slope and standard error (SE) was revealed for grouping by a combination of task and factory size, the lowest slope and SE was revealed for estimates based on individual measurements, with the weighted estimate and the predicted values in between. Grouping by quintiles of average exposure for task and factory combinations revealed low slopes and high SE, despite a high contrast. Conclusion: For non-smokers, average dust exposure and cross-shift FEV1 were associated in an exposure dependent manner, especially among pine workers. This study confirms the consequences of using different exposure assessment strategies studying exposure-response relations. It is possible to optimise exposure assessment combining information from individual and group based exposure estimates, for instance by applying predicted values from mixed effects models. PMID:15377768

  15. Assessment of relative potential for Legionella species or surrogates inhalation exposure from common water uses.

    PubMed

    Hines, Stephanie A; Chappie, Daniel J; Lordo, Robert A; Miller, Brian D; Janke, Robert J; Lindquist, H Alan; Fox, Kim R; Ernst, Hiba S; Taft, Sarah C

    2014-06-01

    The Legionella species have been identified as important waterborne pathogens in terms of disease morbidity and mortality. Microbial exposure assessment is a tool that can be utilized to assess the potential of Legionella species inhalation exposure from common water uses. The screening-level exposure assessment presented in this paper developed emission factors to model aerosolization, quantitatively assessed inhalation exposures of aerosolized Legionella species or Legionella species surrogates while evaluating two generalized levels of assumed water concentrations, and developed a relative ranking of six common in-home uses of water for potential Legionella species inhalation exposure. Considerable variability in the calculated exposure dose was identified between the six identified exposure pathways, with the doses differing by over five orders of magnitude in each of the evaluated exposure scenarios. The assessment of exposure pathways that have been epidemiologically associated with legionellosis transmission (ultrasonic and cool mist humidifiers) produced higher estimated inhalation exposure doses than pathways where epidemiological evidence of transmission has been less strong (faucet and shower) or absent (toilets and therapy pool). With consideration of the large uncertainties inherent in the exposure assessment process used, a relative ranking of exposure pathways from highest to lowest exposure doses was produced using culture-based measurement data and the assumption of constant water concentration across exposure pathways. In this ranking, the ultrasonic and cool mist humidifier exposure pathways were estimated to produce the highest exposure doses, followed by the shower and faucet exposure pathways, and then the toilet and therapy pool exposure pathways.

  16. Physiologically-based pharmacokinetic (PBPK) models in human exposure assessment

    SciTech Connect

    Krishnan, K.

    1995-12-31

    The potential dose received by an individual during defined exposure situations can be determined using personal dosimeters or estimated by combining information on exposure scenarios with the environmental concentration (C.) of chemicals. With the latter approach, not only the potential dose but also the internal dose (i.e., amount of chemical that has been absorbed and available for interaction with receptors) and biologically-effective dose (i.e., amount of chemical that actually reaches the cellular sites where interaction with macromolecules occur) can be estimated if C. is provided as an input to PBPK models. These models are mathematical representations of the interrelationships among the critical determinants of the absorption, distribution, metabolism and excretion of chemicals in biota. Since the compartments in this model correspond to biologically relevant tissues or tissue groups, the amount of chemical reaching specific target organ(s) can be estimated. Further, the PBPK models permit the use of biological monitoring data such as urinary levels of metabolites, hemoglobin adduct levels, and alveolar air concentrations, to reconstruct the exposure levels and scenarios for specific subgroups of populations. These models are also useful in providing estimates of target tissue dose in humans simultaneously exposed to chemicals in various media (air, water, soil, food) by different routes (oral, dermal, inhalation). Several examples of exposure assessment for volatile organic chemicals using PBPK models for mammals will be presented, and the strategies for development of these models for other classes of chemicals highlighted.

  17. Occurrence and exposure assessment of aflatoxins in Catalonia (Spain).

    PubMed

    Cano-Sancho, G; Sanchis, V; Marín, S; Ramos, A J

    2013-01-01

    The main objective of this study was to assess the exposure of Catalonian (Spain) population to AFs. Thus, two sub-objectives were considered: (1) to assess the occurrence of AFs in food marketed in Catalonia, and (2) to assess the consumption of those foods susceptible to AFs contamination by Catalonian population. AFs were analysed in a total of 603 samples considering special commodities as free-gluten, ethnic or baby foods. Analytical method consisted of an extraction and clean-up of aflatoxins step using immunoaffinity columns, and determination by HPLC with post-column photochemical derivatization and fluorescence detection. Food dietary intake was assessed using a food frequency questionnaire, administered to 1387 individuals by trained interviewers. Contamination and consumption raw datasets were combined by means of a direct method and a stochastic method, building the pseudo-parametric bootstrap confidence intervals of the main outputs. Margins of exposure (MoE) and cancer incidence were estimated for the different collectives. The highest percentages of positive samples were found in red pepper, pistachios and peanuts. Considering our results, the most exposed group was the celiac sufferer collective followed by the adolescents; however health concern should not be expected in the population groups.

  18. Estimating exposure and dose to characterize health risks: the role of human tissue monitoring in exposure assessment.

    PubMed Central

    Sexton, K; Callahan, M A; Bryan, E F

    1995-01-01

    Exposure assessment is an integral part of health risk characterization. Exposure assessments typically address three critical aspects of exposure: the number of people exposed to the environmental toxicant, at specific concentrations, for the time period of interest; the resulting dose; and the relative contribution of important sources and pathways to exposure/dose. Because historically both "point-of-contact" measurements and information about dose and related pharmacokinetic processes have been lacking, exposure assessments have had to rely on construction of "scenarios" to estimate exposure and dose. This could change, however, as advances in development of biologic markers of exposure and dose make it possible to measure and interpret toxicant concentrations in accessible human tissues. The increasing availability of "biomarkers," coupled with improvements in pharmacokinetic understanding, present opportunities to estimate ("reconstruct") exposure from measurements of dose and knowledge of intake and uptake parameters. Human tissue monitoring, however, is not a substitute for more traditional methods of measuring exposure, but rather a complementary approach. A combination of exposure measurements and dose measurements provides the most credible scientific basis for exposure assessment. PMID:7635107

  19. Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes

    PubMed Central

    Liu, Bian; Schneider, Samantha; Schwartz, Rebecca; Taioli, Emanuela

    2017-01-01

    Hurricane Sandy caused extensive physical and economic damage; the long-term mental health consequences are unknown. Flooding is a central component of hurricane exposure, influencing mental health through multiple pathways that unfold over months after flooding recedes. Here we assess the concordance in self-reported and Federal Emergency Management (FEMA) flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder (PTSD). Self-reported flood data and mental health symptoms were obtained through validated questionnaires from New York City and Long Island residents (N = 1231) following Sandy. Self-reported flood data was compared to FEMA data obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. Multivariable logistic regressions were performed to determine the relationship between flooding exposure and mental health outcomes. There were significant discrepancies between self-reported and FEMA flood exposure data. Self-reported dichotomous flooding was positively associated with anxiety (ORadj: 1.5 [95% CI: 1.1–1.9]), depression (ORadj: 1.7 [1.3–2.2]), and PTSD (ORadj: 2.5 [1.8–3.4]), while self-reported continuous flooding was associated with depression (ORadj: 1.1 [1.01–1.12]) and PTSD (ORadj: 1.2 [1.1–1.2]). Models with FEMA dichotomous flooding (ORadj: 2.1 [1.5–2.8]) or FEMA continuous flooding (ORadj: 1.1 [1.1–1.2]) were only significantly associated with PTSD. Associations between mental health and flooding vary according to type of flood exposure measure utilized. Future hurricane preparedness and recovery efforts must integrate micro and macro-level flood exposures in order to accurately determine flood exposure risk during storms and realize the long-term importance of flooding on these three mental health symptoms. PMID:28129410

  20. Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes.

    PubMed

    Lieberman-Cribbin, Wil; Liu, Bian; Schneider, Samantha; Schwartz, Rebecca; Taioli, Emanuela

    2017-01-01

    Hurricane Sandy caused extensive physical and economic damage; the long-term mental health consequences are unknown. Flooding is a central component of hurricane exposure, influencing mental health through multiple pathways that unfold over months after flooding recedes. Here we assess the concordance in self-reported and Federal Emergency Management (FEMA) flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder (PTSD). Self-reported flood data and mental health symptoms were obtained through validated questionnaires from New York City and Long Island residents (N = 1231) following Sandy. Self-reported flood data was compared to FEMA data obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. Multivariable logistic regressions were performed to determine the relationship between flooding exposure and mental health outcomes. There were significant discrepancies between self-reported and FEMA flood exposure data. Self-reported dichotomous flooding was positively associated with anxiety (ORadj: 1.5 [95% CI: 1.1-1.9]), depression (ORadj: 1.7 [1.3-2.2]), and PTSD (ORadj: 2.5 [1.8-3.4]), while self-reported continuous flooding was associated with depression (ORadj: 1.1 [1.01-1.12]) and PTSD (ORadj: 1.2 [1.1-1.2]). Models with FEMA dichotomous flooding (ORadj: 2.1 [1.5-2.8]) or FEMA continuous flooding (ORadj: 1.1 [1.1-1.2]) were only significantly associated with PTSD. Associations between mental health and flooding vary according to type of flood exposure measure utilized. Future hurricane preparedness and recovery efforts must integrate micro and macro-level flood exposures in order to accurately determine flood exposure risk during storms and realize the long-term importance of flooding on these three mental health symptoms.

  1. Assessing pesticide exposure of the aquatic environment in tropical catchments

    NASA Astrophysics Data System (ADS)

    Weiss, Frederik; Zurbrügg, Christian; Eggen, Rik; Castillo, Luisa; Ruepert, Clemens; Stamm, Christian

    2015-04-01

    Today, pesticides are intensively used in agriculture across the globe. Worldwide about 2.4×106 tons of pesticides are used annually on 1.6×109 ha of arable land. This yields a global average use of pesticides of 1.53 kg ha-1 year-1. Available data suggest that the use in the agricultural sector will continue to grow. Recently it was estimated that within the last decade, the world pesticide market increased by 93% and the Brazilian market alone by 190%. Though pesticides are intensively used in many low and middle income countries (LAMICs), scientifically sound data of amounts and types of pesticide use and the resulting impact on water quality are lacking in many of these countries. Therefore it is highly relevant to: i) identify risk areas where pesticides affect environmental health, ii) understand the environmental behavior of pesticides in vulnerable tropical ecosystems; and iii) develop possible mitigation options to reduce their exposure to ecosystems and humans. Here we present a project that will focus on assessing pesticide exposure of the aquatic environment and humans in tropical catchments of LAMICs. A catchment in the Zarcero province in Costa Rica will be the test case. Pesticide exposure will be assessed by passive sampling. In order to cover a broad range of compounds of possible use, two sampling devices will be used: SDB membranes for collecting polar compounds and silicon sheets for accumulating apolar pesticides. Extracts will be subsequently analysed by GC-MSMS and LC-HRMS.

  2. Comparison of residents' pesticide exposure with predictions obtained using the UK regulatory exposure assessment approach.

    PubMed

    Galea, Karen S; MacCalman, Laura; Jones, Kate; Cocker, John; Teedon, Paul; Cherrie, John W; van Tongeren, Martie

    2015-11-01

    The UK regulatory methods currently used for estimating residents' potential pesticide exposure were assessed to determine whether they provide sufficiently conservative estimates. A non-random sample of 149 residents living within 100 m of fields where pesticides were sprayed provided first morning void urine samples one and/or two days after spraying. Using farmers' spray information, regulatory exposure assessment (REA) models were applied to estimate potential pesticide intake among residents, with a toxicokinetic (TK) model used to estimate urinary biomarker concentrations in the mornings of the two days following the spray. These were compared with actual measured urinary biomarker concentrations obtained following the spray applications. The study focused on five pesticides (cypermethrin, penconazole, captan, chlorpyrifos and chlormequat). All measured cypermethrin urinary biomarker levels were lower than the REA-predicted concentrations. Over 98% and 97% of the measured urinary biomarker concentrations for penconazole and captan respectively were lower than the REA-predicted exposures. Although a number of the chlorpyrifos and chlormequat spray-related urinary biomarker concentrations were greater than the predictions, investigation of the background urinary biomarker concentrations suggests these were not significantly different from the levels expected had no pesticide spraying occurred. The majority of measured concentrations being well below the REA-predicted concentrations indicate that, in these cases, the REA is sufficiently conservative.

  3. AN OVERVIEW OF THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) PHASE I STUDIES

    EPA Science Inventory

    The National Human Exposure Assessment Survey (NHEXAS) Phase I studies were sponsored by EPA's Office of Research and Development (ORD) to address critical information needs for assessing human exposures to multiple chemicals from multiple pathways and media. These studies were...

  4. Radiation exposure and risk assessment for critical female body organs

    SciTech Connect

    Atwell, W.; Weyland, M.D.; Hardy, A.C. NASA, Johnson Space Center, Houston, TX )

    1991-07-01

    Space radiation exposure limits for astronauts are based on recommendations of the National Council on Radiation Protection and Measurements. These limits now include the age at exposure and sex of the astronaut. A recently-developed computerized anatomical female (CAF) model is discussed in detail. Computer-generated, cross-sectional data are presented to illustrate the completeness of the CAF model. By applying ray-tracing techniques, shield distribution functions have been computed to calculate absorbed dose and dose equivalent values for a variety of critical body organs (e.g., breasts, lungs, thyroid gland, etc.) and mission scenarios. Specific risk assessments, i.e., cancer induction and mortality, are reviewed. 13 refs.

  5. Exposure assessment of natural uranium from drinking water.

    PubMed

    Jakhu, Rajan; Mehra, Rohit; Mittal, H M

    2016-12-08

    The uranium concentration in the drinking water of the residents of the Jaipur and Ajmer districts of Rajasthan has been measured for exposure assessment. The daily intake of uranium from the drinking water for the residents of the study area is found to vary from 0.4 to 123.9 μg per day. For the average uranium ingestion rate of 35.2 μg per day for a long term exposure period of 60 years, estimations have been made for the retention of uranium in different body organs and its excretion with time using ICRP's biokinetic model of uranium. Radioactive and chemical toxicity of uranium has been reported and discussed in detail in the present manuscript.

  6. Glove accumulation of pesticide residues for strawberry harvester exposure assessment.

    PubMed

    Li, Yanhong; Chen, Li; Chen, Zhenshan; Coehlo, Joe; Cui, Li; Liu, Yu; Lopez, Terry; Sankaran, Gayatri; Vega, Helen; Krieger, Robert

    2011-06-01

    We investigated the accumulation of pesticide residues on rubber latex gloves that are used by strawberry harvesters to protect their skin, reduce pesticide exposure and promote food safety. Gloves accumulated residues of 16 active ingredients including azoxystrobin, bifenthrin, boscalid, captan, cyprodinil, fenhexamid, fenpropathrin, fludioxonil, hexythiazox, malathion, methomyl, naled, propiconazole, pyraclostrobin, quinoline, and quinoxyfen at different times. Glove residue accumulation (t(½) 2.8-3.7 d) was very similar to the dissipation of DFRs (t(½) 2.1-3.0 d) during the first 3 weeks after malathion applications. Dermal malathion dose was 0.2 mg/kg at the preharvest interval and declined to trace levels during the following 3 months. Glove accumulation of malathion indicated trace surface residue availability and was used to assess the relationship between dislodgable foliar residues and potential hand exposure.

  7. Mapping of fluoride endemic areas and assessment of fluoride exposure.

    PubMed

    Viswanathan, Gopalan; Jaswanth, A; Gopalakrishnan, S; Siva ilango, S

    2009-02-15

    The prevalence of fluorosis is mainly due to the consumption of more fluoride through drinking water. It is necessary to find out the fluoride endemic areas to adopt remedial measures to the people on the risk of fluorosis. The objectives of this study are to estimate the fluoride exposure through drinking water from people of different age group and to elucidate the fluoride endemic areas through mapping. Assessment of fluoride exposure was achieved through the estimation fluoride level in drinking water using fluoride ion selective electrode method. Google earth and isopleth technique were used for mapping of fluoride endemic areas. From the study it was observed that Nilakottai block of Dindigul district in Tamil Nadu is highly fluoride endemic. About 88% of the villages in this block have fluoride level more than the prescribed permissible limit in drinking water. Exposure of fluoride among different age groups was calculated in this block, which comprises 32 villages. The maximum estimated exposure doses were 0.19 mg/kg/day for infants, 0.17 mg/kg/day for children and 0.10 mg/kg/day for adults. When compared with adequate intake of minimal safe level exposure dose of 0.01 mg/kg/day for infants and 0.05 mg/kg/day for other age groups, a health risk due to fluorosis to the people in Nilakottai block has become evident. From the results, the people in Nilakottai block are advised to consume drinking water with fluoride level less than 1 mg/l. It has been recommended to the government authorities to take serious steps to supply drinking water with low fluoride concern for the fluorosis affected villages.

  8. Assessment of cancer risks due to environmental exposure to asbestos.

    PubMed

    Driece, Hermen A L; Siesling, Sabine; Swuste, Paul H J J; Burdorf, Alex

    2010-07-01

    In a rural area widespread pollution of friable and non-friable waste products was present, used to harden dirt tracks, yards, and driveways during 1935-1974. Exposure to environmental asbestos was assessed by a site approach, based on number of polluted sites within postal code areas, and by a household approach, based on number of households in the close vicinity to polluted sites within postal code areas. Based on asbestos soil investigations, 293 sites were identified with asbestos waste material at the surface, of which 77% contained crocidolite fibres as well as chrysotile fibres. The 293 sites-at-risk varied from 5 m(2) to 2722 m(2) and were surrounded by 347 households within 100 m of these sites. Distance to the plant was associated with the number of sites (r=0.36), and with the number of households (r=0.52). However, categorization of postal code areas into low, intermediate or high likelihood of exposure to asbestos showed a modest agreement between the site and household approach. In the site approach a total of 2.3 million person-years at risk were estimated with an average exposure of 1674 fibres/m(3) and an expected 1.8 cases of malignant mesothelioma each year. The household approach resulted in estimates of 1.2 million person-years at risk, and 0.9 cases of malignant mesothelioma per year, respectively. This study illustrates that asbestos waste on the surface of roads and yards in an area with over 130,000 inhabitants may result in long-term exposure to asbestos that will cause several cases of malignant mesothelioma each year. Although distance to plant, number of polluted sites and number of exposed household were associated, the modest agreement among these measures of exposure indicate that the exposure assessment strategy chosen in a particular study may result in considerable misclassification. Without detailed information on individual behaviour within the polluted area, it is difficult to show that a more individually oriented approach

  9. Assessment of mycotoxin exposure in the Belgian population using biomarkers: aim, design and methods of the BIOMYCO study.

    PubMed

    Heyndrickx, Ellen; Sioen, Isabelle; Bellemans, Mia; De Maeyer, Mieke; Callebaut, Alfons; De Henauw, Stefaan; De Saeger, Sarah

    2014-01-01

    Mycotoxins are harmful food contaminants. Currently, human exposure assessment to these toxins is often based on calculations combining mycotoxin occurrence data in food with population data on food consumption. Because of limitations inherent to that approach, biomarkers have been proposed as a suitable alternative whereby a more accurate assessment of exposure at the individual level can be performed. The BIOMYCO study is designed to assess human mycotoxin exposure using urinary biomarkers of exposure. Over the different seasons of 2013 and 2014, morning urine is gathered in a representative part of the Belgian population according to a designed study protocol, whereby 140 children (3-12 years old) and 278 adults (19-65 years old) are selected based on random cluster sampling stratified for sex, age and geographical areas. Every participant completes a food frequency questionnaire to assess the consumption of relevant foodstuffs (n = 43) of both the day before the urine collection and the previous month. Validated multi-toxin LC-MS/MS methods are used to analyse aflatoxins, fumonisins, ochratoxin A, trichothecenes, zearalenone and their metabolites in morning urine. The study protocol is approved by the ethical committee of the Ghent University Hospital. Within this paper, study design and methods are described. The BIOMYCO study is the first study whereby a multi-toxin approach is applied for mycotoxin exposure assessment in adults and children on a large scale. Moreover, it is the first study that will describe the exposure to an elaborated set of mycotoxins in the Belgian population. In first instance, descriptive analysis will be performed, describing the exposure to mycotoxins for the child and adult group. Exposure of different subgroups will be compared. Furthermore, correlations between the mycotoxin concentrations measured and the food consumption reported will be estimated to explore whether the mycotoxin exposure could be explained by the consumption

  10. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling

    SciTech Connect

    Aerts, Sam Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-10-15

    In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information—inside hotspots or in search of them—based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km{sup 2}. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an

  11. Assessment of exposure to mixture pollutants in Mexican indigenous children.

    PubMed

    Flores-Ramírez, R; Pérez-Vázquez, F J; Cilia-López, V G; Zuki-Orozco, B A; Carrizales, L; Batres-Esquivel, L E; Palacios-Ramírez, A; Díaz-Barriga, F

    2016-05-01

    The aim of the present work was to complete an exposure assessment in three Mexican indigenous communities using the community-based health risk assessment, which is the first step in the CHILD framework. We used 1-hydroxypyrene (1-OHP) as an exposure biomarker to polycyclic aromatic hydrocarbons (PAHs) and trans, trans-muconic acid (t,t-MA) as an exposure biomarker to benzene, persistent organic pollutants (POPs), lead, manganese, arsenic, and fluoride. Anthropometric measurements were also taken. In these communities, high percentages of children with chronic malnutrition were found (28 to 49 %) based on their weight and age. All communities showed a high percentage of children with detectable levels of four or more compounds (70 to 82 %). Additionally, our results showed that in indigenous communities, children are exposed to elevated levels of certain environmental pollutants, including manganese with 17.6, 16.8, and 7.3 μg/L from SMP, TOC, and CUA, respectively. Lead and HCB levels were similar in the indigenous communities (2.5, 3.1, and 4.2 μg/dL and 2.5, 3.1, and 3.7 ng/mL, respectively). 1-OHP and t,t-MA levels were higher in TOC (0.8 μmol/mol of creatinine, 476 μg/g of creatinine, respectively) when compared with SMP (0.1 μmol/mol of creatinine, 215.5 μg/g of creatinine, respectively) and CUA (0.1 μmol/mol of creatinine, 185.2 μg/g of creatinine, respectively). DDE levels were 30.7, 26.9, and 9.6 ng/mL in CUA, SMP, and TOC, respectively. The strength of this study is that it assesses exposure to pollutants with indications for the resultant risk before an intervention is made by the CHILD program to manage this risk in the indigenous communities. Considering the large number of people, especially children, exposed to multiple pollutants, it is important to design effective intervention programs that reduce exposure and the resultant risk in the numerous indigenous communities in Mexico.

  12. Plasma miRNA as biomarkers for assessment of total-body radiation exposure dosimetry.

    PubMed

    Cui, Wanchang; Ma, Jinfang; Wang, Yulei; Biswal, Shyam

    2011-01-01

    The risk of radiation exposure, due to accidental or malicious release of ionizing radiation, is a major public health concern. Biomarkers that can rapidly identify severely-irradiated individuals requiring prompt medical treatment in mass-casualty incidents are urgently needed. Stable blood or plasma-based biomarkers are attractive because of the ease for sample collection. We tested the hypothesis that plasma miRNA expression profiles can accurately reflect prior radiation exposure. We demonstrated using a murine model that plasma miRNA expression signatures could distinguish mice that received total body irradiation doses of 0.5 Gy, 2 Gy, and 10 Gy (at 6 h or 24 h post radiation) with accuracy, sensitivity, and specificity of above 90%. Taken together, these data demonstrate that plasma miRNA profiles can be highly predictive of different levels of radiation exposure. Thus, plasma-based biomarkers can be used to assess radiation exposure after mass-casualty incidents, and it may provide a valuable tool in developing and implementing effective countermeasures.

  13. Assessing temporal flux of plant hormones in stored processing potatoes using high definition accurate mass spectrometry

    PubMed Central

    Ordaz-Ortiz, José Juan; Foukaraki, Sofia; Terry, Leon Alexander

    2015-01-01

    Plant hormones are important molecules which at low concentration can regulate various physiological processes. Mass spectrometry has become a powerful technique for the quantification of multiple classes of plant hormones because of its high sensitivity and selectivity. We developed a new ultrahigh pressure liquid chromatography–full-scan high-definition accurate mass spectrometry method, for simultaneous determination of abscisic acid and four metabolites phaseic acid, dihydrophaseic acid, 7′-hydroxy-abscisic acid and abscisic acid glucose ester, cytokinins zeatin, zeatin riboside, gibberellins (GA1, GA3, GA4 and GA7) and indole-3-acetyl-L-aspartic acid. We measured the amount of plant hormones in the flesh and skin of two processing potato cvs. Sylvana and Russet Burbank stored for up to 30 weeks at 6 °C under ambient air conditions. Herein, we report for the first time that abscisic acid glucose ester seems to accumulate in the skin of potato tubers throughout storage time. The method achieved a lowest limit of detection of 0.22 ng g−1 of dry weight and a limit of quantification of 0.74 ng g−1 dry weight (zeatin riboside), and was able to recover, detect and quantify a total of 12 plant hormones spiked on flesh and skin of potato tubers. In addition, the mass accuracy for all compounds (<5 ppm) was evaluated. PMID:26504563

  14. Assessing temporal flux of plant hormones in stored processing potatoes using high definition accurate mass spectrometry.

    PubMed

    Ordaz-Ortiz, José Juan; Foukaraki, Sofia; Terry, Leon Alexander

    2015-01-01

    Plant hormones are important molecules which at low concentration can regulate various physiological processes. Mass spectrometry has become a powerful technique for the quantification of multiple classes of plant hormones because of its high sensitivity and selectivity. We developed a new ultrahigh pressure liquid chromatography-full-scan high-definition accurate mass spectrometry method, for simultaneous determination of abscisic acid and four metabolites phaseic acid, dihydrophaseic acid, 7'-hydroxy-abscisic acid and abscisic acid glucose ester, cytokinins zeatin, zeatin riboside, gibberellins (GA1, GA3, GA4 and GA7) and indole-3-acetyl-L-aspartic acid. We measured the amount of plant hormones in the flesh and skin of two processing potato cvs. Sylvana and Russet Burbank stored for up to 30 weeks at 6 °C under ambient air conditions. Herein, we report for the first time that abscisic acid glucose ester seems to accumulate in the skin of potato tubers throughout storage time. The method achieved a lowest limit of detection of 0.22 ng g(-1) of dry weight and a limit of quantification of 0.74 ng g(-1) dry weight (zeatin riboside), and was able to recover, detect and quantify a total of 12 plant hormones spiked on flesh and skin of potato tubers. In addition, the mass accuracy for all compounds (<5 ppm) was evaluated.

  15. Risk assessment of consuming agricultural products irrigated with reclaimed wastewater: An exposure model

    NASA Astrophysics Data System (ADS)

    van Ginneken, Meike; Oron, Gideon

    2000-09-01

    This study assesses health risks to consumers due to the use of agricultural products irrigated with reclaimed wastewater. The analysis is based on a definition of an exposure model which takes into account several parameters: (1) the quality of the applied wastewater, (2) the irrigation method, (3) the elapsed times between irrigation, harvest, and product consumption, and (4) the consumers' habits. The exposure model is used for numerical simulation of human consumers' risks using the Monte Carlo simulation method. The results of the numerical simulation show large deviations, probably caused by uncertainty (impreciseness in quality of input data) and variability due to diversity among populations. There is a 10-orders of magnitude difference in the risk of infection between the different exposure scenarios with the same water quality. This variation indicates the need for setting risk-based criteria for wastewater reclamation rather than single water quality guidelines. Extra data are required to decrease uncertainty in the risk assessment. Future research needs to include definition of acceptable risk criteria, more accurate dose-response modeling, information regarding pathogen survival in treated wastewater, additional data related to the passage of pathogens into and in the plants during irrigation, and information regarding the behavior patterns of the community of human consumers.

  16. Assessment of exposure to the Penicillium glabrum complex in cork industry using complementing methods.

    PubMed

    Viegas, Carla; Sabino, Raquel; Botelho, Daniel; dos Santos, Mateus; Gomes, Anita Quintal

    2015-09-01

    Cork oak is the second most dominant forest species in Portugal and makes this country the world leader in cork export. Occupational exposure to Chrysonilia sitophila and the Penicillium glabrum complex in cork industry is common, and the latter fungus is associated with suberosis. However, as conventional methods seem to underestimate its presence in occupational environments, the aim of our study was to see whether information obtained by polymerase chain reaction (PCR), a molecular-based method, can complement conventional findings and give a better insight into occupational exposure of cork industry workers. We assessed fungal contamination with the P. glabrum complex in three cork manufacturing plants in the outskirts of Lisbon using both conventional and molecular methods. Conventional culturing failed to detect the fungus at six sampling sites in which PCR did detect it. This confirms our assumption that the use of complementing methods can provide information for a more accurate assessment of occupational exposure to the P. glabrum complex in cork industry.

  17. A new noninvasive method for the accurate and precise assessment of varicose vein diameters.

    PubMed

    Baldassarre, Damiano; Pustina, Linda; Castelnuovo, Samuela; Bondioli, Alighiero; Carlà, Matteo; Sirtori, Cesare R

    2003-01-01

    The feasibility and reproducibility of a new ultrasonic method for the direct assessment of maximal varicose vein diameter (VVD) were evaluated. A study was also performed to demonstrate the capacity of the method to detect changes in venous diameter induced by a pharmacologic treatment. Patients with varicose vein disease were recruited. A method that allows the precise positioning of patient and transducer and performance of scans in a gel-bath was developed. Maximal VVD was recorded both in the standing and supine positions. The intraassay reproducibility was determined by replicate scans made within 15 minutes in both positions. The interobserver variability was assessed by comparing VVDs measured during the first phase baseline examination with those obtained during baseline examinations in the second phase of the study. The error in reproducibility of VVD determinations was 5.3% when diameters were evaluated in the standing position and 6.4% when assessed in the supine position. The intramethod agreement was high, with a bias between readings of 0.06 +/- 0.18 mm and of -0.02 +/- 0.19 mm, respectively, in standing and supine positions. Correlation coefficients were better than 0.99 in both positions. The method appears to be sensitive enough to detect small changes in VVDs induced by treatments. The proposed technique provides a tool of potential valid use in the detection and in vivo monitoring of VVD changes in patients with varicose vein disease. The method offers an innovative approach to obtain a quantitative assessment of varicose vein progression and of treatment effects, thus providing a basis for epidemiologic surveys.

  18. Genomic Models of Short-Term Exposure Accurately Predict Long-Term Chemical Carcinogenicity and Identify Putative Mechanisms of Action

    PubMed Central

    Gusenleitner, Daniel; Auerbach, Scott S.; Melia, Tisha; Gómez, Harold F.; Sherr, David H.; Monti, Stefano

    2014-01-01

    Background Despite an overall decrease in incidence of and mortality from cancer, about 40% of Americans will be diagnosed with the disease in their lifetime, and around 20% will die of it. Current approaches to test carcinogenic chemicals adopt the 2-year rodent bioassay, which is costly and time-consuming. As a result, fewer than 2% of the chemicals on the market have actually been tested. However, evidence accumulated to date suggests that gene expression profiles from model organisms exposed to chemical compounds reflect underlying mechanisms of action, and that these toxicogenomic models could be used in the prediction of chemical carcinogenicity. Results In this study, we used a rat-based microarray dataset from the NTP DrugMatrix Database to test the ability of toxicogenomics to model carcinogenicity. We analyzed 1,221 gene-expression profiles obtained from rats treated with 127 well-characterized compounds, including genotoxic and non-genotoxic carcinogens. We built a classifier that predicts a chemical's carcinogenic potential with an AUC of 0.78, and validated it on an independent dataset from the Japanese Toxicogenomics Project consisting of 2,065 profiles from 72 compounds. Finally, we identified differentially expressed genes associated with chemical carcinogenesis, and developed novel data-driven approaches for the molecular characterization of the response to chemical stressors. Conclusion Here, we validate a toxicogenomic approach to predict carcinogenicity and provide strong evidence that, with a larger set of compounds, we should be able to improve the sensitivity and specificity of the predictions. We found that the prediction of carcinogenicity is tissue-dependent and that the results also confirm and expand upon previous studies implicating DNA damage, the peroxisome proliferator-activated receptor, the aryl hydrocarbon receptor, and regenerative pathology in the response to carcinogen exposure. PMID:25058030

  19. Mercury contamination and exposure assessment of fishery products in Korea.

    PubMed

    Yang, Hye-Ran; Kim, Na-Young; Hwang, Lae-Hong; Park, Ju-Sung; Kim, Jung-Hun

    2015-01-01

    In this study, total (T-Hg) and methyl mercury (Me-Hg) contamination was investigated in fishery products including canned fish, fish sauces, dried bonito and frozen tuna sashimi, collected from retail markets in Korea, to assess dietary exposure. Direct mercury analyser and gas chromatography-electron captured detector were employed to measure T-Hg and Me-Hg, respectively. The highest T-Hg and Me-Hg contamination was present in tuna sashimi, followed by dried bonito, respectively. Canned tuna showed more frequent detection and higher content than other canned fishery products. The weekly exposure estimate indicates that exposure to mercury from fishery products is safe, showing 2.59% provisional tolerable weekly intake (PTWI) for T-Hg, 1.82% PTWI for Me-Hg and 4.16% reference dose for Me-Hg. However, it should be addressed to monitor the mercury contamination in fish and fishery products regularly, to safeguard vulnerable population such as children, to limit intake of these food products.

  20. Modeling residential fine particulate matter infiltration for exposure assessment.

    PubMed

    Hystad, Perry U; Setton, Eleanor M; Allen, Ryan W; Keller, Peter C; Brauer, Michael

    2009-09-01

    Individuals spend the majority of their time indoors; therefore, estimating infiltration of outdoor-generated fine particulate matter (PM(2.5)) can help reduce exposure misclassification in epidemiological studies. As indoor measurements in individual homes are not feasible in large epidemiological studies, we evaluated the potential of using readily available data to predict infiltration of ambient PM(2.5) into residences. Indoor and outdoor light scattering measurements were collected for 84 homes in Seattle, Washington, USA, and Victoria, British Columbia, Canada, to estimate residential infiltration efficiencies. Meteorological variables and spatial property assessment data (SPAD), containing detailed housing characteristics for individual residences, were compiled for both study areas using a geographic information system. Multiple linear regression was used to construct models of infiltration based on these data. Heating (October to February) and non-heating (March to September) season accounted for 36% of the yearly variation in detached residential infiltration. Two SPAD housing characteristic variables, low building value, and heating with forced air, predicted 37% of the variation found between detached residential infiltration during the heating season. The final model, incorporating temperature and the two SPAD housing characteristic variables, with a seasonal interaction term, explained 54% of detached residential infiltration. Residences with low building values had higher infiltration efficiencies than other residences, which could lead to greater exposure gradients between low and high socioeconomic status individuals than previously identified using only ambient PM(2.5) concentrations. This modeling approach holds promise for incorporating infiltration efficiencies into large epidemiology studies, thereby reducing exposure misclassification.

  1. Cost/variance optimization for human exposure assessment studies.

    PubMed

    Whitmore, Roy W; Pellizzari, Edo D; Zelon, Harvey S; Michael, Larry C; Quackenboss, James J

    2005-11-01

    The National Human Exposure Assessment Survey (NHEXAS) field study in EPA Region V (one of three NHEXAS field studies) provides extensive exposure data on a representative sample of 249 residents of the Great Lakes states. Concentration data were obtained for both metals and volatile organic compounds (VOCs) from multiple environmental media and from human biomarkers. A variance model for the logarithms of concentration measurements is used to define intraclass correlations between observations within primary sampling units (PSUs) (nominally counties) and within secondary sampling units (SSUs) (nominally Census blocks). A model for the total cost of the study is developed in terms of fixed costs and variable costs per PSU, SSU, and participant. Intraclass correlations are estimated for media and analytes with sufficient sample sizes. We demonstrate how the intraclass correlations and variable cost components can be used to determine the sample allocation that minimizes cost while achieving pre-specified precision constraints for future studies that monitor environmental concentrations and human exposures for metals and VOCs.

  2. Exposure assessment of workers in printed electronics workplace.

    PubMed

    Lee, Ji Hyun; Sohn, Eun Kyung; Ahn, Jin Soo; Ahn, Kangho; Kim, Keun Soo; Lee, Jong Hwan; Lee, Taik Min; Yu, Il Je

    2013-07-01

    Printed electronics uses converging technologies, such as printing, fine mechanics, nanotechnology, electronics and other new technologies. Consequently, printed electronics raises additional health and safety concerns to those experienced in the traditional printing industry. This study investigated two printed electronics workplaces based on a walk-through survey and personal and area sampling. All the printed electronics operations were conducted in a cleanroom. No indication of exposure to excess silver nanoparticles or carbon nanotubes (CNTs) was found. While the organic solvents were lower than current occupational exposure limits, there was a lack of engineering controls, such as local exhaust ventilation, correct enclosure and duct connections. There was also an insufficient quantity of personal protective equipment, and some organic solvents not described in the safety data sheets (SDSs) were detected in the air samples. Plus, the cleaning work, a major emissions operation, was not conducted within a hood, and the cleaning waste was not properly disposed of. Therefore, the present exposure assessment results from two printed electronics workplaces suggest that the printed electronics industry needs to take note of the occupational safety and health risks and hazards already established by the traditional printing industry, along with new risks and hazards originating from converging technologies such as nanotechnology.

  3. Dietary exposure to copper in the European Union and its assessment for EU regulatory risk assessment.

    PubMed

    Sadhra, Steven S; Wheatley, Andrew D; Cross, Hilary J

    2007-03-15

    EU legislation requires a multimedia exposure assessment for substances supplied within the EU. Dietary intake is the main source of exposure for the majority of the population hence an essential component of the human risk assessment. This paper describes the available data for dietary copper and its use in estimating daily intake including variability and determinants of exposure. Typical and reasonable worst-case estimates are derived for the general population from the available peer reviewed literature. Intakes from drinking water are found to exhibit more variability than those from food. Therefore, different exposure scenarios are derived to reflect the range of acute and chronic exposures that may occur. Estimates of typical copper intakes for the EU population are in the range 0.8-1.8 mg/day. Typical copper intakes of men are higher than those of women while the intake among the general adult population is higher than that of the elderly. Intakes of both men and women are generally close to the WHO normative requirements but may be somewhat lower in specific locations where background levels of copper are unusually low. Alcoholic beverages represent minor contribution daily copper intakes. Intakes for children are rather variable ranging broadly from 0.7 to 1.5 mg/day and are somewhat age and sex dependent. Greater uncertainty applies to the assessment of local exposure incorporating food produced on land directly impacted by contemporary copper industry emissions. Specifically, the extent to which soil is enriched in copper in these conditions is unclear. However, effective homeostatic control mechanisms in plants limit uptake and transfer to the human food chain. A best estimate of 0.25 mg/day in addition to regional exposure was derived. Drinking water is estimated to contribute only marginally to total copper intake in most cases. Higher intakes may occur in areas of poor water quality and/or corroded distribution systems. Such elevated exposures

  4. Assessing the effects of sodium hypochlorite exposure on the characteristics of PVDF based membranes.

    PubMed

    Abdullah, Syed Z; Bérubé, Pierre R

    2013-09-15

    Sodium hypochlorite is commonly used as a cleaning agent to remove adsorbed foulants from PVDF based micro/ultra filtration membranes in water and wastewater treatment applications. Although effective for fouling control, extended sodium hypochlorite exposure can affect the physical/chemical characteristics and hinder the treatment performance of these membranes. To assess these effects, PVDF based membranes were exposed to sodium hypochlorite at different concentrations for varying periods of time, and the physical/chemical characteristics of the virgin and sodium hypochlorite exposed membranes were compared. The membranes were characterized based on chemical composition (FTIR and NMR), mechanical strength (yield strength), surface hydrophilicity (contact angle), pore size and porosity (scanning electron microscopy and challenge test), and membrane resistance (clean water permeation test). The results indicated that exposure dose and concentration of the sodium hypochlorite used have significant influence on the membrane characteristics. The impact of sodium hypochlorite exposure on the parameters investigated could be most accurately and consistently correlated to an exposure dose relationship of the form C(n)t (where, C = concentration and t = exposure time) rather than the Ct relationship commonly used to define the extent of exposure to cleaning agents. For all the parameters investigated, the power coefficient n was less than 1 indicating that time had a greater impact on the changes than did the concentration of the sodium hypochlorite. The results suggest that the use of sodium hypochlorite for chemical cleaning, at concentrations that are higher than those typically used for chemical cleaning would have less of an effect on the characteristics of the membrane materials. Changes in the characteristics were attributed to the oxidation of the hydrophilic additives (HA) present in blended PVDF membranes.

  5. Serum Protein Profile at Remission Can Accurately Assess Therapeutic Outcomes and Survival for Serous Ovarian Cancer

    PubMed Central

    Ghamande, Sharad A.; Bush, Stephen; Ferris, Daron; Zhi, Wenbo; He, Mingfang; Wang, Meiyao; Wang, Xiaoxiao; Miller, Eric; Hopkins, Diane; Macfee, Michael; Guan, Ruili; Tang, Jinhai; She, Jin-Xiong

    2013-01-01

    Background Biomarkers play critical roles in early detection, diagnosis and monitoring of therapeutic outcome and recurrence of cancer. Previous biomarker research on ovarian cancer (OC) has mostly focused on the discovery and validation of diagnostic biomarkers. The primary purpose of this study is to identify serum biomarkers for prognosis and therapeutic outcomes of ovarian cancer. Experimental Design Forty serum proteins were analyzed in 70 serum samples from healthy controls (HC) and 101 serum samples from serous OC patients at three different disease phases: post diagnosis (PD), remission (RM) and recurrence (RC). The utility of serum proteins as OC biomarkers was evaluated using a variety of statistical methods including survival analysis. Results Ten serum proteins (PDGF-AB/BB, PDGF-AA, CRP, sFas, CA125, SAA, sTNFRII, sIL-6R, IGFBP6 and MDC) have individually good area-under-the-curve (AUC) values (AUC = 0.69–0.86) and more than 10 three-marker combinations have excellent AUC values (0.91–0.93) in distinguishing active cancer samples (PD & RC) from HC. The mean serum protein levels for RM samples are usually intermediate between HC and OC patients with active cancer (PD & RC). Most importantly, five proteins (sICAM1, RANTES, sgp130, sTNFR-II and sVCAM1) measured at remission can classify, individually and in combination, serous OC patients into two subsets with significantly different overall survival (best HR = 17, p<10−3). Conclusion We identified five serum proteins which, when measured at remission, can accurately predict the overall survival of serous OC patients, suggesting that they may be useful for monitoring the therapeutic outcomes for ovarian cancer. PMID:24244307

  6. Chromatography paper as a low-cost medium for accurate spectrophotometric assessment of blood hemoglobin concentration.

    PubMed

    Bond, Meaghan; Elguea, Carlos; Yan, Jasper S; Pawlowski, Michal; Williams, Jessica; Wahed, Amer; Oden, Maria; Tkaczyk, Tomasz S; Richards-Kortum, Rebecca

    2013-06-21

    Anemia affects a quarter of the world's population, and a lack of appropriate diagnostic tools often prevents treatment in low-resource settings. Though the HemoCue 201+ is an appropriate device for diagnosing anemia in low-resource settings, the high cost of disposables ($0.99 per test in Malawi) limits its availability. We investigated using spectrophotometric measurement of blood spotted on chromatography paper as a low-cost (<$0.01 per test) alternative to HemoCue cuvettes. For this evaluation, donor blood was diluted with plasma to simulate anemia, a micropipette spotted blood on paper, and a bench-top spectrophotometer validated the approach before the development of a low-cost reader. We optimized impregnating paper with chemicals to lyse red blood cells, paper type, drying time, wavelengths measured, and sensitivity to variations in volume of blood, and we validated our approach using patient samples. Lysing the blood cells with sodium deoxycholate dried in Whatman Chr4 chromatography paper gave repeatable results, and the absorbance difference between 528 nm and 656 nm was stable over time in measurements taken up to 10 min after sample preparation. The method was insensitive to the amount of blood spotted on the paper over the range of 5 μL to 25 μL. We created a low-cost, handheld reader to measure the transmission of paper cuvettes at these optimal wavelengths. Training and validating our method with patient samples on both the spectrometer and the handheld reader showed that both devices are accurate to within 2 g dL(-1) of the HemoCue device for 98% and 95% of samples, respectively.

  7. Aggregate versus individual-level sexual behavior assessment: how much detail is needed to accurately estimate HIV/STI risk?

    PubMed

    Pinkerton, Steven D; Galletly, Carol L; McAuliffe, Timothy L; DiFranceisco, Wayne; Raymond, H Fisher; Chesson, Harrell W

    2010-02-01

    The sexual behaviors of HIV/sexually transmitted infection (STI) prevention intervention participants can be assessed on a partner-by-partner basis: in aggregate (i.e., total numbers of sex acts, collapsed across partners) or using a combination of these two methods (e.g., assessing five partners in detail and any remaining partners in aggregate). There is a natural trade-off between the level of sexual behavior detail and the precision of HIV/STI acquisition risk estimates. The results of this study indicate that relatively simple aggregate data collection techniques suffice to adequately estimate HIV risk. For highly infectious STIs, in contrast, accurate STI risk assessment requires more intensive partner-by-partner methods.

  8. Assessing the Health and Performance Risks of Carbon Dioxide Exposures

    NASA Technical Reports Server (NTRS)

    James, John T.; Meyers, V. E.; Alexander, D.

    2010-01-01

    provide no more than partial answers to the questions of environmental interactions, interindividual variability, and optimal control levels. Future prospective studies should involve assessment of astronaut well being using sophisticated measures during exposures to levels of CO2 in the range from 2 to 8 mmHg.

  9. Assessing Mammal Exposure to Climate Change in the Brazilian Amazon.

    PubMed

    Ribeiro, Bruno R; Sales, Lilian P; De Marco, Paulo; Loyola, Rafael

    2016-01-01

    Human-induced climate change is considered a conspicuous threat to biodiversity in the 21st century. Species' response to climate change depends on their exposition, sensitivity and ability to adapt to novel climates. Exposure to climate change is however uneven within species' range, so that some populations may be more at risk than others. Identifying the regions most exposed to climate change is therefore a first and pivotal step on determining species' vulnerability across their geographic ranges. Here, we aimed at quantifying mammal local exposure to climate change across species' ranges. We identified areas in the Brazilian Amazon where mammals will be critically exposed to non-analogue climates in the future with different variables predicted by 15 global circulation climate forecasts. We also built a null model to assess the effectiveness of the Amazon protected areas in buffering the effects of climate change on mammals, using an innovative and more realistic approach. We found that 85% of species are likely to be exposed to non-analogue climatic conditions in more than 80% of their ranges by 2070. That percentage is even higher for endemic mammals; almost all endemic species are predicted to be exposed in more than 80% of their range. Exposure patterns also varied with different climatic variables and seem to be geographically structured. Western and northern Amazon species are more likely to experience temperature anomalies while northeastern species will be more affected by rainfall abnormality. We also observed an increase in the number of critically-exposed species from 2050 to 2070. Overall, our results indicate that mammals might face high exposure to climate change and that protected areas will probably not be efficient enough to avert those impacts.

  10. Assessing Mammal Exposure to Climate Change in the Brazilian Amazon

    PubMed Central

    Ribeiro, Bruno R.; Sales, Lilian P.; De Marco, Paulo; Loyola, Rafael

    2016-01-01

    Human-induced climate change is considered a conspicuous threat to biodiversity in the 21st century. Species’ response to climate change depends on their exposition, sensitivity and ability to adapt to novel climates. Exposure to climate change is however uneven within species’ range, so that some populations may be more at risk than others. Identifying the regions most exposed to climate change is therefore a first and pivotal step on determining species’ vulnerability across their geographic ranges. Here, we aimed at quantifying mammal local exposure to climate change across species’ ranges. We identified areas in the Brazilian Amazon where mammals will be critically exposed to non-analogue climates in the future with different variables predicted by 15 global circulation climate forecasts. We also built a null model to assess the effectiveness of the Amazon protected areas in buffering the effects of climate change on mammals, using an innovative and more realistic approach. We found that 85% of species are likely to be exposed to non-analogue climatic conditions in more than 80% of their ranges by 2070. That percentage is even higher for endemic mammals; almost all endemic species are predicted to be exposed in more than 80% of their range. Exposure patterns also varied with different climatic variables and seem to be geographically structured. Western and northern Amazon species are more likely to experience temperature anomalies while northeastern species will be more affected by rainfall abnormality. We also observed an increase in the number of critically-exposed species from 2050 to 2070. Overall, our results indicate that mammals might face high exposure to climate change and that protected areas will probably not be efficient enough to avert those impacts. PMID:27829036

  11. Monitor for detecting and assessing exposure to airborne nanoparticles

    NASA Astrophysics Data System (ADS)

    Marra, Johan; Voetz, Matthias; Kiesling, Heinz-Jürgen

    2010-01-01

    An important safety aspect of the workplace environment concerns the severity of its air pollution with nanoparticles (NP; <100 nm) and ultrafine particles (UFP; <300 nm). Depending on their size and chemical nature, exposure to these particles through inhalation can be hazardous because of their intrinsic ability to deposit in the deep lung regions and the possibility to subsequently pass into the blood stream. Recommended safety measures in the nanomaterials industry are pragmatic, aiming at exposure minimization in general, and advocating continuous control by monitoring both the workplace air pollution level and the personal exposure to airborne NPs. This article describes the design and operation of the Aerasense NP monitor that enables intelligence gathering in particular with respect to airborne particles in the 10-300 nm size range. The NP monitor provides real time information about their number concentration, average size, and surface areas per unit volume of inhaled air that deposit in the various compartments of the respiratory tract. The monitor's functionality relies on electrical charging of airborne particles and subsequent measurements of the total particle charge concentration under various conditions. Information obtained with the NP monitor in a typical workplace environment has been compared with simultaneously recorded data from a Scanning Mobility Particle Sizer (SMPS) capable of measuring the particle size distribution in the 11-1086 nm size range. When the toxicological properties of the engineered and/or released particles in the workplace are known, personal exposure monitoring allows a risk assessment to be made for a worker during each workday, when the workplace-produced particles can be distinguished from other (ambient) particles.

  12. A Cost-Benefit and Accurate Method for Assessing Microalbuminuria: Single versus Frequent Urine Analysis.

    PubMed

    Hemmati, Roholla; Gharipour, Mojgan; Khosravi, Alireza; Jozan, Mahnaz

    2013-01-01

    Background. The purpose of this study was to answer the question whether a single testing for microalbuminuria results in a reliable conclusion leading costs saving. Methods. This current cross-sectional study included a total of 126 consecutive persons. Microalbuminuria was assessed by collection of two fasting random urine specimens on arrival to the clinic as well as one week later in the morning. Results. In overall, 17 out of 126 participants suffered from microalbuminuria that, among them, 12 subjects were also diagnosed as microalbuminuria once assessing this factor with a sensitivity of 70.6%, a specificity of 100%, a PPV of 100%, a NPV of 95.6%, and an accuracy of 96.0%. The measured sensitivity, specificity, PVV, NPV, and accuracy in hypertensive patients were 73.3%, 100%, 100%, 94.8%, and 95.5%, respectively. Also, these rates in nonhypertensive groups were 50.0%, 100%, 100%, 97.3%, and 97.4%, respectively. According to the ROC curve analysis, a single measurement of UACR had a high value for discriminating defected from normal renal function state (c = 0.989). Urinary albumin concentration in a single measurement had also high discriminative value for diagnosis of damaged kidney (c = 0.995). Conclusion. The single testing of both UACR and urine albumin level rather frequent testing leads to high diagnostic sensitivity, specificity, and accuracy as well as high predictive values in total population and also in hypertensive subgroups.

  13. Assessing Climate Change Impacts on Wildfire Exposure in Mediterranean Areas.

    PubMed

    Lozano, Olga M; Salis, Michele; Ager, Alan A; Arca, Bachisio; Alcasena, Fermin J; Monteiro, Antonio T; Finney, Mark A; Del Giudice, Liliana; Scoccimarro, Enrico; Spano, Donatella

    2016-12-20

    We used simulation modeling to assess potential climate change impacts on wildfire exposure in Italy and Corsica (France). Weather data were obtained from a regional climate model for the period 1981-2070 using the IPCC A1B emissions scenario. Wildfire simulations were performed with the minimum travel time fire spread algorithm using predicted fuel moisture, wind speed, and wind direction to simulate expected changes in weather for three climatic periods (1981-2010, 2011-2040, and 2041-2070). Overall, the wildfire simulations showed very slight changes in flame length, while other outputs such as burn probability and fire size increased significantly in the second future period (2041-2070), especially in the southern portion of the study area. The projected changes fuel moisture could result in a lengthening of the fire season for the entire study area. This work represents the first application in Europe of a methodology based on high resolution (250 m) landscape wildfire modeling to assess potential impacts of climate changes on wildfire exposure at a national scale. The findings can provide information and support in wildfire management planning and fire risk mitigation activities.

  14. Assessing potential exposure of birds to pesticide-treated seeds.

    PubMed

    Prosser, Phil; Hart, A D M

    2005-10-01

    Seed treatments are widely used for crop protection and present a particular risk to granivorous birds. UK risk assessment for seed treatments has tended to focus on highly granivorous species; however, under some conditions, non-granivorous birds will take seeds. Better data is needed on which species eat seeds for which pesticide treatments are used. To identify which species will take and eat a range of crop seeds in common usage in the UK, birds visiting bait stations at which untreated seed was presented were video recorded. Information was also obtained on how much seed is taken by individual birds. The seeds tested were wheat, barley, maize, oilseed rape, grass, peas and pelleted sugar beet. For many of the species observed at the bait stations, the amounts of seed consumed during single visits were sufficient to pose a potential risk (toxicity-exposure ratio < 10) if the seed had been treated with one of the more acutely toxic seed treatments. Previous studies have shown that de-husking of seeds can substantially reduce birds' exposure. This paper provides information on which of the species recorded de-husked which seeds, in field conditions. The use of these data in pesticide risk assessment is considered.

  15. Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants.

    PubMed Central

    Möller, L; Schuetzle, D; Autrup, H

    1994-01-01

    This paper presents key conclusions and future research needs from a Workshop on the Risk Assessment of Urban Air, Emissions, Exposure, Risk Identification, and Quantification, which was held in Stockholm during June 1992 by 41 participants from 13 countries. Research is recommended in the areas of identification and quantification of toxics in source emissions and ambient air, atmospheric transport and chemistry, exposure level assessment, the development of improved in vitro bioassays, biomarker development, the development of more accurate epidemiological methodologies, and risk quantification techniques. Studies are described that will be necessary to assess and reduce the level of uncertainties associated with each step of the risk assessment process. International collaborative research efforts between industry and government organizations are recommended as the most effective way to carry out this research. PMID:7529703

  16. Assessing population exposure for landslide risk analysis using dasymetric cartography

    NASA Astrophysics Data System (ADS)

    Garcia, Ricardo A. C.; Oliveira, Sérgio C.; Zêzere, José L.

    2016-12-01

    Assessing the number and locations of exposed people is a crucial step in landslide risk management and emergency planning. The available population statistical data frequently have insufficient detail for an accurate assessment of potentially exposed people to hazardous events, mainly when they occur at the local scale, such as with landslides. The present study aims to apply dasymetric cartography to improving population spatial resolution and to assess the potentially exposed population. An additional objective is to compare the results with those obtained with a more common approach that uses, as spatial units, basic census units, which are the best spatial data disaggregation and detailed information available for regional studies in Portugal. Considering the Portuguese census data and a layer of residential building footprint, which was used as ancillary information, the number of exposed inhabitants differs significantly according to the approach used. When the census unit approach is used, considering the three highest landslide susceptible classes, the number of exposed inhabitants is in general overestimated. Despite the associated uncertainties of a general cost-benefit analysis, the presented methodology seems to be a reliable approach for gaining a first approximation of a more detailed estimation of exposed people. The approach based on dasymetric cartography allows the spatial resolution of population over large areas to be increased and enables the use of detailed landslide susceptibility maps, which are valuable for improving the exposed population assessment.

  17. Quick, Accurate, Smart: 3D Computer Vision Technology Helps Assessing Confined Animals' Behaviour.

    PubMed

    Barnard, Shanis; Calderara, Simone; Pistocchi, Simone; Cucchiara, Rita; Podaliri-Vulpiani, Michele; Messori, Stefano; Ferri, Nicola

    2016-01-01

    Mankind directly controls the environment and lifestyles of several domestic species for purposes ranging from production and research to conservation and companionship. These environments and lifestyles may not offer these animals the best quality of life. Behaviour is a direct reflection of how the animal is coping with its environment. Behavioural indicators are thus among the preferred parameters to assess welfare. However, behavioural recording (usually from video) can be very time consuming and the accuracy and reliability of the output rely on the experience and background of the observers. The outburst of new video technology and computer image processing gives the basis for promising solutions. In this pilot study, we present a new prototype software able to automatically infer the behaviour of dogs housed in kennels from 3D visual data and through structured machine learning frameworks. Depth information acquired through 3D features, body part detection and training are the key elements that allow the machine to recognise postures, trajectories inside the kennel and patterns of movement that can be later labelled at convenience. The main innovation of the software is its ability to automatically cluster frequently observed temporal patterns of movement without any pre-set ethogram. Conversely, when common patterns are defined through training, a deviation from normal behaviour in time or between individuals could be assessed. The software accuracy in correctly detecting the dogs' behaviour was checked through a validation process. An automatic behaviour recognition system, independent from human subjectivity, could add scientific knowledge on animals' quality of life in confinement as well as saving time and resources. This 3D framework was designed to be invariant to the dog's shape and size and could be extended to farm, laboratory and zoo quadrupeds in artificial housing. The computer vision technique applied to this software is innovative in non

  18. Quick, Accurate, Smart: 3D Computer Vision Technology Helps Assessing Confined Animals’ Behaviour

    PubMed Central

    Calderara, Simone; Pistocchi, Simone; Cucchiara, Rita; Podaliri-Vulpiani, Michele; Messori, Stefano; Ferri, Nicola

    2016-01-01

    Mankind directly controls the environment and lifestyles of several domestic species for purposes ranging from production and research to conservation and companionship. These environments and lifestyles may not offer these animals the best quality of life. Behaviour is a direct reflection of how the animal is coping with its environment. Behavioural indicators are thus among the preferred parameters to assess welfare. However, behavioural recording (usually from video) can be very time consuming and the accuracy and reliability of the output rely on the experience and background of the observers. The outburst of new video technology and computer image processing gives the basis for promising solutions. In this pilot study, we present a new prototype software able to automatically infer the behaviour of dogs housed in kennels from 3D visual data and through structured machine learning frameworks. Depth information acquired through 3D features, body part detection and training are the key elements that allow the machine to recognise postures, trajectories inside the kennel and patterns of movement that can be later labelled at convenience. The main innovation of the software is its ability to automatically cluster frequently observed temporal patterns of movement without any pre-set ethogram. Conversely, when common patterns are defined through training, a deviation from normal behaviour in time or between individuals could be assessed. The software accuracy in correctly detecting the dogs’ behaviour was checked through a validation process. An automatic behaviour recognition system, independent from human subjectivity, could add scientific knowledge on animals’ quality of life in confinement as well as saving time and resources. This 3D framework was designed to be invariant to the dog’s shape and size and could be extended to farm, laboratory and zoo quadrupeds in artificial housing. The computer vision technique applied to this software is innovative in non

  19. Assessment of multiple frequency ELF electric and magnetic field exposure

    NASA Astrophysics Data System (ADS)

    Leitgeb, N.

    2008-01-01

    Electromagnetic fields both in daily life and at workplaces exhibit increasingly complex frequency spectra. Present spectral assessment rules proved to be too conservative for health risk assessment. This is because they are based on the assumption that cells would react like linear systems in terms of responding to a sum of frequencies by a sum of independent responses to each individual frequency. Based on numerical investigations with the Hodgkin-Huxley and the Frankenhaeuser-Huxley nerve cell models, it could be shown that accounting for the nonlinear behaviour of cellular excitation processes avoids considerable overestimation of simultaneous exposures to multiple frequency ELF electric and magnetic fields. Besides this, it could be shown that the role of phase relationships is less important than that assumed so far. The present assessment rules lead to non-compliances of marketed electric appliances. For general application, a nonlinear biology-based assessment (NBBA) rule has been proposed, validated and proven advantageous compared with ICNIRP's rule. While staying conservative it avoids unnecessary overestimation and demonstrates compliance even in cases of suspected non-conformities. It is up to responsible bodies to decide upon the adoption of this proposal and the potential need for implementing additional or reducing the already incorporated safety factors.

  20. Assessment of multiple frequency ELF electric and magnetic field exposure.

    PubMed

    Leitgeb, N

    2008-01-21

    Electromagnetic fields both in daily life and at workplaces exhibit increasingly complex frequency spectra. Present spectral assessment rules proved to be too conservative for health risk assessment. This is because they are based on the assumption that cells would react like linear systems in terms of responding to a sum of frequencies by a sum of independent responses to each individual frequency. Based on numerical investigations with the Hodgkin-Huxley and the Frankenhaeuser-Huxley nerve cell models, it could be shown that accounting for the nonlinear behaviour of cellular excitation processes avoids considerable overestimation of simultaneous exposures to multiple frequency ELF electric and magnetic fields. Besides this, it could be shown that the role of phase relationships is less important than that assumed so far. The present assessment rules lead to non-compliances of marketed electric appliances. For general application, a nonlinear biology-based assessment (NBBA) rule has been proposed, validated and proven advantageous compared with ICNIRP's rule. While staying conservative it avoids unnecessary overestimation and demonstrates compliance even in cases of suspected non-conformities. It is up to responsible bodies to decide upon the adoption of this proposal and the potential need for implementing additional or reducing the already incorporated safety factors.

  1. Developing and evaluating distributions for probabilistic human exposure assessments

    SciTech Connect

    Maddalena, Randy L.; McKone, Thomas E.

    2002-08-01

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

  2. Human tissue monitoring and specimen banking: opportunities for exposure assessment, risk assessment, and epidemiologic research.

    PubMed Central

    Lee, L W; Griffith, J; Zenick, H; Hulka, B S

    1995-01-01

    A symposium on Human Tissue Monitoring and Specimen Banking: Opportunities for Exposure Assessment, Risk Assessment, and Epidemiologic Research was held from 30 March to 1 April 1993 in Research Triangle Park, North Carolina. There were 117 registered participants from 18 states and 5 foreign countries. The first 2 days featured 21 invited speakers from the U.S. Environmental Protection Agency, the Centers for Disease Control and Prevention, the National Institute of Environmental Health Sciences, various other government agencies, and universities in the United States, Canada, Germany, and Norway. The speakers provided a state-of-the-art overview of human exposure assessment techniques (especially applications of biological markers) and their relevance to human tissue specimen banking. Issues relevant to large-scale specimen banking were discussed, including program design, sample design, data collection, tissue collection, and ethical ramifications. The final group of presentations concerned practical experiences of major specimen banking and human tissue monitoring programs in the United States and Europe. The symposium addressed the utility and research opportunities afforded by specimen banking programs for future research needs in the areas of human exposure assessment, risk assessment, and environmental epidemiology. The third day of the symposium consisted of a small workshop convened to discuss and develop recommendations to the U.S. Environmental Protection Agency regarding applications and utility of large-scale specimen banking, biological monitoring, and biological markers for risk assessment activities. PMID:7635108

  3. Occupational dermal exposure to nanoparticles and nano-enabled products: Part 2, exploration of exposure processes and methods of assessment.

    PubMed

    Brouwer, Derk H; Spaan, Suzanne; Roff, Martin; Sleeuwenhoek, Anne; Tuinman, Ilse; Goede, Henk; van Duuren-Stuurman, Birgit; Filon, Francesca Larese; Bello, Dhimiter; Cherrie, John W

    2016-08-01

    Over the past decade, the primary focus of nanotoxicology and nanoenvironmental health and safety efforts has been largely on inhalation exposure to engineered nanomaterials, at the production stage, and much less on considering risks along the life cycle of nano-enabled products. Dermal exposure to nanomaterials and its health impact has been studied to a much lesser extent, and mostly in the context of intentional exposure to nano-enabled products such as in nanomedicine, cosmetics and personal care products. How concerning is dermal exposure to such nanoparticles in the context of occupational exposures? When and how should we measure it? In the first of a series of two papers (Larese Filon et al., 2016), we focused our attention on identifying conditions or situations, i.e. a combination of nanoparticle physico-chemical properties, skin barrier integrity, and occupations with high prevalence of skin disease, which deserve further investigation. This second paper focuses on the broad question of dermal exposure assessment to nanoparticles and attempts to give an overview of the mechanisms of occupational dermal exposure to nanoparticles and nano-enabled products and explores feasibility and adequacy of various methods of quantifying dermal exposure to NOAA. We provide here a conceptual framework for screening, prioritization, and assessment of dermal exposure to NOAA in occupational settings, and integrate it into a proposed framework for risk assessment.

  4. HEALTH EFFECTS OF CHRONIC EXPOSURE TO ARSENIC VIA DRINKING WATER IN INNER MONGOLIA: I. BIOMARKERS FOR ASSESSING EXPOSURE AND EFFECTS

    EPA Science Inventory

    Health Effects of Chronic Exposure to Arsenic via Drinking Water in Inner Mongolia: I. Biomarkers for Assessing Exposure and Effects

    Judy L. Mumford, Ph.D., Mike Schmitt, M.S.P.H., Richard K. Kwok, M.S.P.H., Rebecca Calderon, Ph.D., National Health and Environmental Effect...

  5. Exposure Assessment Tools by Approaches - Direct Measurement (Point-of-Contact Measurement)

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases, mode

  6. A PROPOSED FRAMEWORK FOR ASSESSING RISK FROM LESS-THAN-LIFETIME EXPOSURES TO CARCINOGENS

    EPA Science Inventory

    Quantitative cancer risk assessment methods have been developed for daily, lifetime human exposures, but not for exposures that are less than lifetime. Few examples for less-than-Iifetime exposures exist in the published literature. To move cancer risk assessment beyond reliance ...

  7. Exposure Assessment Tools by Tiers and Types - Screening-Level and Refined

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  8. Exposure Assessment Tools by Lifestages and Populations - Highly Exposed or Other Susceptible Population Groups

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

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

    PubMed

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

    2015-11-01

    In the recent years hair has been increasingly used as alternative matrix in human biomonitoring (HBM) of environmental pollutants. Sampling advantages and time integration of exposure assessment seems the most attractive features of hair matrix. In the current study, a novel miniaturized method was developed and validated for measuring 15 perfluoroalkyl substances (PFAS), including perfluoro n-butanoic acid (PFBA), perfluoro n-pentanoic acid (PFPeA), perfluoro n-hexanoic acid (PFHxA), perfluoro n-heptanoic acid (PFHpA), perfluor n-octanoic acid (PFOA), perfluoro n-nonanoic acid (PFNA), perfluoro tetradecanoic acid (PFTeDA), perfluorobutane sulfonic acid (PFBS), perfluoro pentane sulfonic acid (PFPeS), perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), perfluorooctane sulfonic acid (PFOS), perfluorononane sulfonic acid (PFNS), perfluorodecane sulfonic acid (PFDS) and perfluorododecane sulfonic acid (PFDoS) in human hair by liquid chromatography tandem mass spectrometry (LC-MS/MS). After extraction using ethyl acetate, dispersive ENVI-Carb was used for clean-up. Good intra- and inter-day precision for low (LQ 5 ng/g hair) and high spike (HQ 15n g/g) levels were achieved (in general RSD <10%). The accuracy was assessed using recoveries (%), which ranged between 68-118% (LQ) and 70-121% (HQ). The instrumental limit of detection (LODi) and limit of quantification (LOQi) were between 1-4 pg/g hair and 3-13 pg/g hair, respectively. The method limit of quantification (LOQm) ranged between 6 and 301 pg/g hair. The PFAS levels were measured in 30 human hair samples indicating that the levels are low (14-1534 pg/g hair). Some PFAS were not present in any hair sample (e.g. PFHpA, PFTeDA, PFNA, PFPeS, PFHpS, PFOS and PFNS), while other PFAS were frequently detected (PFBA, PFPeA, PFHxA, PFOA, PFBS, PFHxS, PFOS, PFDS and PFDoS) in human hair. Although levels in general were low, there is evidence of higher human exposure to some analytes, such as PFBA

  10. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling.

    PubMed

    Aerts, Sam; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-10-01

    In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information-inside hotspots or in search of them-based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km2. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96.

  11. KREAM: Korean Radiation Exposure Assessment Model for Aviation Route Dose

    NASA Astrophysics Data System (ADS)

    Hwang, J.; Dokgo, K.; Choi, E. J.; Kim, K. C.; Kim, H. P.; Cho, K. S. F.

    2014-12-01

    Since Korean Air has begun to use the polar route from Seoul/ICN airport to New York/JFK airport on August 2006, there are explosive needs for the estimation and prediction against cosmic radiation exposure for Korean aircrew and passengers in South Korea from public. To keep pace with those needs of public, Korean government made the law on safety standards and managements of cosmic radiation for the flight attendants and the pilots in 2013. And we have begun to develop our own Korean Radiation Exposure Assessment Model (KREAM) for aviation route dose since last year funded by Korea Meteorological Administration (KMA). GEANT4 model and NRLMSIS 00 model are used for calculation of the energetic particles' transport in the atmosphere and for obtaining the background atmospheric neutral densities depending on altitude. For prediction the radiation exposure in many routes depending on the various space weather effects, we constructed a database from pre-arranged simulations using all possible combinations of R, S, and G, which are the space weather effect scales provided by the National Oceanic and Atmospheric Administration (NOAA). To get the solar energetic particles' spectrum at the 100 km altitude which we set as a top of the atmospheric layers in the KREAM, we use ACE and GOES satellites' proton flux observations. We compare the results between KREAM and the other cosmic radiation estimation programs such as CARI-6M which is provided by the Federal Aviation Agency (FAA). We also validate KREAM's results by comparison with the measurement from Liulin-6K LET spectrometer onboard Korean commercial flights and Korean Air Force reconnaissance flights.

  12. Assessment of human exposure to chemicals from Superfund sites.

    PubMed Central

    Kamrin, M A; Fischer, L J; Suk, W A; Fouts, J R; Pellizzari, E; Thornton, K

    1994-01-01

    Assessing human exposure to chemicals from Superfund sites requires knowledge of basic physical, chemical, and biological processes occurring in the environment and specific information about the local environment and population in the vicinity of sites of interest. Although progress is being made in both areas, there is still a tremendous amount to be done. Participants at this meeting have identified several of the areas in need of greater understanding, and they are listed below. Movement of dissolved and volatile organics, especially NAPLs, in the subsurface environment. This includes study of the partitioning of compounds between NAPLs, air, water, and soil. Partitioning of volatilized chemicals between gaseous and aerosol components of the atmosphere. This includes understanding how these components influence both wet and dry deposition. Long-term movement from sediments into biota and how these affect chronic toxicity to sediment biota. Broad validation of PBPK models describing partitioning of compounds from sediment and water into fish. Reactions of chemicals sorbed to atmospheric particles. This includes application of laboratory models to real and varied atmospheric conditions. Interactions between biotic and abiotic transformations in soil and sediment. Applicability of physiological pharmacokinetic models developed in laboratory studies of experimental animals and clinical investigations of humans to environmental chemicals, concentrations, and routes of exposure in humans. Use of human and wildlife behavioral and biomonitoring information to estimate exposure. This includes better understanding of human variability and the applicability of information gathered from particular wildlife species. To successfully address these gaps in our knowledge, much more analytical data must be collected.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8187712

  13. Evidence that bisphenol A (BPA) can be accurately measured without contamination in human serum and urine, and that BPA causes numerous hazards from multiple routes of exposure.

    PubMed

    vom Saal, Frederick S; Welshons, Wade V

    2014-12-01

    There is extensive evidence that bisphenol A (BPA) is related to a wide range of adverse health effects based on both human and experimental animal studies. However, a number of regulatory agencies have ignored all hazard findings. Reports of high levels of unconjugated (bioactive) serum BPA in dozens of human biomonitoring studies have also been rejected based on the prediction that the findings are due to assay contamination and that virtually all ingested BPA is rapidly converted to inactive metabolites. NIH and industry-sponsored round robin studies have demonstrated that serum BPA can be accurately assayed without contamination, while the FDA lab has acknowledged uncontrolled assay contamination. In reviewing the published BPA biomonitoring data, we find that assay contamination is, in fact, well controlled in most labs, and cannot be used as the basis for discounting evidence that significant and virtually continuous exposure to BPA must be occurring from multiple sources.

  14. Evidence that bisphenol A (BPA) can be accurately measured without contamination in human serum and urine, and that BPA causes numerous hazards from multiple routes of exposure

    PubMed Central

    vom Saal, Frederick S.; Welshons, Wade V.

    2016-01-01

    There is extensive evidence that bisphenol A (BPA) is related to a wide range of adverse health effects based on both human and experimental animal studies. However, a number of regulatory agencies have ignored all hazard findings. Reports of high levels of unconjugated (bioactive) serum BPA in dozens of human biomonitoring studies have also been rejected based on the prediction that the findings are due to assay contamination and that virtually all ingested BPA is rapidly converted to inactive metabolites. NIH and industry-sponsored round robin studies have demonstrated that serum BPA can be accurately assayed without contamination, while the FDA lab has acknowledged uncontrolled assay contamination. In reviewing the published BPA biomonitoring data, we find that assay contamination is, in fact, well controlled in most labs, and cannot be used as the basis for discounting evidence that significant and virtually continuous exposure to BPA must be occurring from multiple sources. PMID:25304273

  15. Sensors on the humerus are not necessary for an accurate assessment of humeral kinematics in constrained movements.

    PubMed

    Lin, Yin-Liang; Karduna, Andrew R

    2013-08-01

    The measurement of humeral kinematics with a sensor on the humerus is susceptible to large errors due to skin motion artifacts. An alternative approach is to use data from a forearm sensor, combined with data from either a scapular or thoracic sensor. We used three tasks to assess the errors of these approaches: humeral elevation, elbow flexion and humeral internal rotation. Compared with the humeral method, the forearm methods (using either a scapular or thoracic sensor) demonstrated significantly smaller root mean square errors in humeral elevation and humeral internal rotation tasks. Although the errors of the forearm methods were significantly larger than those of the humeral method during elbow flexion, the errors of the forearm methods still were below 3°. Therefore, these forearm methods may be able to accurately measure humeral motion. In addition, since no difference was found between the forearm methods using the scapular or thoracic sensor, it may be possible to accurately assess both shoulder and elbow kinematics with only two sensors: one on the forearm and one on the scapula.

  16. Duplicate portion sampling combined with spectrophotometric analysis affords the most accurate results when assessing daily dietary phosphorus intake.

    PubMed

    Navarro-Alarcon, Miguel; Zambrano, Esmeralda; Moreno-Montoro, Miriam; Agil, Ahmad; Olalla, Manuel

    2012-08-01

    The assessment of daily dietary phosphorus (P) intake is a major concern in human nutrition because of its relationship with Ca and Mg metabolism and osteoporosis. Within this context, we hypothesized that several of the methods available for the assessment of daily dietary intake of P are equally accurate and reliable, although few studies have been conducted to confirm this. The aim of this study then was to evaluate daily dietary P intake, which we did by 3 methods: duplicate portion sampling of 108 hospital meals, combined either with spectrophotometric analysis or the use of food composition tables, and 24-hour dietary recall for 3 consecutive days plus the use of food composition tables. The mean P daily dietary intakes found were 1106 ± 221, 1480 ± 221, and 1515 ± 223 mg/d, respectively. Daily dietary intake of P determined by spectrophotometric analysis was significantly lower (P < .001) and closer to dietary reference intakes for adolescents aged from 14 to 18 years (88.5%) and adult subjects (158.1%) compared with the other 2 methods. Duplicate portion sampling with P analysis takes into account the influence of technological and cooking processes on the P content of foods and meals and therefore afforded the most accurate and reliable P daily dietary intakes. The use of referred food composition tables overestimated daily dietary P intake. No adverse effects in relation to P nutrition (deficiencies or toxic effects) were encountered.

  17. Visual Risk Assessment of Space Radiation Exposure for Future Space Exploration Missions

    NASA Technical Reports Server (NTRS)

    Hussein, Hesham F.; Kim, Myung-Hee; Cucinotta, Francis A.

    2006-01-01

    Protecting astronauts from space radiation exposure during an interplanetary mission is an important challenge for mission design and operations. If sufficient protection is not provided near solar maximum, the risk can be significant due to exposure to sporadic solar particle events (SPEs) as well as to the continuous galactic cosmic radiation (GCR). Polyethylene shielded "storm shelters" inside spacecraft have been shown to limit total exposure from a large SPE to a permissible level, preventing acute risks and providing a potential approach to fulfill the ALARA (as low as reasonably achievable) requirement. For accurate predictions of radiation dose to astronauts involved in future space exploration missions, detailed variations of radiation shielding properties are required. Radiation fluences and doses vary considerably across both the spacecraft geometry and the body-shielding distribution. A model using a modern CAD tool ProE(TradeMark), which is the leading engineering design platform at NASA, has been developed to account for these local variations in the radiation distribution. Visual assessment of radiation distribution at different points inside a spacecraft module and in the human body for a given radiation environment are described. Results will ultimately guide in developing requirements for maximal protection for astronauts from space radiation.

  18. Assessment of planctomycetes cell viability after pollutants exposure.

    PubMed

    Flores, Carlos; Catita, José A M; Lage, Olga Maria

    2014-08-01

    In this study, the growth of six different planctomycetes, a particular ubiquitous bacterial phylum, was assessed after exposure to pollutants. In addition and for comparative purposes, Pseudomonas putida, Escherichia coli and Vibrio anguillarum were tested. Each microorganism was exposed to several concentrations of 21 different pollutants. After exposure, bacteria were cultivated using the drop plate method. In general, the strains exhibited a great variation of sensitivity to pollutants in the order: V. anguillarum > planctomycetes > P. putida > E. coli. E. coli showed resistance to all pollutants tested, with the exception of phenol and sodium azide. Copper, Ridomil® (fungicide), hydrazine and phenol were the most toxic pollutants. Planctomycetes were resistant to extremely high concentrations of nitrate, nitrite and ammonium but they were the only bacteria sensitive to Previcur N® (fungicide). Sodium azide affected the growth on plates of E. coli, P. putida and V. anguillarum, but not of planctomycetes. However, this compound affected planctomycetes cell respiration but with less impact than in the aforementioned bacteria. Our results provide evidence for a diverse response of bacteria towards pollutants, which may influence the structuring of microbial communities in ecosystems under stress, and provide new insights on the ecophysiology of planctomycetes.

  19. Personalized Cancer Risk Assessments for Space Radiation Exposures

    PubMed Central

    Locke, Paul A.; Weil, Michael M.

    2016-01-01

    Individuals differ in their susceptibility to radiogenic cancers, and there is evidence that this inter-individual susceptibility extends to HZE ion-induced carcinogenesis. Three components of individual risk: sex, age at exposure, and prior tobacco use, are already incorporated into the NASA cancer risk model used to determine safe days in space for US astronauts. Here, we examine other risk factors that could potentially be included in risk calculations. These include personal and family medical history, the presence of pre-malignant cells that could undergo malignant transformation as a consequence of radiation exposure, the results from phenotypic assays of radiosensitivity, heritable genetic polymorphisms associated with radiosensitivity, and postflight monitoring. Inclusion of these additional risk or risk reduction factors has the potential to personalize risk estimates for individual astronauts and could influence the determination of safe days in space. We consider how this type of assessment could be used and explore how the provisions of the federal Genetic Information Non-discrimination Act could impact the collection, dissemination and use of this information by NASA. PMID:26942127

  20. Measures for Assessing Subjective Effects of Potential Reduced Exposure Products

    PubMed Central

    Hanson, Karen; O’Connor, Richard; Hatsukami, Dorothy

    2009-01-01

    Potential reduced exposure products (PREPs) may reduce toxicant exposure and thereby may possibly reduce health risks associated with conventional tobacco use. However, lessened health risk to the individual or harm to the population through use of PREPs is unknown. Research is being conducted to evaluate the possible health effects associated with PREP use. As part of this evaluation, it is critical to provide sound measures of subjective responses to PREPs to determine the use and the abuse potential of a product, that is the likelihood that this product will lead to addiction. The goal of this paper is to conduct a systematic review of scales that have been used to measure the subjective responses to PREPs and examine their characteristics. In this paper, scales are identified and the items on the scales are described. Scales are also examined to determine whether they are sensitive in testing PREPs. Furthermore, scales to assess PREPs are recommended to investigators. Where no scales exist, items that may be critical for the development and validation of new scales are identified. PMID:19959674

  1. Assessment of soil lead exposure in children in Shenyang, China.

    PubMed

    Ren, H M; Wang, J D; Zhang, X L

    2006-11-01

    Soil lead pollution is serious in Shenyang, China. The paper brings together the soil work, the bioaccessibility, and the blood lead data to assess the soil lead exposure in children in Shenyang, China. Approximately 15.25% of the samples were above China Environment Protection Agency guideline concentration for soil Pb to protect human from health risk (350 mgkg(-1)). Pb concentrations varied among use scenarios. The main lead contamination sources are industry emission and automobile exhaust. Bioaccessibility also varied among use scenarios. Children, who ingested soil from industrial area, public parks, kindergarten playground, and commercial area, are more susceptible to soil lead toxicity. The industrial area soil samples presented higher bioaccessibility compared to the other use scenario soil samples contaminated by automobile exhaust. The result also suggested a most significant linear relationship between the level of Pb contamination and the amount of Pb mobilized from soil into ingestion juice. Soil pH seemed to have insignificant influence on bioaccessibility in the present study. Bioaccessibility was mainly controlled by other factors that are not investigated in this study. A linear relationship between children blood lead and soil intestinal bioaccessibility was present in the study. Children who are 4-5 years old are more likely to demonstrate the significant relationship between soil lead bioaccessibility and blood lead as their behaviors place them at greatest risk of soil lead toxicity, and their blood lead levels are more likely to represent recent exposure.

  2. A risk assessment framework for assessing metallic nanomaterials of environmental concern: aquatic exposure and behavior.

    PubMed

    O'Brien, Niall Joseph; Cummins, Enda J

    2011-05-01

    Nanomaterials are finding application in many different environmentally relevant products and processes due to enhanced catalytic, antimicrobial, and oxidative properties of materials at this scale. As the market share of nano-functionalized products increases, so too does the potential for environmental exposure and contamination. This study presents some exposure ranking methods that consider potential metallic nanomaterial surface water exposure and fate, due to nano-functionalized products, through a number of exposure pathways. These methods take into account the limited and disparate data currently available for metallic nanomaterials and apply variability and uncertainty principles, together with qualitative risk assessment principles, to develop a scientific ranking. Three exposure scenarios with three different nanomaterials were considered to demonstrate these assessment methods: photo-catalytic exterior paint (nano-scale TiO₂), antimicrobial food packaging (nano-scale Ag), and particulate-reducing diesel fuel additives (nano-scale CeO₂). Data and hypotheses from literature relating to metallic nanomaterial aquatic behavior (including the behavior of materials that may relate to nanomaterials in aquatic environments, e.g., metals, pesticides, surfactants) were used together with commercial nanomaterial characteristics and Irish natural aquatic environment characteristics to rank the potential concentrations, transport, and persistence behaviors within subjective categories. These methods, and the applied scenarios, reveal where data critical to estimating exposure and risk are lacking. As research into the behavior of metallic nanomaterials in different environments emerges, the influence of material and environmental characteristics on nanomaterial behavior within these exposure- and risk-ranking methods may be redefined on a quantitative basis.

  3. Assessment of carcinogenic risk from personal exposure to benzo(a)pyrene in the Total Human Environmental Exposure Study (THEES)

    SciTech Connect

    Butler, J.P.; Post, G.B.; Lioy, P.J.; Waldman, J.M.; Greenberg, A. )

    1993-07-01

    The Total Human Environmental Exposure Study (THEES) was an investigation of multimedia exposure to the ubiquitous environmental carcinogen, benzo(a)pyrene (BaP). The three-phase study was conducted in Phillipsburg, New Jersey and involved the participation of 14-15 individuals (8-10 homes) during each 14-day monitoring period. Microenvironmental sampling of air, food, water and soil indicated that environmental exposure to BaP was primarily through air and food. Exposure and risk estimates were, therefore, based on the results of personal monitoring of breathing zone air and prepared food samples. Based on a comparison of the range and magnitude of inhalation and dietary BaP exposures, food ingestion was clearly the predominant exposure to pathway. The relative contributions of other potential sources of community exposure to BaP (e.g., soil and drinking water ingestion) were also assessed. The excess cancer risk estimates for food ingestion were consistently greater than those for personal air, reflecting both the predominantly higher BaP exposures through the diet and the higher carcinogenic potency value for oral exposure. Overall, the total lifetime risk from personal exposure to BaP for nonsmokers in the community was estimated at 10(-5). In identifying risk reduction options, it is important to account for the observation that personal activities, lifestyle, and diet strongly influenced individual exposures to BaP.

  4. {sup 125}I Measurements for Occupational Exposure Assessment

    SciTech Connect

    Silva, L.; Pinhao, N. R.

    2008-08-14

    Whenever there is a risk of occupational exposure to dispersible radioactive material, it is necessary to have a monitoring program to assess the effective dose arising from the intake of radionuclides by workers. In this paper we present our experience in bioassay measurements of {sup 125}I in urine samples of workers using high resolution gamma spectrometry. For a 24-hour excretion period, we found activity values of the order of one Bq and estimated the committed effective doses to be less than one {mu}Sv. Although very small, these values led to a re-evaluation and improvement of the laboratory safety conditions. We discuss the calibration procedure followed for the activity measurements, the estimation of the uncertainty in the excreted activity, the calculation of detection and quantification limits and estimation of performance indicators. Aspects regarding the spectral analysis, true coincidence summing and matrix effects are also considered.

  5. Assessment of nerve agent exposure: existing and emerging methods.

    PubMed

    Langenberg, Jan P; van der Schans, Marcel J; Noort, Daan

    2009-07-01

    The perceived threat of the use of nerve agents by terrorists against civilian targets implies the need for methods for point-of-care (POC) diagnosis. This review presents an overview of methods that are currently available for the assessment of exposure to nerve agents. Since these methods are mostly MS based, they require complex and expensive equipment and well-trained personnel and, consequently, they are not very suitable for rapid POC diagnosis. However, new technologies are emerging that allow, among others, immunochemical detection of acetylcholinesterase inhibited by nerve agents. Also, lab-on-a-chip methodologies are under development. It is anticipated that MS methods will be suitable for POC diagnosis within a few years, due to the miniaturization of equipment and the emergence of methodologies that enable mass spectrometric analysis with little sample pretreatment and that are potentially fieldable, such as direct analysis in real time and desorption electrospray ionization MS.

  6. Exposure assessment procedures in presence of wideband digital wireless networks.

    PubMed

    Trinchero, D

    2009-12-01

    The article analyses the applicability of traditional methods, as well as recently proposed techniques, to the exposure assessment of electromagnetic field generated by wireless transmitters. As is well known, a correct measurement of the electromagnetic field is conditioned by the complexity of the signal, which requires dedicated instruments or specifically developed extrapolation techniques. Nevertheless, it is also influenced by the typology of the deployment of the transmitting and receiving stations, which varies from network to network. These aspects have been intensively analysed in the literature and several cases of study are available for review. The present article collects the most recent analyses and discusses their applicability to different scenarios, typical of the main wireless networking applications: broadcasting services, mobile cellular networks and data access provisioning infrastructures.

  7. Efficient assessment of exposure to manual lifting using company data.

    PubMed

    van der Beek, Allard J; Mathiassen, Svend Erik; Burdorf, Alex

    2013-05-01

    The objective of this study, based on an extensive dataset on manual materials handling during scaffolding, was to explore whether routinely collected company data can be used to estimate exposure to manual lifting. The number of manual lifts of scaffold parts while constructing/dismantling scaffolds was well predicted by the number of scaffolders in the team and the type of worksite, in combination with company data of either the number of scaffold parts or the scaffold volume. The proportion of explained variance in the number of lifts ranged from 77% to 92%, depending on the variables in the model. Data on scaffold parts and scaffold volume can easily be obtained from the company's administration, since this is its usual paperwork supporting logistics and customer invoicing, respectively. We conclude that company data can be a promising source of information for ergonomic practitioners and researchers, to support assessment of manual lifting in scaffolding.

  8. 21st Century Lunar Exploration: Advanced Radiation Exposure Assessment

    NASA Technical Reports Server (NTRS)

    Anderson, Brooke; Clowdsley, Martha; Wilson, John; Nealy, John; Luetke, Nathan

    2006-01-01

    On January 14, 2004 President George W Bush outlined a new vision for NASA that has humans venturing back to the moon by 2020. With this ambitious goal, new tools and models have been developed to help define and predict the amount of space radiation astronauts will be exposed to during transit and habitation on the moon. A representative scenario is used that includes a trajectory from LEO to a Lunar Base, and simplified CAD models for the transit and habitat structures. For this study galactic cosmic rays, solar proton events, and trapped electron and proton environments are simulated using new dynamic environment models to generate energetic electron, and light and heavy ion fluences. Detailed calculations are presented to assess the human exposure for transit segments and surface stays.

  9. Quantitative risk assessment of Listeria monocytogenes in French cold-smoked salmon: I. Quantitative exposure assessment.

    PubMed

    Pouillot, Régis; Miconnet, Nicolas; Afchain, Anne-Laure; Delignette-Muller, Marie Laure; Beaufort, Annie; Rosso, Laurent; Denis, Jean-Baptiste; Cornu, Marie

    2007-06-01

    A quantitative assessment of the exposure to Listeria monocytogenes from cold-smoked salmon (CSS) consumption in France is developed. The general framework is a second-order (or two-dimensional) Monte Carlo simulation, which characterizes the uncertainty and variability of the exposure estimate. The model takes into account the competitive bacterial growth between L. monocytogenes and the background competitive flora from the end of the production line to the consumer phase. An original algorithm is proposed to integrate this growth in conditions of varying temperature. As part of a more general project led by the French Food Safety Agency (Afssa), specific data were acquired and modeled for this quantitative exposure assessment model, particularly time-temperature profiles, prevalence data, and contamination-level data. The sensitivity analysis points out the main influence of the mean temperature in household refrigerators and the prevalence of contaminated CSS on the exposure level. The outputs of this model can be used as inputs for further risk assessment.

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

    PubMed

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

    2017-01-01

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

  11. ASSESSING POPULATION EXPOSURES TO MULTIPLE AIR POLLUTANTS USING A MECHANISTIC SOURCE-TO-DOSE MODELING FRAMEWORK

    EPA Science Inventory

    The Modeling Environment for Total Risks studies (MENTOR) system, combined with an extension of the SHEDS (Stochastic Human Exposure and Dose Simulation) methodology, provide a mechanistically consistent framework for conducting source-to-dose exposure assessments of multiple pol...

  12. Deoxynivalenol Exposure Assessment for Pregnant Women in Bangladesh.

    PubMed

    Ali, Nurshad; Blaszkewicz, Meinolf; Al Nahid, Abdullah; Rahman, Mustafizur; Degen, Gisela H

    2015-09-24

    The trichothecene mycotoxin deoxynivalenol (DON) is a contaminant of crops worldwide and known to cause adverse health effects in exposed animals and humans. A small survey reported the presence of DON in maize samples in Bangladesh, but these data are insufficient to assess human exposure, and also, biomonitoring data are still scarce. The present study applied biomarker analysis to investigate the DON exposure of pregnant women in Bangladesh. Urine samples were collected from pregnant women living in a rural (n = 32) and in a suburban (n = 22) area of the country. Urines were subjected to enzymatic hydrolysis of glucuronic acid conjugates and to immunoaffinity column clean-up prior to LC-MS/MS analysis of DON and its de-epoxy metabolite DOM-1. The limits of detection (LOD) for DON and DOM-1 in urine were 0.16 ng/mL and 0.10 ng/mL, respectively. DOM-1 was not detected in any of the urines, whilst DON was detectable in 52% of the samples at levels ranging from 0.18-7.16 ng/mL and a mean DON concentration of 0.86 ± 1.57 ng/mL or 2.14 ± 4.74 ng/mg creatinine. A significant difference in mean urinary DON levels was found between the rural (0.47 ± 0.73 ng/mL) and suburban (1.44 ± 2.20 ng/mL) cohort, which may be related to different food habits in the two cohorts. Analysis of food consumption data for the participants did not show significant correlations between their intake of typical staple foods and DON levels in urine. The biomarker concentrations found and published urinary excretion rates for DON were used to estimate daily mycotoxin intake in the cohort: the mean DON intake was 0.05 µg/kg b.w., and the maximum intake was 0.46 µg/kg b.w., values lower than the tolerable daily intake of 1 µg/kg b.w. These first results indicate a low dietary exposure of pregnant women in Bangladesh to DON. Nonetheless, further biomonitoring studies in children and in adult cohorts from other parts of the country are of interest to gain more insight into DON exposure in the

  13. Lead (Pb) quantification in potable water samples: implications for regulatory compliance and assessment of human exposure.

    PubMed

    Triantafyllidou, Simoni; Nguyen, Caroline K; Zhang, Yan; Edwards, Marc A

    2013-02-01

    Assessing the health risk from lead (Pb) in potable water requires accurate quantification of the Pb concentration. Under worst-case scenarios of highly contaminated water samples, representative of public health concerns, up to 71-98 % of the total Pb was not quantified if water samples were not mixed thoroughly after standard preservation (i.e., addition of 0.15 % (v/v) HNO(3)). Thorough mixing after standard preservation improved recovery in all samples, but 35-81 % of the total Pb was still un-quantified in some samples. Transfer of samples from one bottle to another also created high errors (40-100 % of the total Pb was un-quantified in transferred samples). Although the United States Environmental Protection Agency's standard protocol avoids most of these errors, certain methods considered EPA-equivalent allow these errors for regulatory compliance sampling. Moreover, routine monitoring for assessment of human Pb exposure in the USA has no standardized protocols for water sample handling and pre-treatment. Overall, while there is no reason to believe that sample handling and pre-treatment dramatically skew regulatory compliance with the US Pb action level, slight variations from one approved protocol to another may cause Pb-in-water health risks to be significantly underestimated, especially for unusual situations of "worst case" individual exposure to highly contaminated water.

  14. Characterizing Aerosolized Particulate As Part Of A Nanoprocess Exposure Assessment

    SciTech Connect

    Jankovic, John Timothy; Ogle, Burton R; Zontek, Tracy L; Hollenbeck, Scott M

    2010-01-01

    The purpose of this effort was to propose important aerosol characterization parameters that should be gathered as part of a nanomaterial hazard assessment and to offer a methodology for applying that data to daily operations. This study documents different ways of characterizing nanoscale materials using an aerosol from a process simulation consisting of a vacuum cleaner motor operating inside an enclosure. The aerosol is composed of insoluble carbon particles plus environmental background constituents. The average air concentration is 2.76E+5 p/cm3. Size measurements of the aerosol indicate > 70% of the particulate is blade-like in shape, 50% of which have a height dimension 100 nm. In terms of an equivalent spherical diameter 0.8% of the particulate is 100 nm in size. The carbon blades are characterized as having a root-mean-square roughness of 75 nm, and average fractal dimension of 2.25. These measures: aerosol chemistry, solubility, shape and size, surface area, number concentration and size distribution are important parameters to collect for current exposure assessment and toxicology and epidemiology studies.

  15. The Role of Arsenic Speciation in Dietary Exposure Assessment and the Need to Include Bioaccessibility and Biotransformation

    EPA Science Inventory

    Chemical form specific exposure assessment for arsenic has long been identified as a source of uncertainty in estimating the risk associated with the aggregate exposure for a population. Some speciation based assessments document occurrence within an exposure route; however, the...

  16. ASSESSING ASTHMATIC CHILDREN'S EXPOSURES TO TOXIC AIR POLLUTANTS AND THE POTENTIAL INHALED DOSES USING TIME ACTIVITY INFORMATION AND ENERGY EXPENDITURE DATA

    EPA Science Inventory

    Accurately quantifying human exposures and the potential doses of various populations to environmental pollutants is critical for the U.S. Environmental Protection Agency to assess and manage human health risks. The Tampa Asthmatic Children's Study (TACS) was a pilot research stu...

  17. A novel approach for exposure assessment in air pollution epidemiological studies using neuro-fuzzy inference systems: Comparison of exposure estimates and exposure-health associations.

    PubMed

    Blanes-Vidal, Victoria; Cantuaria, Manuella Lech; Nadimi, Esmaeil S

    2017-04-01

    Many epidemiological studies have used proximity to sources as air pollution exposure assessment method. However, proximity measures are not generally good surrogates because of their complex non-linear relationship with exposures. Neuro-fuzzy inference systems (NFIS) can be used to map complex non-linear systems, but its usefulness in exposure assessment has not been extensively explored. We present a novel approach for exposure assessment using NFIS, where the inputs of the model were easily-obtainable proximity measures, and the output was residential exposure to an air pollutant. We applied it to a case-study on NH3 pollution, and compared health effects and exposures estimated from NFIS, with those obtained from emission-dispersion models, and linear and non-linear regression proximity models, using 10-fold cross validation. The agreement between emission-dispersion and NFIS exposures was high (Root-mean-square error (RMSE) =0.275, correlation coefficient (r)=0.91) and resulted in similar health effect estimates. Linear models showed poor performance (RMSE=0.527, r=0.59), while non-linear regression models resulted in heterocedasticity, non-normality and clustered data. NFIS could be a useful tool for estimating individual air pollution exposures in epidemiological studies on large populations, when emission-dispersion data are not available. The tradeoff between simplicity and accuracy needs to be considered.

  18. INNOVATIVE APPROACHES TO HUMAN EXPOSURE ASSESSMENT IN ENVIRONMENTAL JUSTICE COMMUNITIES

    EPA Science Inventory

    North Carolina Central University (NCCU) recently began an innovative human exposure research program in collaboration with the U.S. Environmental Protection Agency's National Exposure Research Laboratory in Research Triangle Park, NC. In this project, researchers will examine ...

  19. ASSESSING SUSCEPTIBILITY FROM EARLY-LIFE EXPOSURE TO CARCINOGENS

    EPA Science Inventory

    Cancer risks from childhood exposures to chemicals are generally analyzed using methods based upon exposure from adults, which assumes chemicals are equally potent for inducing risks at these different lifestages. Published literature was evaluated to determine whether there was...

  20. Shrinking the Psoriasis Assessment Gap: Early Gene-Expression Profiling Accurately Predicts Response to Long-Term Treatment.

    PubMed

    Correa da Rosa, Joel; Kim, Jaehwan; Tian, Suyan; Tomalin, Lewis E; Krueger, James G; Suárez-Fariñas, Mayte

    2017-02-01

    There is an "assessment gap" between the moment a patient's response to treatment is biologically determined and when a response can actually be determined clinically. Patients' biochemical profiles are a major determinant of clinical outcome for a given treatment. It is therefore feasible that molecular-level patient information could be used to decrease the assessment gap. Thanks to clinically accessible biopsy samples, high-quality molecular data for psoriasis patients are widely available. Psoriasis is therefore an excellent disease for testing the prospect of predicting treatment outcome from molecular data. Our study shows that gene-expression profiles of psoriasis skin lesions, taken in the first 4 weeks of treatment, can be used to accurately predict (>80% area under the receiver operating characteristic curve) the clinical endpoint at 12 weeks. This could decrease the psoriasis assessment gap by 2 months. We present two distinct prediction modes: a universal predictor, aimed at forecasting the efficacy of untested drugs, and specific predictors aimed at forecasting clinical response to treatment with four specific drugs: etanercept, ustekinumab, adalimumab, and methotrexate. We also develop two forms of prediction: one from detailed, platform-specific data and one from platform-independent, pathway-based data. We show that key biomarkers are associated with responses to drugs and doses and thus provide insight into the biology of pathogenesis reversion.

  1. Issues in assessing environmental exposures to manufactured nanomaterials.

    PubMed

    Loux, Nicholas T; Su, Yee San; Hassan, Sayed M

    2011-09-01

    Manufactured nanomaterials (MNs) are commonly considered to be commercial products possessing at least one dimension in the size range of 10(-9) m to 10(-7) m. As particles in this size range represent the smaller fraction of colloidal particles characterized by dimensions of 10(-9) m to 10(-6) m, they differ from both molecular species and bulk particulate matter in the sense that they are unlikely to exhibit significant settling under normal gravitational conditions and they are also likely to exhibit significantly diminished diffusivities (when compared to truly dissolved species) in environmental media. As air/water, air/soil, and water/soil intermedium transport is governed by diffusive processes in the absence of significant gravitational and inertial impaction processes in environmental systems, models of MN environmental intermedium transport behavior will likely require an emphasis on kinetic approaches. This review focuses on the likely environmental fate and transport of MNs in atmospheric and aquatic systems. Should significant atmospheric MNs emission occur, previous observations suggest that MNs may likely exhibit an atmospheric residence time of ten to twenty days. Moreover, while atmospheric MN aggregates in a size range of 10(-7) m to 10(-6) m will likely be most mobile, they are least likely to deposit in the human respiratory system. An examination of various procedures including the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal particle suspension stability in water indicates that more sophisticated approaches may be necessary in order to develop aquatic exposure models of acceptable uncertainty. In addition, concepts such as Critical Coagulation Concentrations and Critical Zeta Potentials may prove to be quite useful in environmental aquatic exposure assessments.

  2. Issues in Assessing Environmental Exposures to Manufactured Nanomaterials

    PubMed Central

    Loux, Nicholas T.; Su, Yee San; Hassan, Sayed M.

    2011-01-01

    Manufactured nanomaterials (MNs) are commonly considered to be commercial products possessing at least one dimension in the size range of 10−9 m to 10−7 m. As particles in this size range represent the smaller fraction of colloidal particles characterized by dimensions of 10−9 m to 10−6 m, they differ from both molecular species and bulk particulate matter in the sense that they are unlikely to exhibit significant settling under normal gravitational conditions and they are also likely to exhibit significantly diminished diffusivities (when compared to truly dissolved species) in environmental media. As air/water, air/soil, and water/soil intermedium transport is governed by diffusive processes in the absence of significant gravitational and inertial impaction processes in environmental systems, models of MN environmental intermedium transport behavior will likely require an emphasis on kinetic approaches. This review focuses on the likely environmental fate and transport of MNs in atmospheric and aquatic systems. Should significant atmospheric MNs emission occur, previous observations suggest that MNs may likely exhibit an atmospheric residence time of ten to twenty days. Moreover, while atmospheric MN aggregates in a size range of 10−7 m to 10−6 m will likely be most mobile, they are least likely to deposit in the human respiratory system. An examination of various procedures including the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal particle suspension stability in water indicates that more sophisticated approaches may be necessary in order to develop aquatic exposure models of acceptable uncertainty. In addition, concepts such as Critical Coagulation Concentrations and Critical Zeta Potentials may prove to be quite useful in environmental aquatic exposure assessments. PMID:22016703

  3. Accurate dose assessment system for an exposed person utilising radiation transport calculation codes in emergency response to a radiological accident.

    PubMed

    Takahashi, F; Shigemori, Y; Seki, A

    2009-01-01

    A system has been developed to assess radiation dose distribution inside the body of exposed persons in a radiological accident by utilising radiation transport calculation codes-MCNP and MCNPX. The system consists mainly of two parts, pre-processor and post-processor of the radiation transport calculation. Programs for the pre-processor are used to set up a 'problem-dependent' input file, which defines the accident condition and dosimetric quantities to be estimated. The program developed for the post-processor part can effectively indicate dose information based upon the output file of the code. All of the programs in the dosimetry system can be executed with a generally used personal computer and accurately give the dose profile to an exposed person in a radiological accident without complicated procedures. An experiment using a physical phantom was carried out to verify the availability of the dosimetry system with the developed programs in a gamma ray irradiation field.

  4. Risk Assessment Strategies and Techniques for Combined Exposures

    EPA Science Inventory

    Author: Cynthia V. Rider, Ph.D., and Jane Ellen Simmons, Ph.D.Abstract: Consideration of cumulative risk is necessary to evaluate properly the safety of, and the risks associated with, combined exposures. These combined exposures ("mixtures") commonly occur from exposure to: envi...

  5. Population-Based Assessment of Exposure to Risk Behaviors in Motion Pictures.

    PubMed

    Sargent, James D; Worth, Keilah A; Beach, Michael; Gerrard, Meg; Heatherton, Todd F

    2008-01-01

    The aim of most population-based studies of media is to relate a specific exposure to an outcome of interest. A research program has been developed that evaluates exposure to different components of movies in an attempt of assess the association of such exposure with the adoption of substance use during adolescence. To assess exposure to movie substance use, one must measure both viewing time and content. In developing the exposure measure, the study team was interested in circumventing a common problem in exposure measurement, where measures often conflate exposure to media with attention to media. Our aim in this paper is to present a validated measure of exposure to entertainment media, the Beach method, which combines recognition of a movie title with content analysis of the movie for substance use, to generate population based measures of exposure to substance use in this form of entertainment.

  6. Children exposure assessment to ultrafine particles and black carbon: The role of transport and cooking activities

    NASA Astrophysics Data System (ADS)

    Buonanno, G.; Stabile, L.; Morawska, L.; Russi, A.

    2013-11-01

    An accurate evaluation of the airborne particle dose-response relationship requires detailed measurements of the actual particle concentration levels that people are exposed to, in every microenvironment in which they reside. The aim of this work was to perform an exposure assessment of children in relation to two different aerosol species: ultrafine particles (UFPs) and black carbon (BC). To this purpose, personal exposure measurements, in terms of UFP and BC concentrations, were performed on 103 children aged 8-11 years (10.1 ± 1.1 years) using hand-held particle counters and aethalometers. Simultaneously, a time-activity diary and a portable GPS were used to determine the children's daily time-activity pattern and estimate their inhaled dose of UFPs and BC. The median concentration to which the study population was exposed was found to be comparable to the high levels typically detected in urban traffic microenvironments, in terms of both particle number (2.2 × 104 part. cm-3) and BC (3.8 μg m-3) concentrations. Daily inhaled doses were also found to be relatively high and were equal to 3.35 × 1011 part. day-1 and 3.92 × 101 μg day-1 for UFPs and BC, respectively. Cooking and using transportation were recognized as the main activities contributing to overall daily exposure, when normalized according to their corresponding time contribution for UFPs and BC, respectively. Therefore, UFPs and BC could represent tracers of children exposure to particulate pollution from indoor cooking activities and transportation microenvironments, respectively.

  7. CHILDREN'S DIETARY EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    The Food Quality Protection Act of 1996 requires EPA to more accurately assess children's aggregate exposures to environmental contaminants. Children have unstructured eating behaviors which cause excess exposures as a result of their activities. Determining total dietary intak...

  8. Guidelines for Exposure Assessment in Health Risk Studies Following a Nuclear Reactor Accident

    PubMed Central

    Bouville, André; Linet, Martha S.; Hatch, Maureen; Mabuchi, Kiyohiko

    2013-01-01

    Background: Worldwide concerns regarding health effects after the Chernobyl and Fukushima nuclear power plant accidents indicate a clear need to identify short- and long-term health impacts that might result from accidents in the future. Fundamental to addressing this problem are reliable and accurate radiation dose estimates for the affected populations. The available guidance for activities following nuclear accidents is limited with regard to strategies for dose assessment in health risk studies. Objectives: Here we propose a comprehensive systematic approach to estimating radiation doses for the evaluation of health risks resulting from a nuclear power plant accident, reflected in a set of seven guidelines. Discussion: Four major nuclear reactor accidents have occurred during the history of nuclear power production. The circumstances leading to these accidents were varied, as were the magnitude of the releases of radioactive materials, the pathways by which persons were exposed, the data collected afterward, and the lifestyle factors and dietary consumption that played an important role in the associated radiation exposure of the affected populations. Accidents involving nuclear reactors may occur in the future under a variety of conditions. The guidelines we recommend here are intended to facilitate obtaining reliable dose estimations for a range of different exposure conditions. We recognize that full implementation of the proposed approach may not always be feasible because of other priorities during the nuclear accident emergency and because of limited resources in manpower and equipment. Conclusions: The proposed approach can serve as a basis to optimize the value of radiation dose reconstruction following a nuclear reactor accident. Citation: Bouville A, Linet MS, Hatch M, Mabuchi K, Simon SL. 2014. Guidelines for exposure assessment in health risk studies following a nuclear reactor accident. Environ Health Perspect 122:1–5; http://dx.doi.org/10

  9. Pulmonary function in beryllium workers: assessment of exposure.

    PubMed Central

    Kriebel, D; Sprince, N L; Eisen, E A; Greaves, I A

    1988-01-01

    The inhalation of beryllium causes a serious lung disease characterised by pronounced radiographic and functional impairments and occurs in workers engaged in the extraction and manufacture of the metal. This paper describes the beryllium exposure levels and refining processes in a large beryllium factory operating since the 1930s. Lifetime beryllium exposure histories were estimated for the 309 workers present at a health survey conducted in 1977. Beryllium exposure levels in the plant were high for many years, with some estimated exposure levels in excess of 100 micrograms/m3. As late as 1975, there were exposures to beryllium above 10 micrograms/m3 in some jobs. After about 1977, the plant was in compliance with the permissible exposure limit of 2.0 micrograms/m3. The median cumulative exposure in this cohort was 65 micrograms/m3-years and the median duration of exposure was 17 years. From these data a series of exposure parameters, functions of the exposure histories that characterise biologically important dimensions of exposure were calculated for each worker. PMID:3342199

  10. [Advances of study on assessing exposure to disinfection by-products in drinking water].

    PubMed

    Ye, Bixiong; Wang, Wuyi

    2009-07-01

    DBP exposure assessment issues were addressed. The basic definition to exposure assessment was introduced. Recommended ideal set of drinking water quality parameters to collect for each water treatment plant and specific disinfection by-products to be considered for future studies to adequately characterize DBP exposure were sum up. Previous studies and shortcoming of DBP exposure assessment were discussed and considered. Two examples of DBP exposure assessment were used to explain the progress and method of assessment in detail. Various disciplines to develop better approaches for measuring DBP exposure and greater collaboration of epidemiologists with water utilities and regulators should be encouraged in order to make regulatory monitoring data more useful for epidemiologic studies.

  11. APPLICATION OF THE EXPOSURE DOSE ESTIMATING MODEL (ERDEM) TO ASSESSMENT OF DERMAL EXPOSURE IN THE RAT TO MALATHION

    EPA Science Inventory

    APPLICATION OF THE EXPOSURE DOSE ESTIMATING MODEL (ERDEM) TO ASSESSMENT OF DERMAL EXPOSURE IN THE RAT TO MALATHION.
    Evans, M.V1., Power, F.W2., Dary, C.C2., Tornero-Velez, R2., and Blancato, J.N2.
    1 NHEERL, US EPA, ORD, ETD, RTP, NC; 2 NERL, US EPA, ORD, EDRB, LV, NV
    Re...

  12. Exposure assessment of mycotoxins in cow's milk in Argentina.

    PubMed

    Signorini, M L; Gaggiotti, M; Molineri, A; Chiericatti, C A; Zapata de Basílico, M L; Basílico, J C; Pisani, M

    2012-02-01

    A stochastic simulation model was developed to carry out the first quantitative risk exposure assessment of the mycotoxin level in cow's milk produced in Argentina. The prevalence and concentration of aflatoxin M1 (AFM1), deoxynivalenol (DON) and zearalenone (ZEA) were modeled at various stages through milk processes complying with Argentinean practices. Concentration of AFM1 (0.059ppb), DON (0.338ppb) and ZEA (0.125ppb) in dairy milk were estimated. The proportion of feed samples that exceeded the maximum level accepted by European regulations for AFB1, DON and ZEA were estimated at 25.07%, 0.0% and 8.9%, respectively. The percentage of milk samples that exceeded the maximum level accepted for AFB1 by the MERCOSUR (0.5ppb) and the European Union regulations (0.05ppb) were 0.81 and 32.65, respectively. The probability distribution of AFM1 concentration in milk was affected by the carry-over rate equations applied in the model. Mycotoxin levels in corn silage and concentrated feeds were the factors most correlated with mycotoxin concentrations in milk. Therefore, agricultural practices, crop management and feed production require prompt attention regarding mycotoxin issues.

  13. Exposure assessment and lung function in pig and poultry farmers

    PubMed Central

    Radon, K; Weber, C; Iversen, M; Danuser, B; Pedersen, S; Nowak, D

    2001-01-01

    OBJECTIVES—To describe the relation between spirometric findings and farming characteristics and variables of exposure to organic dust measured during work in animal buildings. Farmers have traditionally been described as having one of the most dangerous occupations, so a large scale study on European farmers was carried out. This is the report of the second part of that study.
METHODS—40 pig farmers in Denmark and 36 poultry farmers in Switzerland were chosen randomly and were assessed over 1 working day.
RESULTS—Mean (SD) baseline spirometric results in pig farmers were higher than in poultry farmers (forced expiratory volume in 1 second (FEV1) (% of reference value) 108.3 (16.7) v 100.2 (14.2); p=0.04). Baseline lung function results were significantly associated with ventilation of the animal houses. Furthermore, temperature was related to spirometric findings in pig farmers.
CONCLUSIONS—Ventilation of the animal house and temperature might influence respiratory morbidity in farmers.


Keywords: ventilation; micro-organism; European multicentre study PMID:11351057

  14. Exposure Assessment of the Tehran Population (Iran) to Zearalenone Mycotoxin

    PubMed Central

    Yazdanpanah, Hassan; Zarghi, Afshin; Shafaati, Ali Reza; Foroutan, Seyyed Mohsen; Aboul-Fathi, Farshid; Khoddam, Arash; Nazari, Firoozeh

    2012-01-01

    Zearalenone (ZEA) mycotoxin is a potent estrogenic metabolite. It is the primary toxin causing infertility, abortion or other breeding problems. A HPLC method was validated for ZEA in foods using a monolithic column with sample clean-up on an immunoaffinity column. A certified reference material (CRM) from FAPAS (UK) was analyzed. A survey of ZEA was performed on the 72 samples of rice, bread, puffed corn snack and wheat flour collected from Tehran retail market. The average recovery and coefficient of variation in different foods ranged 92.7-107.1 and 4.9-13.8%, respectively. The amount of ZEA in corn CRM was in the acceptable range of FAPAS. The limit of quantification was 3 ng/g for rice, bread and wheat flour and 2.7 ng/g for puffed corn snack. The retention time of zearalenone was 2.6 min. All samples had contamination level lower than the maximum tolerated level of ZEA in foods in Iran. The mean intake of ZEA from all samples was much lower than the tolerable daily intake estimated by JECFA. This is the first survey on ZEA contamination in bread and rice in Iran as well as the first study on exposure assessment of Tehran population to ZEA. PMID:24250447

  15. Critical factors in assessing risk from exposure to nasal carcinogens.

    PubMed

    Bogdanffy, M S; Mathison, B H; Kuykendall, J R; Harman, A E

    1997-10-31

    Anatomical, physiological, biochemical and molecular factors that contribute to chemical-induced nasal carcinogenesis are either largely divergent between test species and humans, or we know very little of them. These factors, let alone the uncertainty associated with our knowledge gap, present a risk assessor with the formidable task of making judgments about risks to human health from exposure to chemicals that have been identified in rodent studies to be nasal carcinogens. This paper summarizes some of the critical attributes of the hazard identification and dose-response aspects of risk assessments for nasal carcinogens that must be accounted for by risk assessors in order to make informed decisions. Data on two example compounds, dimethyl sulfate and hexamethylphosphoramide, are discussed to illustrate the diversity of information that can be used to develop informed hypotheses about mode of action and decisions on appropriate dosimeters for interspecies extrapolation. Default approaches to interspecies dosimetry extrapolation are described briefly and are followed by a discussion of a generalized physiologically based pharmacokinetic model that, unlike default approaches, is flexible and capable of incorporating many of the critical species-specific factors. Recent advancements in interspecies nasal dosimetry modeling are remarkable. However, it is concluded that without the development of research programs aimed at understanding carcinogenic susceptibility factors in human and rodent nasal tissues, development of plausible modes of action will lag behind the advancements made in dosimetry modeling.

  16. Assessment of bioaerosols and inhalable dust exposure in Swiss sawmills.

    PubMed

    Oppliger, Anne; Rusca, Sophie; Charrière, Nicole; Vu Duc, Trinh; Droz, Pierre-Olivier

    2005-07-01

    An assessment of wood workers' exposure to airborne cultivable bacteria, fungi, inhalable endotoxins and inhalable organic dust was performed at 12 sawmills that process mainly coniferous wood species. In each plant, samples were collected at four or five different work sites (debarking, sawing, sorting, planing and sawing cockpit) and the efficiency of sampling devices (impinger or filter) for determining endotoxins levels was evaluated. Results show that fungi are present in very high concentrations (up to 35 000 CFU m(-3)) in all sawmills. We also find that there are more bioaerosols at the sorting work site (mean +/- SD: 7723 +/- 9919 CFU m(-3) for total bacteria, 614 +/- 902 CFU m(-3) for Gram-negative, 19 438 +/- 14 246 CFU m(-3) for fungi, 7.0 +/- 9.0 EU m(-3) for endotoxin and 2.9 +/- 4.8 g m(-3) for dust) than at the sawing station (mean +/- SD: 1938 +/- 2478 CFU m(-3) for total bacteria, 141 +/- 206 CFU m(-3) for Gram-negative, 12 207 +/- 10 008 CFU m(-3) for fungi, 2.1 +/- 1.9 EU m(-3) for endotoxin and 0.75 +/- 0.49 mg m(-3) for dust). At the same time, the species composition and concentration of airborne Gram-negative bacteria were studied. Penicillinium sp. were the predominant fungi, while Bacillus sp. and the Pseudomonadacea family were the predominant Gram-positive and Gram-negative bacteria encountered, respectively.

  17. Methodological Issues in Assessing the Impact of Prenatal Drug Exposure

    PubMed Central

    Konijnenberg, Carolien

    2015-01-01

    Prenatal drug exposure is a common public health concern that can result in perinatal complications, birth defects, and developmental disorders. The growing literature regarding the effects of prenatal exposure to specific drugs such as tobacco, alcohol, cocaine, and heroin is often conflicting and constantly changing. This review discusses several reasons why the effects of prenatal drug exposure are so difficult to determine, including variations in dose, timing, duration of exposure, polydrug use, unreliable measures of drug exposure, latent or “sleeper” effects, genetic factors, and socioenvironmental influences. In addition to providing research guidelines, this review also aims to help clinicians and policy makers to identify the strengths and weaknesses in studies investigating the effects of prenatal drug exposure. This knowledge may be used to make better informed decisions regarding the appropriate treatment for pregnant, drug-dependent women and their children. PMID:26604776

  18. Rapid and accurate assessment of seizure liability of drugs by using an optimal support vector machine method.

    PubMed

    Zhang, Hui; Li, Wei; Xie, Yang; Wang, Wen-Jing; Li, Lin-Li; Yang, Sheng-Yong

    2011-12-01

    Drug-induced seizures are a serious adverse effect and assessment of seizure risk usually takes place at the late stage of drug discovery process, which does not allow sufficient time to reduce the risk by chemical modification. Thus early identification of chemicals with seizure liability using rapid and cheaper approaches would be preferable. In this study, an optimal support vector machine (SVM) modeling method has been employed to develop a prediction model of seizure liability of chemicals. A set of 680 compounds were used to train the SVM model. The established SVM model was then validated by an independent test set comprising 175 compounds, which gave a prediction accuracy of 86.9%. Further, the SVM-based prediction model of seizure liability was compared with various preclinical seizure assays, including in vitro rat hippocampal brain slice, in vivo zebrafish larvae assay, mouse spontaneous seizure model, and mouse EEG model. In terms of predictability, the SVM model was ranked just behind the mouse EEG model, but better than the rat brain slice and zebrafish models. Nevertheless, the SVM model has considerable advantages compared with the preclinical seizure assays in speed and cost. In summary, the SVM-based prediction model of seizure liability established here offers potential as a cheaper, rapid and accurate assessment of seizure liability of drugs, which could be used in the seizure risk assessment at the early stage of drug discovery. The prediction model is freely available online at http://www.sklb.scu.edu.cn/lab/yangsy/download/ADMET/seizure_pred.tar.

  19. Integrating smart-phone based momentary location tracking with fixed site air quality monitoring for personal exposure assessment.

    PubMed

    Su, Jason G; Jerrett, Michael; Meng, Ying-Ying; Pickett, Melissa; Ritz, Beate

    2015-02-15

    Epidemiological studies investigating relationships between environmental exposures from air pollution and health typically use residential addresses as a single point for exposure, while environmental exposures in transit, at work, school or other locations are largely ignored. Personal exposure monitors measure individuals' exposures over time; however, current personal monitors are intrusive and cannot be operated at a large scale over an extended period of time (e.g., for a continuous three months) and can be very costly. In addition, spatial locations typically cannot be identified when only personal monitors are used. In this paper, we piloted a study that applied momentary location tracking services supplied by smart phones to identify an individual's location in space-time for three consecutive months (April 28 to July 28, 2013) using available Wi-Fi networks. Individual exposures in space-time to the traffic-related pollutants Nitrogen Oxides (NOX) were estimated by superimposing an annual mean NOX concentration surface modeled using the Land Use Regression (LUR) modeling technique. Individual's exposures were assigned to stationary (including home, work and other stationary locations) and in-transit (including commute and other travel) locations. For the individual, whose home/work addresses were known and the commute route was fixed, it was found that 95.3% of the time, the individual could be accurately identified in space-time. The ambient concentration estimated at the home location was 21.01 ppb. When indoor/outdoor infiltration, indoor sources of air pollution and time spent outdoors were taken into consideration, the individual's cumulative exposures were 28.59 ppb and 96.49 ppb, assuming a respective indoor/outdoor ratio of 1.33 and 5.00. Integrating momentary location tracking services with fixed-site field monitoring, plus indoor-outdoor air exchange calibration, makes exposure assessment of a very large population over an extended time period

  20. METHODOLOGY FOR THE EVALUATION OF CUMULATIVE EPISODIC EXPOSURE TO CHEMICAL STRESSORS IN AQUATIC RISK ASSESSMENT.

    EPA Science Inventory

    An ecological risk assessment method was developed to evaluate the magnitude, duration, and episodic nature of chemical stressors on aquatic communities. The percent of an ecosystem's species at risk from a designated chemical exposure scenario is generated. In effects assessment...

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

    SciTech Connect

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

    2008-11-15

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

  2. Polyfluoroalkyl Chemicals and Learning and Developmental Disorders: Epidemiology and Exposure Assessment

    ERIC Educational Resources Information Center

    Hoffman, Jennifer Kate

    2010-01-01

    This dissertation has two areas of focus: learning and developmental disorders (LDDs) and polyfluoroalkyl chemicals (PFCs). Epidemiological and exposure assessment methods are applied to each. The first paper used geographic location as a surrogate for exposure and broadly assesses the effect of the environment, both physical and social, on LDD…

  3. Developing and Evaluating New Methods for Assessing Concurrent Environmental Exposures

    EPA Science Inventory

    Summary of purpose and scope (no longer than 200 words): One limitation to current environmental health research is the focus on single contaminant exposures. Each exposure estimated in epidemiologic models accounts for a relatively small proportion of observed variance in health...

  4. DATA REQUIREMENTS FOR ASSESSING CHILDREN'S EXPOSURE TO PESTICIDES

    EPA Science Inventory

    Several multimedia, multipathway exposure monitoring studies are currently being planned within EPA/NERL. The overall objectives of these studies are (1) to develop the data and models that can be used to estimate exposure and dose for young children to pesticides and (2) to i...

  5. Assessment of exposures to fecally-contaminated recreational water

    EPA Science Inventory

    Exposure to fecally-contaminated recreational waters can pose a health risk to swimmers and other recreators. Since 2003, we have interviewed nearly 27,000 respondents at seven beaches impacted by treated sewage discharge. Information was collected about the duration and exposure...

  6. Advancing Exposure Characterization for Chemical Evaluation and Risk Assessment

    EPA Science Inventory

    A new generation of scientific tools has emerged to rapidly measure signals from cells, tissues, and organisms following exposure to chemicals. High-visibility efforts to apply these tools for efficient toxicity testing raise important research questions in exposure science. As v...

  7. Interpretation of benzene biomarkers of exposure for risk assessment

    EPA Science Inventory

    Human biomarkers of exposure such as parent or metabolite concentrations in blood or urine are often reported without any context to the sources of exposure or the implications for human risk. The Biomonitoring Technical Committee of the International Life Sciences Institute/Huma...

  8. #2 - An Empirical Assessment of Exposure Measurement Error ...

    EPA Pesticide Factsheets

    Background• Differing degrees of exposure error acrosspollutants• Previous focus on quantifying and accounting forexposure error in single-pollutant models• Examine exposure errors for multiple pollutantsand provide insights on the potential for bias andattenuation of effect estimates in single and bipollutantepidemiological models The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.

  9. Assessment of mercury exposure among small-scale gold miners using mercury stable isotopes.

    PubMed

    Sherman, Laura S; Blum, Joel D; Basu, Niladri; Rajaee, Mozhgon; Evers, David C; Buck, David G; Petrlik, Jindrich; DiGangi, Joseph

    2015-02-01

    Total mercury (Hg) concentrations in hair and urine are often used as biomarkers of exposure to fish-derived methylmercury (MeHg) and gaseous elemental Hg, respectively. We used Hg stable isotopes to assess the validity of these biomarkers among small-scale gold mining populations in Ghana and Indonesia. Urine from Ghanaian miners displayed similar Δ(199)Hg values to Hg derived from ore deposits (mean urine Δ(199)Hg=0.01‰, n=6). This suggests that urine total Hg concentrations accurately reflect exposure to inorganic Hg among this population. Hair samples from Ghanaian miners displayed low positive Δ(199)Hg values (0.23-0.55‰, n=6) and low percentages of total Hg as MeHg (7.6-29%, n=7). These data suggest that the majority of the Hg in these miners' hair samples is exogenously adsorbed inorganic Hg and not fish-derived MeHg. Hair samples from Indonesian gold miners who eat fish daily displayed a wider range of positive Δ(199)Hg values (0.21-1.32‰, n=5) and percentages of total Hg as MeHg (32-72%, n=4). This suggests that total Hg in the hair samples from Indonesian gold miners is likely a mixture of ingested fish MeHg and exogenously adsorbed inorganic Hg. Based on data from both populations, we suggest that total Hg concentrations in hair samples from small-scale gold miners likely overestimate exposure to MeHg from fish consumption.

  10. Modelling personal exposure to particulate air pollution: an assessment of time-integrated activity modelling, Monte Carlo simulation & artificial neural network approaches.

    PubMed

    McCreddin, A; Alam, M S; McNabola, A

    2015-01-01

    An experimental assessment of personal exposure to PM10 in 59 office workers was carried out in Dublin, Ireland. 255 samples of 24-h personal exposure were collected in real time over a 28 month period. A series of modelling techniques were subsequently assessed for their ability to predict 24-h personal exposure to PM10. Artificial neural network modelling, Monte Carlo simulation and time-activity based models were developed and compared. The results of the investigation showed that using the Monte Carlo technique to randomly select concentrations from statistical distributions of exposure concentrations in typical microenvironments encountered by office workers produced the most accurate results, based on 3 statistical measures of model performance. The Monte Carlo simulation technique was also shown to have the greatest potential utility over the other techniques, in terms of predicting personal exposure without the need for further monitoring data. Over the 28 month period only a very weak correlation was found between background air quality and personal exposure measurements, highlighting the need for accurate models of personal exposure in epidemiological studies.

  11. Probabilistic assessment of exposure to cosmetic products by French children aged 0-3 years.

    PubMed

    Ficheux, A S; Dornic, N; Bernard, A; Chevillotte, G; Roudot, A C

    2016-08-01

    Very few exposure data are available for children in Europe and worldwide. The aim of this study was to assess the exposure to cosmetic products used on children aged 0-3 years using recent consumption data generated for the French population. Exposure was assessed using a probabilistic method for 24 products including cleanser, skin care, fragrance, solar and bottom products. The exposure data obtained in this study for children aged 0-3 years were higher than the values fixed by the SCCS for all common products: liquid shampoo, face moisturizer cream, toothpaste, shower gel and body moisturizer cream. Exposure was assessed for the first time for many products such as sunscreens, Eau de toilette and massage products. These new French exposure values will be useful for safety assessors and for safety agencies.

  12. Turbulent eddy diffusion models in exposure assessment - Determination of the eddy diffusion coefficient.

    PubMed

    Shao, Yuan; Ramachandran, Sandhya; Arnold, Susan; Ramachandran, Gurumurthy

    2017-03-01

    The use of the turbulent eddy diffusion model and its variants in exposure assessment is limited due to the lack of knowledge regarding the isotropic eddy diffusion coefficient, DT. But some studies have suggested a possible relationship between DT and the air changes per hour (ACH) through a room. The main goal of this study was to accurately estimate DT for a range of ACH values by minimizing the difference between the concentrations measured and predicted by eddy diffusion model. We constructed an experimental chamber with a spatial concentration gradient away from the contaminant source, and conducted 27 3-hr long experiments using toluene and acetone under different air flow conditions (0.43-2.89 ACHs). An eddy diffusion model accounting for chamber boundary, general ventilation, and advection was developed. A mathematical expression for the slope based on the geometrical parameters of the ventilation system was also derived. There is a strong linear relationship between DT and ACH, providing a surrogate parameter for estimating DT in real-life settings. For the first time, a mathematical expression for the relationship between DT and ACH has been derived that also corrects for non-ideal conditions, and the calculated value of the slope between these two parameters is very close to the experimentally determined value. The values of DT obtained from the experiments are generally consistent with values reported in the literature. They are also independent of averaging time of measurements, allowing for comparison of values obtained from different measurement settings. These findings make the use of turbulent eddy diffusion models for exposure assessment in workplace/indoor environments more practical.

  13. HOW CAN BIOMONITORING INFORM EXPOSURE ASSESSMENT? PERMETHRIN A CASE STUDY.

    EPA Science Inventory

    Biomonitoring is an important tool for understanding the linkages between external chemical exposures, internal doses and potential health outcomes in humans. In recent years, there has been an explosion of available human biomonitoring data from scientists.

  14. USING BIOMONITORING DATA TO INFORM EXPOSURE ASSESSMENT IN CHILDREN

    EPA Science Inventory

    Discussing the challenges associated with estimating and interpreting toxicant exposures and health risks from biomonitoring data. Extended abstract will also be translated in Spanish and published in Acta Toxicologica Argentina.

  15. LESSONS LEARNED FROM THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS)

    EPA Science Inventory

    Three NHEXAS Studies were conducted from 1995-1997 to evaluate total human exposure to multiple chemicals on community and regional scales. EPA established cooperative agreements with three Consortia to conduct three interrelated NHEXAS field studies. The University of Arizona...

  16. The application of intraoperative transit time flow measurement to accurately assess anastomotic quality in sequential vein grafting

    PubMed Central

    Yu, Yang; Zhang, Fan; Gao, Ming-Xin; Li, Hai-Tao; Li, Jing-Xing; Song, Wei; Huang, Xin-Sheng; Gu, Cheng-Xiong

    2013-01-01

    OBJECTIVES Intraoperative transit time flow measurement (TTFM) is widely used to assess anastomotic quality in coronary artery bypass grafting (CABG). However, in sequential vein grafting, the flow characteristics collected by the conventional TTFM method are usually associated with total graft flow and might not accurately indicate the quality of every distal anastomosis in a sequential graft. The purpose of our study was to examine a new TTFM method that could assess the quality of each distal anastomosis in a sequential graft more reliably than the conventional TTFM approach. METHODS Two TTFM methods were tested in 84 patients who underwent sequential saphenous off-pump CABG in Beijing An Zhen Hospital between April and August 2012. In the conventional TTFM method, normal blood flow in the sequential graft was maintained during the measurement, and the flow probe was placed a few centimetres above the anastomosis to be evaluated. In the new method, blood flow in the sequential graft was temporarily reduced during the measurement by placing an atraumatic bulldog clamp at the graft a few centimetres distal to the anastomosis to be evaluated, while the position of the flow probe remained the same as in the conventional method. This new TTFM method was named the flow reduction TTFM. Graft flow parameters measured by both methods were compared. RESULTS Compared with the conventional TTFM, the flow reduction TTFM resulted in significantly lower mean graft blood flow (P < 0.05); in contrast, yielded significantly higher pulsatility index (P < 0.05). Diastolic filling was not significantly different between the two methods and was >50% in both cases. Interestingly, the flow reduction TTFM identified two defective middle distal anastomoses that the conventional TTFM failed to detect. Graft flows near the defective distal anastomoses were improved substantially after revision. CONCLUSIONS In this study, we found that temporary reduction of graft flow during TTFM seemed to

  17. Radiochromic film dosimetry with flatbed scanners: A fast and accurate method for dose calibration and uniformity correction with single film exposure

    SciTech Connect

    Menegotti, L.; Delana, A.; Martignano, A.

    2008-07-15

    Film dosimetry is an attractive tool for dose distribution verification in intensity modulated radiotherapy (IMRT). A critical aspect of radiochromic film dosimetry is the scanner used for the readout of the film: the output needs to be calibrated in dose response and corrected for pixel value and spatial dependent nonuniformity caused by light scattering; these procedures can take a long time. A method for a fast and accurate calibration and uniformity correction for radiochromic film dosimetry is presented: a single film exposure is used to do both calibration and correction. Gafchromic EBT films were read with two flatbed charge coupled device scanners (Epson V750 and 1680Pro). The accuracy of the method is investigated with specific dose patterns and an IMRT beam. The comparisons with a two-dimensional array of ionization chambers using a 18x18 cm{sup 2} open field and an inverse pyramid dose pattern show an increment in the percentage of points which pass the gamma analysis (tolerance parameters of 3% and 3 mm), passing from 55% and 64% for the 1680Pro and V750 scanners, respectively, to 94% for both scanners for the 18x18 open field, and from 76% and 75% to 91% for the inverse pyramid pattern. Application to an IMRT beam also shows better gamma index results, passing from 88% and 86% for the two scanners, respectively, to 94% for both. The number of points and dose range considered for correction and calibration appears to be appropriate for use in IMRT verification. The method showed to be fast and to correct properly the nonuniformity and has been adopted for routine clinical IMRT dose verification.

  18. Computational exposure assessment of electromagnetic fields generated by an RFID system for mother--newborn identity reconfirmation.

    PubMed

    Fiocchi, Serena; Parazzini, Marta; Paglialonga, Alessia; Ravazzani, Paolo

    2011-07-01

    Radio frequency identification (RFID) is an innovative technology currently applied in a large number of industrial and consumer applications. The spread of RFID technology does not correspond to a parallel increase in studies on its possible impact on health in terms of electromagnetic field (EMF) exposure. The aim of this paper is to estimate, by computational techniques, the EMF generated by passive RFID systems for mother-newborn identity reconfirmation. The computation was performed on realistic models of newborn and mother for three different reader positions. The compliance with EMF exposure guidelines was investigated as a function of the change in reader-tag specifications (magnetic field threshold and maximum distance of the reader to awake the tag) and time of use of the reader close to the body. The results show that attention should be paid to the identification of the optimal reader-tag technical specifications to be used in this type of application. That should be done by an accurate exposure assessment investigation, in particular for newborn exposure. The need to reduce the exposure time as much as possible indicates the importance of specific training on the practical applications of the RFID (DATALOGIC J-series, Bologna, Italy) device.

  19. Multimedia Environmental Pollutant Assessment System (MEPAS{reg_sign}): Exposure pathway and human health impact assessment models

    SciTech Connect

    Strenge, D.L.; Chamberlain, P.J.

    1995-05-01

    The Multimedia Environmental Pollutant Assessment System (MEPAS) provides physics-based models for human health risk assessment for radioactive and hazardous pollutants. MEPAS analyzes pollutant behavior in various media (air, soil, groundwater and surface water) and estimates transport through and between media and exposure and impacts to the environment, to the maximum individual, and to populations. MEPAS includes 25 exposure pathway models, a database with information on more than 650 contaminants, and a sensitivity module that allows for uncertainty analysis. Four major transport pathways are considered in MEPAS: groundwater, overland, surface water, and atmospheric. This report describes the exposure pathway and health impact assessment component of MEPAS, which provides an estimate of health impacts to selected individuals and populations from exposure to pollutants. The exposure pathway analysis starts with pollutant concentration in a transport medium and estimates the average daily dose to exposed individuals from contact with the transport medium or a secondary medium contaminated by the transport medium. The average daily dose is then used to estimate a measure of health impact appropriate to the type of pollutant considered. Discussions of the exposure pathway models include the assumptions and equations used to convert the transport medium concentrations to exposure medium concentrations. The discussion for a given exposure pathway defines the transport pathways leading to the exposure, the special processes considered in determining the pollutant concentration in the exposure medium, and the exposure model used to estimate the average daily dose. Models for the exposure pathway and health impact assessments require definition of several parameters. A summary of the notation used for these parameters is provided.

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

    PubMed

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

    2017-05-15

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

  1. Assessment of noise exposure during commuting in the Madrid subway.

    PubMed

    Tabacchi, M; Pavón, I; Ausejo, M; Asensio, C; Recuero, M

    2011-09-01

    Because noise-induced hearing impairment is the result not only of occupational noise exposure but also of total daily noise exposure, it is important to take the non-occupational exposure of individuals (during commuting to and from their jobs, at home, and during recreational activities) into account. Mass transit is one of the main contributors to non-occupational noise exposure. We developed a new methodology to estimate a representative commuting noise exposure. The methodology was put into practice for the Madrid subway because of all Spanish subway systems it covers the highest percentage of worker journeys (22.6%). The results of the application highlight that, for Madrid subway passengers, noise exposure level normalized to a nominal 8 hr (L(Ex,8h-cj) ) depends strongly on the type of train, the presence of squealing noise, and the public address audio system, ranging from 68.6 dBA to 72.8 dBA. These values play an important role in a more complete evaluation of a relationship between noise dose and worker health response.

  2. PET optimization for improved assessment and accurate quantification of {sup 90}Y-microsphere biodistribution after radioembolization

    SciTech Connect

    Martí-Climent, Josep M. Prieto, Elena; Elosúa, César; Rodríguez-Fraile, Macarena; Domínguez-Prado, Inés; Vigil, Carmen; García-Velloso, María J.; Arbizu, Javier; Peñuelas, Iván; Richter, José A.

    2014-09-15

    Purpose: {sup 90}Y-microspheres are widely used for the radioembolization of metastatic liver cancer or hepatocellular carcinoma and there is a growing interest for imaging {sup 90}Y-microspheres with PET. The aim of this study is to evaluate the performance of a current generation PET/CT scanner for {sup 90}Y imaging and to optimize the PET protocol to improve the assessment and the quantification of {sup 90}Y-microsphere biodistribution after radioembolization. Methods: Data were acquired on a Biograph mCT-TrueV scanner with time of flight (TOF) and point spread function (PSF) modeling. Spatial resolution was measured with a{sup 90}Y point source. Sensitivity was evaluated using the NEMA 70 cm line source filled with {sup 90}Y. To evaluate the count rate performance, {sup 90}Y vials with activity ranging from 3.64 to 0.035 GBq were measured in the center of the field of view (CFOV). The energy spectrum was evaluated. Image quality with different reconstructions was studied using the Jaszczak phantom containing six hollow spheres (diameters: 31.3, 28.1, 21.8, 16.1, 13.3, and 10.5 mm), filled with a 207 kBq/ml {sup 90}Y concentration and a 5:1 sphere-to-background ratio. Acquisition time was adjusted to simulate the quality of a realistic clinical PET acquisition of a patient treated with SIR-Spheres{sup ®}. The developed methodology was applied to ten patients after SIR-Spheres{sup ®} treatment acquiring a 10 min per bed PET. Results: The energy spectrum showed the{sup 90}Y bremsstrahlung radiation. The {sup 90}Y transverse resolution, with filtered backprojection reconstruction, was 4.5 mm in the CFOV and degraded to 5.0 mm at 10 cm off-axis. {sup 90}Y absolute sensitivity was 0.40 kcps/MBq in the center of the field of view. Tendency of true and random rates as a function of the {sup 90}Y activity could be accurately described using linear and quadratic models, respectively. Phantom studies demonstrated that, due to low count statistics in {sup 90}Y PET

  3. Windsor, Ontario Exposure Assessment Study: Design and Methods Validation of Personal, Indoor and Outdoor Air Pollution Monitoring

    EPA Science Inventory

    The Windsor, Ontario Exposure Assessment Study evaluated the contribution of ambient air pollutants to personal and indoor exposures of adults and asthmatic children living in Windsor, Ontario, Canada. In addition, the role of personal, indoor, and outdoor air pollution exposures...

  4. Assessment of airborne exposure and dermal contact to acrylamide during chemical grouting operations. Final report

    SciTech Connect

    McHugh, J.M.

    1987-07-22

    Acrylamide exposure may occur by inhalation, ingestion and skin absorption; acrylamide is a neurotoxin and an irritant. The report details the results of field studies to assess airborne exposure and dermal contact to acrylamide during chemical grouting operations. Occupational exposures to acrylamide were characterized for sewer mainline, lateral line, and manhole maintenance operations. The objective of the study was to collect exposure data based on observations and measurements to be used as an integral part of a quantitative risk assessment by the U.S. Environmental Protection Agency's Office of Toxic Substances.

  5. Assessment of Prenatal Exposure to Arsenic in Tenerife Island

    PubMed Central

    Vall, Oriol; Gómez-Culebras, Mario; Garcia-Algar, Oscar; Joya, Xavier; Velez, Dinoraz; Rodríguez-Carrasco, Eva; Puig, Carme

    2012-01-01

    Introduction Increasing awareness of the potential chronic health effects of arsenic (As) at low exposure levels has motivated efforts to better understand impaired child development during pregnancy by biomarkers of exposure. The aims of this study were to evaluate the prenatal exposure to As by analysis of an alternative matrix (meconium), to examine its effects on neonatal outcomes and investigate the association with maternal lifestyle and dietary habits during pregnancy. Methods A transversal descriptive study was conducted in Tenerife (Spain). A total of 96 mother-child pairs participated in the study. A questionnaire on sociodemographic, lifestyle and dietary habits during pregnancy was administered the day after the delivery. Analysis of total As in meconium was performed by inductively coupled plasma-optical emission spectrometer. Results Total As was detected in 37 (38.5%) meconium samples. The univariate logistic regression model indicates that prenatal exposure to As was associated with a low intake of eggs per week (OR 0.56; CI (95%): 0.34–0.94) during pregnancy. Conversely, frequent intake of vegetables was associated with prenatal As exposure (OR: 1.19; CI (95%): 1.01–1.41) and frequent intake of processed meat (as bacon, Frankfurt’s sausage, and hamburger) shows a trend to As prenatal exposure (OR: 8.54; CI (95%): 0.80–90.89). The adjusted multivariate logistic regression model indicates that only frequent intake of vegetables maintains the association (OR: 1.31; CI (95%): 1.02–1.68). Conclusion The studied population presented a low As exposure and was not associated with neonatal effects. Maternal consumption of vegetables during pregnancy was associated with detectable meconium As levels; however the concentration detected in meconium was too low to be considered a major public health concern in this geographical area. PMID:23209747

  6. Can Community Health Workers Report Accurately on Births and Deaths? Results of Field Assessments in Ethiopia, Malawi and Mali

    PubMed Central

    Silva, Romesh; Amouzou, Agbessi; Munos, Melinda; Marsh, Andrew; Hazel, Elizabeth; Victora, Cesar; Black, Robert; Bryce, Jennifer

    2016-01-01

    Introduction Most low-income countries lack complete and accurate vital registration systems. As a result, measures of under-five mortality rates rely mostly on household surveys. In collaboration with partners in Ethiopia, Ghana, Malawi, and Mali, we assessed the completeness and accuracy of reporting of births and deaths by community-based health workers, and the accuracy of annualized under-five mortality rate estimates derived from these data. Here we report on results from Ethiopia, Malawi and Mali. Method In all three countries, community health workers (CHWs) were trained, equipped and supported to report pregnancies, births and deaths within defined geographic areas over a period of at least fifteen months. In-country institutions collected these data every month. At each study site, we administered a full birth history (FBH) or full pregnancy history (FPH), to women of reproductive age via a census of households in Mali and via household surveys in Ethiopia and Malawi. Using these FBHs/FPHs as a validation data source, we assessed the completeness of the counts of births and deaths and the accuracy of under-five, infant, and neonatal mortality rates from the community-based method against the retrospective FBH/FPH for rolling twelve-month periods. For each method we calculated total cost, average annual cost per 1,000 population, and average cost per vital event reported. Results On average, CHWs submitted monthly vital event reports for over 95 percent of catchment areas in Ethiopia and Malawi, and for 100 percent of catchment areas in Mali. The completeness of vital events reporting by CHWs varied: we estimated that 30%-90% of annualized expected births (i.e. the number of births estimated using a FPH) were documented by CHWs and 22%-91% of annualized expected under-five deaths were documented by CHWs. Resulting annualized under-five mortality rates based on the CHW vital events reporting were, on average, under-estimated by 28% in Ethiopia, 32% in

  7. Assessing exposure in epidemiologic studies to disinfection by-products in drinking water: report from an international workshop.

    PubMed Central

    Arbuckle, Tye E; Hrudey, Steve E; Krasner, Stuart W; Nuckols, Jay R; Richardson, Susan D; Singer, Philip; Mendola, Pauline; Dodds, Linda; Weisel, Clifford; Ashley, David L; Froese, Kenneth L; Pegram, Rex A; Schultz, Irvin R; Reif, John; Bachand, Annette M; Benoit, Frank M; Lynberg, Michele; Poole, Charles; Waller, Kirsten

    2002-01-01

    The inability to accurately assess exposure has been one of the major shortcomings of epidemiologic studies of disinfection by-products (DBPs) in drinking water. A number of contributing factors include a) limited information on the identity, occurrence, toxicity, and pharmacokinetics of the many DBPs that can be formed from chlorine, chloramine, ozone, and chlorine dioxide disinfection; b) the complex chemical interrelationships between DBPs and other parameters within a municipal water distribution system; and c) difficulties obtaining accurate and reliable information on personal activity and water consumption patterns. In May 2000, an international workshop was held to bring together various disciplines to develop better approaches for measuring DBP exposure for epidemiologic studies. The workshop reached consensus about the clear need to involve relevant disciplines (e.g., chemists, engineers, toxicologists, biostatisticians and epidemiologists) as partners in developing epidemiologic studies of DBPs in drinking water. The workshop concluded that greater collaboration of epidemiologists with water utilities and regulators should be encouraged in order to make regulatory monitoring data more useful for epidemiologic studies. Similarly, exposure classification categories in epidemiologic studies should be chosen to make results useful for regulatory or policy decision making. PMID:11834463

  8. Quantitative Plasma Biomarker Analysis in HDI Exposure Assessment

    PubMed Central

    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 ≤0.02–0.92 μg 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 ∼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 ∼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. PMID:19805392

  9. National Human Exposure Assessment Survey: analysis of exposure pathways and routes for arsenic and lead in EPA Region 5.

    PubMed

    Clayton, C A; Pellizzari, E D; Quackenboss, J J

    2002-01-01

    The National Human Exposure Assessment Survey (NHEXAS) Phase I field study conducted in EPA Region 5 (Great Lakes Area) provides extensive exposure data on a representative sample of approximately 250 residents of the region. Associated environmental media and biomarker (blood, urine) concentration data were also obtained for the study participants to aid in understanding of the relationships of exposures to both contaminant pathways and doses. Besides fulfilling the primary NHEXAS objectives, the NHEXAS data provided an opportunity to explore secondary usages, such as examining pathway to route of exposure relationships. A generic type of structural equation model was used to define the anticipated relationships among the various data types for both arsenic (As) and lead (Pb). Since, by design, only a few participants provided data for all sample types, implementing this model required that some media concentrations (outdoor air and soil) be imputed for subjects with missing information by using measurements collected in the same geographic area and time period. The model, and associated pairwise correlations, generally revealed significant but weak associations among the concentrations, exposures, and doses; the strongest associations occurred for the various air measurements (indoor versus outdoor and personal). The generally weak associations were thought to be partly due to the absence of complete coverage of nonresidential environmental media and to nonsynchronization of relevant measurement times and integration periods of collection across the various sample types. In general, relationships between the NHEXAS questionnaire data and the various concentration, exposure, and body-burden measures were also weak. The model results and the modeling exercise suggest several ways for optimizing the design of future exposure assessment studies that are aimed at supporting structural modeling activities.

  10. Conceptual model for assessment of inhalation exposure: defining modifying factors.

    PubMed

    Tielemans, Erik; Schneider, Thomas; Goede, Henk; Tischer, Martin; Warren, Nick; Kromhout, Hans; Van Tongeren, Martie; Van Hemmen, Joop; Cherrie, John W

    2008-10-01

    The present paper proposes a source-receptor model to schematically describe inhalation exposure to help understand the complex processes leading to inhalation of hazardous substances. The model considers a stepwise transfer of a contaminant from the source to the receptor. The conceptual model is constructed using three components, i.e. (i) the source, (ii) various transmission compartments and (iii) the receptor, and describes the contaminant's emission and its pattern of transport. Based on this conceptual model, a list of nine mutually independent principal modifying factors (MFs) is proposed: activity emission potential, substance emission potential, localized control, separation, segregation, dilution, worker behavior, surface contamination and respiratory protection. These MFs describe the exposure process at a high level of abstraction so that the model can be generically applicable. A list of exposure determinants underlying each of these principal MFs is proposed to describe the exposure process at a more detailed level. The presented conceptual model is developed in conjunction with an activity taxonomy as described in a separate paper. The proposed conceptual model and MFs should be seen as 'building blocks' for development of higher tier exposure models.

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

    PubMed

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

    2012-03-01

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

  12. A proposed framework for assessing risk from less-than-lifetime exposures to carcinogens.

    PubMed

    Felter, Susan P; Conolly, Rory B; Bercu, Joel P; Bolger, P Michael; Boobis, Alan R; Bos, Peter M J; Carthew, Philip; Doerrer, Nancy G; Goodman, Jay I; Harrouk, Wafa A; Kirkland, David J; Lau, Serrine S; Llewellyn, G Craig; Preston, R Julian; Schoeny, Rita; Schnatter, A Robert; Tritscher, Angelika; van Velsen, Frans; Williams, Gary M

    2011-07-01

    Quantitative methods for estimation of cancer risk have been developed for daily, lifetime human exposures. There are a variety of studies or methodologies available to address less-than-lifetime exposures. However, a common framework for evaluating risk from less-than-lifetime exposures (including short-term and/or intermittent exposures) does not exist, which could result in inconsistencies in risk assessment practice. To address this risk assessment need, a committee of the International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute conducted a multisector workshop in late 2009 to discuss available literature, different methodologies, and a proposed framework. The proposed framework provides a decision tree and guidance for cancer risk assessments for less-than-lifetime exposures based on current knowledge of mode of action and dose-response. Available data from rodent studies and epidemiological studies involving less-than-lifetime exposures are considered, in addition to statistical approaches described in the literature for evaluating the impact of changing the dose rate and exposure duration for exposure to carcinogens. The decision tree also provides for scenarios in which an assumption of potential carcinogenicity is appropriate (e.g., based on structural alerts or genotoxicity data), but bioassay or other data are lacking from which a chemical-specific cancer potency can be determined. This paper presents an overview of the rationale for the workshop, reviews historical background, describes the proposed framework for assessing less-than-lifetime exposures to potential human carcinogens, and suggests next steps.

  13. Study Protocol - Accurate assessment of kidney function in Indigenous Australians: aims and methods of the eGFR Study

    PubMed Central

    2010-01-01

    Background There is an overwhelming burden of cardiovascular disease, type 2 diabetes and chronic kidney disease among Indigenous Australians. In this high risk population, it is vital that we are able to measure accurately kidney function. Glomerular filtration rate is the best overall marker of kidney function. However, differences in body build and body composition between Indigenous and non-Indigenous Australians suggest that creatinine-based estimates of glomerular filtration rate derived for European populations may not be appropriate for Indigenous Australians. The burden of kidney disease is borne disproportionately by Indigenous Australians in central and northern Australia, and there is significant heterogeneity in body build and composition within and amongst these groups. This heterogeneity might differentially affect the accuracy of estimation of glomerular filtration rate between different Indigenous groups. By assessing kidney function in Indigenous Australians from Northern Queensland, Northern Territory and Western Australia, we aim to determine a validated and practical measure of glomerular filtration rate suitable for use in all Indigenous Australians. Methods/Design A cross-sectional study of Indigenous Australian adults (target n = 600, 50% male) across 4 sites: Top End, Northern Territory; Central Australia; Far North Queensland and Western Australia. The reference measure of glomerular filtration rate was the plasma disappearance rate of iohexol over 4 hours. We will compare the accuracy of the following glomerular filtration rate measures with the reference measure: Modification of Diet in Renal Disease 4-variable formula, Chronic Kidney Disease Epidemiology Collaboration equation, Cockcroft-Gault formula and cystatin C- derived estimates. Detailed assessment of body build and composition was performed using anthropometric measurements, skinfold thicknesses, bioelectrical impedance and a sub-study used dual-energy X-ray absorptiometry. A

  14. Personal exposure assessment to particulate metals using a paper-based analytical device

    NASA Astrophysics Data System (ADS)

    Cate, David; Volckens, John; Henry, Charles

    2013-03-01

    The development of a paper-based analytical device (PAD) for assessing personal exposure to particulate metals will be presented. Human exposure to metal aerosols, such as those that occur in the mining, construction, and manufacturing industries, has a significant impact on the health of our workforce, costing an estimated $10B in the U.S and causing approximately 425,000 premature deaths world-wide each year. Occupational exposure to particulate metals affects millions of individuals in manufacturing, construction (welding, cutting, blasting), and transportation (combustion, utility maintenance, and repair services) industries. Despite these effects, individual workers are rarely assessed for their exposure to particulate metals, due mainly to the high cost and effort associated with personal exposure measurement. Current exposure assessment methods for particulate metals call for an 8-hour filter sample, after which time, the filter sample is transported to a laboratory and analyzed by inductively-coupled plasma (ICP). The time from sample collection to reporting is typically weeks and costs several hundred dollars per sample. To exacerbate the issue, method detection limits suffer because of sample dilution during digestion. The lack of sensitivity hampers task-based exposure assessment, for which sampling times may be tens of minutes. To address these problems, and as a first step towards using microfluidics for personal exposure assessment, we have developed PADs for measurement of Pb, Cd, Cr, Fe, Ni, and Cu in aerosolized particulate matter.

  15. A pragmatic approach to assess the exposure of the honey bee (Apis mellifera) when subjected to pesticide spray.

    PubMed

    Poquet, Yannick; Bodin, Laurent; Tchamitchian, Marc; Fusellier, Marion; Giroud, Barbara; Lafay, Florent; Buleté, Audrey; Tchamitchian, Sylvie; Cousin, Marianne; Pélissier, Michel; Brunet, Jean-Luc; Belzunces, Luc P

    2014-01-01

    Plant protection spray treatments may expose non-target organisms to pesticides. In the pesticide registration procedure, the honey bee represents one of the non-target model species for which the risk posed by pesticides must be assessed on the basis of the hazard quotient (HQ). The HQ is defined as the ratio between environmental exposure and toxicity. For the honey bee, the HQ calculation is not consistent because it corresponds to the ratio between the pesticide field rate (in mass of pesticide/ha) and LD50 (in mass of pesticide/bee). Thus, in contrast to all other species, the HQ can only be interpreted empirically because it corresponds to a number of bees/ha. This type of HQ calculation is due to the difficulty in transforming pesticide field rates into doses to which bees are exposed. In this study, we used a pragmatic approach to determine the apparent exposure surface area of honey bees submitted to pesticide treatments by spraying with a Potter-type tower. The doses received by the bees were quantified by very efficient chemical analyses, which enabled us to determine an apparent surface area of 1.05 cm(2)/bee. The apparent surface area was used to calculate the exposure levels of bees submitted to pesticide sprays and then to revisit the HQ ratios with a calculation mode similar to that used for all other living species. X-tomography was used to assess the physical surface area of a bee, which was 3.27 cm(2)/bee, and showed that the apparent exposure surface was not overestimated. The control experiments showed that the toxicity induced by doses calculated with the exposure surface area was similar to that induced by treatments according to the European testing procedure. This new approach to measure risk is more accurate and could become a tool to aid the decision-making process in the risk assessment of pesticides.

  16. [The key problems in the population exposure assessment of hazardous chemicals accidents].

    PubMed

    Pan, L J; Liu, F P; Zhang, X; Bai, X T; Shi, X M

    2016-07-06

    Serious accidents of hazardous chemicals can cause a variety of acute or chronic impairment in human health. The effects of hazardous chemicals on human health can be identified by carrying on population exposure assessment. Through analyzing the domestic and overseas population exposure assessment cases related to hazardous chemicals accidents, we summarized that the base and key of the population exposure assessment were to identify the characteristics of the chemicals , delimit the area and the population exposed to the chemicals, and collect the data of the monitored chemicals and the population health in the polluted area.

  17. Human Health Exposure Assessment for Rocky Mountain Arsenal Study Area Evaluations. Volume 6-F. Eastern Study Area Exposure Assessment. Version 4.1

    DTIC Science & Technology

    1990-09-01

    TECHNICAL SUPPORT FOR i ROCKY MOUNTAIN ARSENAL AD-A279 051 Accesion For NTIS CRA&I FINAL DTIC TAB HUMAN HEALTH EXPOSURE ASSESSMENT Unannouncedor& FOR...INCORPORATED Applied Environmental , Inc. CH2M HILLnc DTICDataChem, In . • E LECT E R.L. Stollar and Associates ECTE194Y1019i - Prepared for: U.S...CODE APPROVED FOR PUBLIC RELEASE; DISTRIBUTION IS UNLIMITED 13. ABS CT xm m20word TVE OF THE HUMAN HEALTH EXPOSURE ASSESSMENT INCLUDE: 1. ESTIMATE

  18. A review of traffic-related air pollution exposure assessment studies in the developing world.

    PubMed

    Han, Xianglu; Naeher, Luke P

    2006-01-01

    Exposure assessment studies in the developing world are important. Although recent years have seen an increasing number of traffic-related pollution exposure studies, exposure assessment data on this topic are still limited. Differences among measuring methods and a lack of strict quality control in carrying out exposure assessment make it difficult to generalize and compare findings between studies. In this article, exposure assessment studies carried out in the developing world on several traffic-related air pollutants are reviewed. These pollutants include particulate matter (PM), carbon monoxide (CO), nitrogen dioxide (NO(2)), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). In addition, it discusses advantages and disadvantages of various monitoring methods (ambient fixed-site monitoring, microenvironment monitoring, and personal exposure assessment using portable samplers) for these pollutants in exposure assessment studies. Also included in this paper is a brief introduction of standards for these pollutants in ambient air or in occupational settings established by the United States Environmental Protection Agency (USEPA), the United States Occupational Safety and Health Administration (OSHA) and the World Health Organization (WHO). The review ends with a summary of the limitations and gaps in recent studies and suggestions for future research in the developing world.

  19. Estimation of Apple Intake for the Exposure Assessment of Residual Chemicals Using Korea National Health and Nutrition Examination Survey Database

    PubMed Central

    2016-01-01

    The aims of this study were to develop strategies and algorithms of calculating food commodity intake suitable for exposure assessment of residual chemicals by using the food intake database of Korea National Health and Nutrition Examination Survey (KNHANES). In this study, apples and their processed food products were chosen as a model food for accurate calculation of food commodity intakes uthrough the recently developed Korea food commodity intake calculation (KFCIC) software. The average daily intakes of total apples in Korea Health Statistics were 29.60 g in 2008, 32.40 g in 2009, 34.30 g in 2010, 28.10 g in 2011, and 24.60 g in 2012. The average daily intakes of apples by KFCIC software was 2.65 g higher than that by Korea Health Statistics. The food intake data in Korea Health Statistics might have less reflected the intake of apples from mixed and processed foods than KFCIC software has. These results can affect outcome of risk assessment for residual chemicals in foods. Therefore, the accurate estimation of the average daily intake of food commodities is very important, and more data for food intakes and recipes have to be applied to improve the quality of data. Nevertheless, this study can contribute to the predictive estimation of exposure to possible residual chemicals and subsequent analysis for their potential risks. PMID:27152299

  20. Estimation of Apple Intake for the Exposure Assessment of Residual Chemicals Using Korea National Health and Nutrition Examination Survey Database.

    PubMed

    Kim, Bumsik; Baek, Min-Seok; Lee, Yongmin; Paik, Jean Kyung; Chang, Moon-Ik; Rhee, Gyu-Seek; Ko, Sanghoon

    2016-04-01

    The aims of this study were to develop strategies and algorithms of calculating food commodity intake suitable for exposure assessment of residual chemicals by using the food intake database of Korea National Health and Nutrition Examination Survey (KNHANES). In this study, apples and their processed food products were chosen as a model food for accurate calculation of food commodity intakes uthrough the recently developed Korea food commodity intake calculation (KFCIC) software. The average daily intakes of total apples in Korea Health Statistics were 29.60 g in 2008, 32.40 g in 2009, 34.30 g in 2010, 28.10 g in 2011, and 24.60 g in 2012. The average daily intakes of apples by KFCIC software was 2.65 g higher than that by Korea Health Statistics. The food intake data in Korea Health Statistics might have less reflected the intake of apples from mixed and processed foods than KFCIC software has. These results can affect outcome of risk assessment for residual chemicals in foods. Therefore, the accurate estimation of the average daily intake of food commodities is very important, and more data for food intakes and recipes have to be applied to improve the quality of data. Nevertheless, this study can contribute to the predictive estimation of exposure to possible residual chemicals and subsequent analysis for their potential risks.

  1. Distinguishing nanomaterial particles from background airborne particulate matter for quantitative exposure assessment

    NASA Astrophysics Data System (ADS)

    Ono-Ogasawara, Mariko; Serita, Fumio; Takaya, Mitsutoshi

    2009-10-01

    As the production of engineered nanomaterials quantitatively expands, the chance that workers involved in the manufacturing process will be exposed to nanoparticles also increases. A risk management system is needed for workplaces in the nanomaterial industry based on the precautionary principle. One of the problems in the risk management system is difficulty of exposure assessment. In this article, examples of exposure assessment in nanomaterial industries are reviewed with a focus on distinguishing engineered nanomaterial particles from background nanoparticles in workplace atmosphere. An approach by JNIOSH (Japan National Institute of Occupational Safety and Health) to quantitatively measure exposure to carbonaceous nanomaterials is also introduced. In addition to real-time measurements and qualitative analysis by electron microscopy, quantitative chemical analysis is necessary for quantitatively assessing exposure to nanomaterials. Chemical analysis is suitable for quantitative exposure measurement especially at facilities with high levels of background NPs.

  2. Assessing elemental mercury vapor exposure from cultural and religious practices.

    PubMed Central

    Riley, D M; Newby, C A; Leal-Almeraz, T O; Thomas, V M

    2001-01-01

    Use of elemental mercury in certain cultural and religious practices can cause high exposures to mercury vapor. Uses include sprinkling mercury on the floor of a home or car, burning it in a candle, and mixing it with perfume. Some uses can produce indoor air mercury concentrations one or two orders of magnitude above occupational exposure limits. Exposures resulting from other uses, such as infrequent use of a small bead of mercury, could be well below currently recognized risk levels. Metallic mercury is available at almost all of the 15 botanicas visited in New York, New Jersey, and Pennsylvania, but botanica personnel often deny having mercury for sale when approached by outsiders to these religious and cultural traditions. Actions by public health authorities have driven the mercury trade underground in some locations. Interviews indicate that mercury users are aware that mercury is hazardous, but are not aware of the inhalation exposure risk. We argue against a crackdown by health authorities because it could drive the practices further underground, because high-risk practices may be rare, and because uninformed government intervention could have unfortunate political and civic side effects for some Caribbean and Latin American immigrant groups. We recommend an outreach and education program involving religious and community leaders, botanica personnel, and other mercury users. PMID:11564612

  3. DEVELOPMENT OF DNA MICROARRAYS FOR ECOLOGICAL EXPOSURE ASSESSMENT

    EPA Science Inventory

    EPA/ORD is moving forward with a computational toxicology initiative in FY 04 which aims to integrate genomics and computational methods to provide a mechanistic basis for prediction of exposure and effects of chemical stressors in the environment.

    The goal of the presen...

  4. Environmental Tobacco Smoke: Measuring Exposures and Assessing Health Effects.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC.

    This book evaluates methodologies in epidemiologic and related studies for obtaining measurements of exposure to environmental tobacco smoke (ETS). The book is divided into three parts. The first part discusses physicochemical and toxicological studies of environmental tobacco smoke, including physicochemical nature of smoke and in vivo and in…

  5. Environmental chemical mixtures: Assessing ecological exposure and effects in streams

    EPA Science Inventory

    This product is a USGS fact sheet that describes a collaborative effort between USGS and US EPA to characterize exposures to chemical mixtures and associated biological effects for a diverse range of US streams representing varying watershed size, land-use patterns, and ecotypes.

  6. Assessment of potential asbestos exposures from jet engine overhaul work.

    PubMed

    Mlynarek, S P; Van Orden, D R

    2012-06-01

    Asbestos fibers have been used in a wide variety of products and numerous studies have shown that exposures from the use or manipulation of these products can vary widely. Jet engines contained various components (gaskets, clamps, o-rings and insulation) that contained asbestos that potentially could release airborne fibers during routine maintenance or during an engine overhaul. To evaluate the potential exposures to aircraft mechanics, a Pratt & Whitney JT3D jet engine was obtained and overhauled by experienced mechanics using tools and work practices similar to those used since the time this engine was manufactured. This study has demonstrated that the disturbance of asbestos-containing gaskets, o-rings, and other types of asbestos-containing components, while performing overhaul work to a jet engine produces very few airborne fibers, and that virtually none of these aerosolized fibers is asbestos. The overhaul work was observed to be dirty and oily. The exposures to the mechanics and bystanders were several orders of magnitude below OSHA exposure regulations, both current and historic. The data presented underscore the lack of risk to the health of persons conducting this work and to other persons in proximity to it from airborne asbestos.

  7. HESI EXPOSURE FACTORS DATABASE FOR AGGREGATE AND CUMULATIVE RISK ASSESSMENT

    EPA Science Inventory

    In recent years, the risk analysis community has broadened its use of complex aggregate and cumulative residential exposure models (e.g., to meet the requirements of the 1996 Food Quality Protection Act). The value of these models is their ability to incorporate a range of inp...

  8. How EPA Uses Dietary data from USDA for Exposure Assessments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: To present the procedures the US Environmental Protection Agency’s (EPA’s) Office of Pesticide Programs (OPP) uses to update the estimates of dietary exposure to pesticides using the consumption data from the National Health and Nutrition Survey, What We Eat in America and methodology a...

  9. Assessing elemental mercury vapor exposure from cultural and religious practices.

    PubMed

    Riley, D M; Newby, C A; Leal-Almeraz, T O; Thomas, V M

    2001-08-01

    Use of elemental mercury in certain cultural and religious practices can cause high exposures to mercury vapor. Uses include sprinkling mercury on the floor of a home or car, burning it in a candle, and mixing it with perfume. Some uses can produce indoor air mercury concentrations one or two orders of magnitude above occupational exposure limits. Exposures resulting from other uses, such as infrequent use of a small bead of mercury, could be well below currently recognized risk levels. Metallic mercury is available at almost all of the 15 botanicas visited in New York, New Jersey, and Pennsylvania, but botanica personnel often deny having mercury for sale when approached by outsiders to these religious and cultural traditions. Actions by public health authorities have driven the mercury trade underground in some locations. Interviews indicate that mercury users are aware that mercury is hazardous, but are not aware of the inhalation exposure risk. We argue against a crackdown by health authorities because it could drive the practices further underground, because high-risk practices may be rare, and because uninformed government intervention could have unfortunate political and civic side effects for some Caribbean and Latin American immigrant groups. We recommend an outreach and education program involving religious and community leaders, botanica personnel, and other mercury users.

  10. Radio frequency exposure in mobile phone users: implications for exposure assessment in epidemiological studies.

    PubMed

    Morrissey, Joseph J

    2007-01-01

    The majority of epidemiological studies investigating correlations between long-term low-level radiofrequency (RF) exposure from mobile phones and health endpoints have followed a case-control design, requiring reconstruction of individual RF exposure. To date, these have employed 'time of use' as an exposure surrogate from questionnaire information or billing records. The present study demonstrates such an approach may not account for variability in mobile phone transmit power, which can be roughly correlated with RF exposure. This variability exists (a) during a single call, (b) between separate calls, (c) between averaged values from individuals within a local study group and (d) between average values from groups in different geographical locations. The present data also suggest an age-related influence on talk time, as well as significant inaccuracy (45-60%) in recalling 'time of use'. Evolving technology and changing use behaviours may add additional complexities. Collectively, these data suggest efforts to identify dose response and statistical correlations between mobile phone use and subtle health endpoints may be significantly challenged.

  11. Progress in High Throughput Exposure Assessment for Prioritizing Human Exposure to Environmental Chemicals (SRA)

    EPA Science Inventory

    For thousands of chemicals in commerce, there is little or no information about exposure or health and ecological effects. The US Environmental Protection Agency (USEPA) has ongoing research programs to develop and evaluate models that use the often minimal chemical information a...

  12. UC-123 Agent Orange Exposure Assessment, Post-Vietnam (1972-1982)

    DTIC Science & Technology

    2012-04-27

    Consultative Letter 3. DATES COVERED (From – To) Nov 2011 – Mar 2012 4. TITLE AND SUBTITLE UC-123 Agent Orange Exposure Assessment, Post-Vietnam...88ABW-2012-2550, 27 Apr 2012 13. SUPPLEMENTARY NOTES 14. ABSTRACT We attempted to quantify potential individual exposures to Agent Orange ...characteristics of dried Agent Orange residue, and the conditions of general exposure. At this time, we conclude that the discernable information suggests

  13. Aflatoxin levels and exposure assessment of Spanish infant cereals.

    PubMed

    Hernández-Martínez, Raquel; Navarro-Blasco, Iñigo

    2010-01-01

    Aflatoxins (AFB1, AFB2, AFG1 and AFG2) are immunosuppressant, mutagenic, teratogenic and carcinogenic agents with a widespread presence in foodstuffs. Since human exposure to aflatoxins occurs primarily by contaminated food intake, and given the greater susceptibility of infants to their adverse effects, the quantification of these mycotoxins in infant food based on cereals is of relevance. Aflatoxin levels were determined in 91 Spanish infant cereals classified in terms of non- and organically produced and several types from 10 different manufacturers, using a extraction procedure followed by inmunoaffinity column clean-up step and HPLC with fluorescence detection (FLD) and post-column derivatisation (Kobra Cell system). Daily aflatoxin intake was also assessed. Preliminary analysis showed a valuable incidence of detected infant cereal samples at an upper concentration level than the detection limit for total aflatoxin (66%), corresponding to a 46, 40, 34 and 11% for AFB1, AFB2, AFG1 and AFG2, respectively. Lower aflatoxin values (median, Q1, Q3) in conventional infant cereal (n = 74, AFB1:

  14. Assessment of exposure in epidemiological studies: the example of silica dust.

    PubMed

    Dahmann, Dirk; Taeger, Dirk; Kappler, Martin; Büchte, Sebastian; Morfeld, Peter; Brüning, Thomas; Pesch, Beate

    2008-09-01

    Exposure to crystalline silica ranks among the most frequent occupational exposures to an established human carcinogen. Health-based occupational exposure limits can only be derived from a reliable dose-response relationship. Although quartz dust seems to be a well-measurable agent, several uncertainties in the quantification of exposure to crystalline silica can bias the risk estimates in epidemiological studies. This review describes the silica-specific methodological issues in the assessment of exposure. The mineralogical forms of silica, the technologies applied to generate dust, protective measures, and co-existing carcinogens are important parameters to characterize the exposure condition of an occupational setting. Another methodological question concerns the measurement of the respirable dust fraction in the worker's breathing zone and the determination of the quartz content in that fraction. Personal devices have been increasingly employed over time, whereas norms for the measurement of respirable dust have been defined only recently. Several methods are available to analyse the content of crystalline silica in dust with limits of quantitation close to environmental exposure levels. For epidemiological studies, the quartz content has frequently not been measured but only calculated. To develop a silica-dust database for epidemiological purposes, historical dust concentrations sampled with different devices and measured as particle numbers have to be converted in a common exposure metric. For the development of a job-exposure matrix (JEM), missing historical data have to be estimated to complete the database over time. Unknown but frequently high-exposure levels of the past contribute largely to the cumulative exposure of a worker. Because the establishment of a JEM is crucial for risk estimates, sufficient information should be made accessible to allow an estimation of the uncertainties in the assessment of exposure to crystalline silica. The impressive

  15. A probabilistic assessment of health risks associated with short-term exposure to tropospheric ozone

    SciTech Connect

    Whitfield, R.G; Biller, W.F.; Jusko, M.J.; Keisler, J.M.

    1996-06-01

    The work described in this report is part of a larger risk assessment sponsored by the U.S. Environmental Protection Agency. Earlier efforts developed exposure-response relationships for acute health effects among populations engaged in heavy exertion. Those efforts also developed a probabilistic national ambient air quality standards exposure model and a general methodology for integrating probabilistic exposure-response relation- ships and exposure estimates to calculate overall risk results. Recently published data make it possible to model additional health endpoints (for exposure at moderate exertion), including hospital admissions. New air quality and exposure estimates for alternative national ambient air quality standards for ozone are combined with exposure-response models to produce the risk results for hospital admissions and acute health effects. Sample results explain the methodology and introduce risk output formats.

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

    SciTech Connect

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

    2008-12-21

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

  17. Assessing frost damages using dynamic models in walnut trees: exposure rather than vulnerability controls frost risks.

    PubMed

    Charrier, Guillaume; Chuine, Isabelle; Bonhomme, Marc; Améglio, Thierry

    2017-02-09

    Frost damages develop when exposure overtakes frost vulnerability. Frost risk assessment therefore needs dynamic simulation of frost hardiness using temperature and photoperiod in interaction with developmental stage. Two models, including or not the effect of photoperiod were calibrated using five years of frost hardiness monitoring (2007-2012), in two locations (low and high elevation) for three walnut genotypes with contrasted phenology and maximum hardiness (Juglans regia cv Franquette, Juglans regia x nigra 'Early' and 'Late'). The Photothermal model predicted more accurate values for all genotypes (Efficiency = 0.879; RMSEP = 2.55 °C) than the Thermal model (Efficiency = 0.801; RMSEP = 3.24 °C). Predicted frost damages were strongly correlated to minimum temperature of the freezing events (ρ = -0.983) rather than actual frost hardiness (ρ = -0.515), or ratio of phenological stage completion (ρ = 0.336). Higher frost risks are consequently predicted during winter, at high elevation, whereas spring is only risky at low elevation in early genotypes exhibiting faster dehardening rate. However, early frost damages, although of lower value, may negatively affect fruit production the subsequent year (R(2)  = 0.381, P = 0.057). These results highlight the interacting pattern between frost exposure and vulnerability at different scales and the necessity of intra-organ studies to understand the time course of frost vulnerability in flower buds along the winter.

  18. Probabilistic assessment of exposure to hair cosmetic products by the French population.

    PubMed

    Ficheux, A S; Bernard, A; Chevillotte, G; Dornic, N; Roudot, A C

    2016-06-01

    Cosmetic exposure data are limited in Europe and especially in France. The aim of this study was to assess the exposure to hair cosmetics using recent consumption data (percentage of users, frequency of use and amount per use) generated for the French population (Ficheux et al., 2015, 2016). Exposure was assessed using a probabilistic method for eleven hair products: liquid shampoo, dry shampoo, conditioner, hair mask, hair serum, hair oil, styling lacquer, styling gel, styling foam, styling wax and styling spray. Exposure was assessed by sex and by age classes in adults and children. Pregnant women were also studied. For liquid shampoo, conditioner and some styling products (gel, lacquer and foam), the levels of exposure were higher than the values currently used by the Scientific Committee on Consumer Safety (SCCS). Exposure values found for styling wax and styling spray were lower than SCCS values. Exposure was assessed for the first time for dry shampoo, hair mask, hair serum and hair oil products. These new French exposure values will be useful for safety assessors and for safety agencies in order to protect the general population and these at-risk populations.

  19. STRATEGIC PLAN FOR THE ANALYSIS OF THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) PILOT STUDY DATA

    EPA Science Inventory

    The Office of Research and Development (ORD) of the U.S. Environmental Protection Agency (EPA) initiated the National Human Exposure Assessment Survey (NHEXAS) in the early 1990's. It was a population-based pilot study of the exposure of over 500 people in three areas of the U....

  20. Elemental Speciation as an Essential Part of Formulating Exposure Assessments that Support Risk Estimates

    EPA Science Inventory

    The chemical form specific toxicity of arsenic has caused scientists to move toward species specific assessments with an emphasis on biological relevance of an exposure. For example, numerous studies on the occurrence of arsenic in rice have documented the exposure potential fro...

  1. Full Mission Astronaut Radiation Exposure Assessments for Long Duration Lunar Surface Missions

    NASA Technical Reports Server (NTRS)

    Adamczyk, Anne; Clowdsley, Martha; Qualls, Garry; Blattnig, Steve; Lee, Kerry; Fry, Dan; Stoffle, Nicholas; Simonsen, Lisa; Slaba, Tony; Walker, Steven; Zapp, Edward

    2011-01-01

    Risk to astronauts due to ionizing radiation exposure is a primary concern for missions beyond Low Earth Orbit (LEO) and will drive mission architecture requirements, mission timelines, and operational practices. For short missions, radiation risk is dominated by the possibility of a large Solar Particle Event (SPE). Longer duration missions have both SPE and Galactic Cosmic Ray (GCR) risks. SPE exposure can contribute significantly toward cancer induction in combination with GCR. As mission duration increases, mitigation strategies must address the combined risks from SPE and GCR exposure. In this paper, full mission exposure assessments were performed for the proposed long duration lunar surface mission scenarios. In order to accomplish these assessments, previously developed radiation shielding models for a proposed lunar habitat and rover were utilized. End-to-End mission exposure assessments were performed by first calculating exposure rates for locations in the habitat, rover, and during Extra-Vehicular Activities (EVA). Subsequently, total mission exposures were evaluated for the proposed timelines. Mission exposure results, assessed in terms of effective dose, are presented for the proposed timelines and recommendations are made for improved astronaut shielding and safer operational practices.

  2. RESPIRATORY DOSE TO SUSCEPTIBLE POPULATIONS ASSESSED BY EXPOSURE AND DOSIMETRY STUDIES

    EPA Science Inventory

    Respiratory Dose to Susceptible Populations Assessed by Exposure and Dosimetry Studies

    Chong Kim1 and Ronald Williams2, 1USEPA National Health and Environmental Effects Research Laboratory and 2USEPA National Exposure Research Laboratory, RTP, NC.

    Rationale: Parti...

  3. An Exploratory Study: Assessment of Modeled Dioxin Exposure in Ceramic Art Studios (Final Report, 2008)

    EPA Science Inventory

    EPA announced the availability of the final report, An Exploratory Study: Assessment of Modeled Dioxin Exposure in Ceramic Art Studios. This report investigates the potential dioxin exposure to artists/hobbyists who use ball clay to make pottery and related products. Derm...

  4. EXPOSURE ASSESSMENT TO DIOXINS FROM THE USE OF TAMPONS AND DIAPERS

    EPA Science Inventory

    Exposure Assessment to Dioxins from the Use of Tampons and Diapers
    Michael J. DeVito and Arnold Schecter
    Abstract
    Methods: Four brands of tampons and four brands of infant diapers were analyzed for dioxin concentrations. Exposures to dioxins were modeled using parti...

  5. A Framework for Assessing Health Risk of Environmental Exposures to Children (Final)

    EPA Science Inventory

    EPA released the final report entitled, A Framework for Assessing Health Risk of Environmental Exposures to Children, which examines the impact of potential exposures during developmental lifestages and subsequent lifestages, while emphasizing the iterative nature of the a...

  6. A National Assessment of Sea Level Rise Exposure Using Lidar Elevation Data

    NASA Astrophysics Data System (ADS)

    Strauss, B.; Kulp, S. A.; Tebaldi, C.

    2014-12-01

    The Third National Climate Assessment addressed sea level rise and aggravated coastal flood exposure in all regions, but was completed before high quality lidar-based elevation data became available throughout the entire coastal United States (excluding Alaska). Here we present what we believe to be the first full national assessment incorporating these data. The assessment includes tabulation of land less than 1-6 m above the local high tide line, and of a wide range of features sitting on that land, including total population, socially vulnerable population, housing, property value, road miles, power plants, schools, hospitals, and a wide range of other infrastructure and critical facilities, as well as EPA-listed facilities that are potential sources of contamination during floods or permanent inundation. Tabulations span from zip code to national levels. Notable patterns include the strong concentration of exposure across multiple scales, with a small number of states accounting for most of the total national exposure; and a small number of zip codes accounting for a large proportion of the exposure within many states. Additionally, different features show different exposure patterns; in one example, land and road miles have relatively high exposure but population and property have relatively low exposure in North Carolina. The assessment further places this exposure analysis in the context of localized sea level rise projections integrated with coastal flood risk.

  7. Assessment of Secondhand Smoke Exposure at School among U.S. Middle and High School Students

    ERIC Educational Resources Information Center

    Olufajo, Olubode Ademola; Agaku, Israel Terungwa

    2015-01-01

    To obtain nationally representative estimates of the prevalence of secondhand smoke (SHS) exposure at U.S. schools, we assessed the prevalence and correlates of SHS exposure at school among U.S. middle and high school students using data from the 2011 National Youth Tobacco Survey comprising of 18,866 students spread across all the U.S. states.…

  8. Enhancing Air Pollution Exposure Assessment in the 21st Century by Measurement and Modeling

    EPA Science Inventory

    Exposure assessments may be conducted using measurement data, modeling results, or through a combination of measurements and models. Models are required to estimate exposure when measurement data is insufficient due to spatial or temporal gaps (e.g., for refined local scale asses...

  9. THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) STUDY IN ARIZONA-INTRODUCTION AND PRELIMINARY RESULTS

    EPA Science Inventory

    The objective of the National Human Exposure Assessment Survey (NHEXAS) in Arizona is to determine the multimedia distribution of total human exposure to environmental pollutants in the classes of metals, pesticides, and volatile organic compounds (VOCs) for the population of Ari...

  10. Instruments to assess and measure personal and environmental radiofrequency-electromagnetic field exposures.

    PubMed

    Bhatt, Chhavi Raj; Redmayne, Mary; Abramson, Michael J; Benke, Geza

    2016-03-01

    Radiofrequency-electromagnetic field (RF-EMF) exposure of human populations is increasing due to the widespread use of mobile phones and other telecommunication and broadcasting technologies. There are ongoing concerns about potential short- and long-term public health consequences from RF-EMF exposures. To elucidate the RF-EMF exposure-effect relationships, an objective evaluation of the exposures with robust assessment tools is necessary. This review discusses and compares currently available RF-EMF exposure assessment instruments, which can be used in human epidemiological studies. Quantitative assessment instruments are either mobile phone-based (apps/software-modified and hardware-modified) or exposimeters. Each of these tool has its usefulness and limitations. Our review suggests that assessment of RF-EMF exposures can be improved by using these tools compared to the proxy measures of exposure (e.g. questionnaires and billing records). This in turn, could be used to help increase knowledge about RF-EMF exposure induced health effects in human populations.

  11. Refinement of the Nanoparticle Emission Assessment Technique into the Nanomaterial Exposure Assessment Technique (NEAT 2.0)

    PubMed Central

    Eastlake, Adrienne C; Beaucham, Catherine; Martinez, Kenneth F; Dahm, Matthew M; Sparks, Christopher; Hodson, Laura L; Geraci, Charles L

    2016-01-01

    Engineered nanomaterial emission and exposure characterization studies have been completed at more than 60 different facilities by the National Institute for Occupational Safety and Health (NIOSH). These experiences have provided NIOSH the opportunity to refine an earlier published technique, the Nanoparticle Emission Assessment Technique (NEAT 1.0), into a more comprehensive technique for assessing worker and workplace exposures to engineered nanomaterials. This change is reflected in the new name Nanomaterial Exposure Assessment Technique (NEAT 2.0) which distinguishes it from NEAT 1.0. NEAT 2.0 places a stronger emphasis on time-integrated, filter-based sampling (i.e., elemental mass analysis and particle morphology) in the worker's breathing zone (full shift and task specific) and area samples to develop job exposure matrices. NEAT 2.0 includes a comprehensive assessment of emissions at processes and job tasks, using direct-reading instruments (i.e., particle counters) in data-logging mode to better understand peak emission periods. Evaluation of worker practices, ventilation efficacy, and other engineering exposure control systems and risk management strategies serve to allow for a comprehensive exposure assessment. PMID:27027845

  12. REACH exposure assessment of anticorrosive paint products--determination of exposure from application and service life to the aquatic environment.

    PubMed

    Gade, Anne Lill; Heiaas, Harald; Thomas, Kevin; Hylland, Ketil

    2011-12-01

    The European Community Regulation on the registration, evaluation, authorisation and restriction of chemicals (REACH) introduced exposure scenarios describing safe use quantitatively, and enhancing the importance of scientific based exposure assessments. This paper presents methods to determine exposure from the airless spray application of anti-corrosive paint and leaching of painted articles submerged in seawater, to establish whether it is possible to test these exposures in a reproducible and feasible way. The paper also presents results from using the methods in order to assess how well the default values recommended under REACH coincide with the tested values and corresponding values available in literature. The methods used were feasible under laboratory conditions. The reproducibility of the application study was shown to be good and all analyses of the leaching showed concentrations below detection limit. More replicates will be required to validate the reproducibility of the growth inhibition tests. Measured values for the present overspray scenario were between, and the leaching values below, values from REACH guidelines and emission scenario documents. Further development of the methods is recommended.

  13. [Exposure to VHF and UHF electromagnetic fields among workers employed in radio and TV broadcast centers. I. Assessment of exposure].

    PubMed

    Zmyślony, M; Aniołczyk, H; Bortkiewicz, A

    2001-01-01

    Nowadays, radio and television have become one of the areas of the human technical activity that develops most rapidly. Also ultra-short waves of VHF (30-300 MHz) and UHF (0.3-3 GHz) bands have proved to be the most important carriers of radio and TV-programs. In Poland, a network of radio and TV broadcast centers (RTCN) with high (over 200 m) masts was set up in the 1960s and 1970s. These centers concentrate the majority of stations broadcasting national and local programs (for areas within the RTCN range). At present, the RTCN established several decades ago are equally important. The assessment of the exposure to electromagnetic fields among workers of multi-program broadcast stations is complicated and feasible only to a certain degree of approximation because of changing conditions of exposure in individual stations during their long history, resulting from the changing numbers and types of transmitters installed. In this work, the method of retrospective estimation of exposure dose is described, and the results of the assessment carried out at three kinds of typical RTCN are discussed. The results of the analysis indicate that the workers of RTCN are exposed primarily to electromagnetic fields of VHF and UHF bands, but this exposure may be considered as admissible, hence it should not exert an adverse effect on the workers' health.

  14. Indoor transformer stations and ELF magnetic field exposure: use of transformer structural characteristics to improve exposure assessment.

    PubMed

    Okokon, Enembe Oku; Roivainen, Päivi; Kheifets, Leeka; Mezei, Gabor; Juutilainen, Jukka

    2014-01-01

    Previous studies have shown that populations of multiapartment buildings with indoor transformer stations may serve as a basis for improved epidemiological studies on the relationship between childhood leukaemia and extremely-low-frequency (ELF) magnetic fields (MFs). This study investigated whether classification based on structural characteristics of the transformer stations would improve ELF MF exposure assessment. The data included MF measurements in apartments directly above transformer stations ("exposed" apartments) in 30 buildings in Finland, and reference apartments in the same buildings. Transformer structural characteristics (type and location of low-voltage conductors) were used to classify exposed apartments into high-exposure (HE) and intermediate-exposure (IE) categories. An exposure gradient was observed: both the time-average MF and time above a threshold (0.4 μT) were highest in the HE apartments and lowest in the reference apartments, showing a statistically significant trend. The differences between HE and IE apartments, however, were not statistically significant. A simulation exercise showed that the three-category classification did not perform better than a two-category classification (exposed and reference apartments) in detecting the existence of an increased risk. However, data on the structural characteristics of transformers is potentially useful for evaluating exposure-response relationship.

  15. Privacy Act System of Records: Libby Asbestos Exposure Assessment Records, EPA-48

    EPA Pesticide Factsheets

    Learn about the Libby Asbestos Exposure Assessment Records System, including who is covered in the system, the purpose of data collection, routine uses for the system's records, and other security procedure.

  16. Modeling Joint Exposures and Health Outcomes for Cumulative Risk Assessment: the Case of Radon and Smoking

    EPA Science Inventory

    Community-based cumulative risk assessment requires characterization of exposures to multiple chemical and non-chemical stressors, with consideration of how the non-chemical stressors may influence risks from chemical stressors. Residential radon provides an interesting case exam...

  17. The Future of Exposure Assessment: Perspectives from the X2012 Conference

    EPA Science Inventory

    The British Occupational Hygiene Society, in collaboration with the Institute of Occupational Medicine, the University of Manchester, the UK Health and Safety Executive, and the University of Aberdeen hosted the 7th International Conference on the Science of Exposure Assessment (...

  18. 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...

  19. Assessment of Serum Biomarkers in Rats After Exposure to Pesticides of Different Chemical Classes

    EPA Science Inventory

    There is increasing emphasis on the use of biomarkers of adverse outcomes in safety assessment and translational research. We evaluated serum biomarkers and targeted metabolite profiles after exposure to pesticides (permethrin, deltamethrin, imidacloprid, carbaryl, triadimefon...

  20. Webinar Presentation: Epidemiologic Studies of the Effects of Toxic Exposures on Brain and Behavior: Neuropsychological Assessment

    EPA Pesticide Factsheets

    This presentation, Epidemiologic Studies of the Effects of Toxic Exposures on Brain and Behavior: Neuropsychological Assessment, was given at the NIEHS/EPA Children's Centers 2015 Webinar Series: Interdisciplinary Approaches to Neurodevelopment.

  1. Effect of training, education, professional experience, and need for cognition on accuracy of exposure assessment decision-making.

    PubMed

    Vadali, Monika; Ramachandran, Gurumurthy; Banerjee, Sudipto

    2012-04-01

    accuracy of judgments and the various characteristics describing the participants. Data interpretation training (P < 0.0001), the company that the hygienist worked for (P < 0.0001), the total number of years hygienists had experience doing exposure assessments (P < 0.0001), and professional certifications (P < 0.0001) held by hygienists were found to be significant determinants of accurately predicting the correct exposure category for DITs as well as for task-specific judgment accuracy. Years of experience with a particular task (P < 0.0001), task evaluated, and the number of datapoints used for making judgments were found to be significant predictors of task-specific judgment accuracy. The NFC score was a predictor of the improvement in task judgment accuracy after training. The NFC score was itself predicted by determinants, such as company, years on current job, years of exposure assessment experience, and professional certifications. The results of this study are relevant not only for the case of industrial hygienists making exposure judgments prospectively but also possibly for those hygienists engaged in retrospective exposure assessments for epidemiological studies.

  2. Assessment of noise exposure in a hospital kitchen.

    PubMed

    Achutan, Chandran

    2009-01-01

    In March 2007, the National Institute for Occupational Safety and Health (NIOSH) was asked to evaluate the noise exposure of employees in the Nutrition and Food Services Department of a large hospital, because of noise concerns raised after the installation of the PowerSoak dishwashing system. Eleven employees (two cooks, eight food service workers, and a materials handler) contributed 13 full-shift and two task-based personal noise dosimetry measures over two days. The noise levels for two food service workers assigned to the pots and pans room (85.1 and 85.2dBA), a cook working in the food preparation area (85.9 dBA), and a food service worker assigned to the dishwashing room (89.5 dBA) exceeded the NIOSH Recommended Exposure Limit (REL); however, none of the measures exceeded the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL). The noise level from the PowerSoak dishwashing system alone was not excessive, but additional noise from the food preparation area (primarily from blenders and utensils), and from metal-to-metal contact between stainless steel pots and pans and metal racks, may explain exposures above the NIOSH REL for employees in the pots and pans room. The cooks were exposed to many intermittent impact noise sources, such as, metal-to-metal contact between utensils and the use of industrial-size blenders. We recommended that metal-to-metal contact be reduced as much as possible throughout the Nutrition and Food Services Department, and hearing protectors be provided to employees in the dishwashing room until engineering controls were in place.

  3. Molecular epizootiology: Assessment of exposure to genotoxic compounds in teleosts

    SciTech Connect

    Stein, J.E.; Reichert, W.L.; Varanasi, U.

    1994-12-01

    The recent development of techniques to measure levels of carcinogens covalently bound to DNA provides the opportunity to use DNA adducts as molecular dosimeters of exposure to environmental carcinogens and mutagens. This is especially important because epizootiologic studies have shown a positive association between environmental carcinogens, such as polycyclic aromatic hydrocarbons, and increased prevalence of neoplasms and related lesions, primarily in liver, of benthic fish species from a wide range of urban and industrialized areas. In studies with wild fish and mammalian species the {sup 32}P-postlabeling assay, as developed for aromatic compounds, has been used most extensively because of its high sensitivity and ability to detect structurally uncharacterized adducts. The results to date of field and laboratory studies show that hepatic DNA adducts detected in fish are associated with increased exposure to environmental polycyclic aromatic compounds in the preponderance of species examined, whereas in the limited studies with wild mammals, such a relationship is equivocal at present. The findings with fish suggest that DNA adducts, as measured by {sup 32}P-postlabeling, have the potential to be effective molecular dosimeters of exposure to environmental carcinogenic aromatic compounds and thereby may lead to an improved understanding of the etiology of neoplasia in wild teleosts. 38 refs., 3 figs.

  4. Continuous 3-day exposure assessment of workplace manufacturing silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Lee, Ji Hyun; Ahn, Kangho; Kim, Sun Man; Jeon, Ki Soo; Lee, Jong Seong; Yu, Il Je

    2012-09-01

    With the increased production and widespread use of nanomaterials, human and environmental exposure to nanomaterials is inevitably increasing. Therefore, this study monitored the possible nanoparticle exposure at a workplace that manufactures silver nanoparticles. To estimate the potential exposure of workers, personal sampling, area monitoring, and real-time monitoring were conducted over 3 days using a scanning mobility particle sizer and dust monitor at a workplace where the workers handle nanomaterials. The area sampling concentrations obtained from the injection room showed the highest concentration, ranging from 0.00501 to 0.28873 mg/m3. However, apart from the injection room, none of the area samplings obtained from other locations showed a concentration higher than 0.0013 mg/m3. Meanwhile, the personal sampling concentrations ranged from 0.00004 to 0.00243 mg/m3 over the 3 days of sampling, which was much lower than the silver TLV. The particle number concentrations at the silver nanoparticle manufacturing workplace were 911,170 (1st day), 1,631,230 (2nd day), and 1,265,024 (3rd day) particles/cm3 with a size range of 15-710.5 nm during the operation of the reactor, while the concentration decreased to 877,364.9 (1st day), 492,732 (2nd day), and 344,343 (3rd day) particles/cm3 when the reactor was stopped.

  5. Multimedia lead exposure and associated risk assessment in Dhaka, Bangladesh

    SciTech Connect

    Sarwar, M.

    1998-12-31

    Motor vehicles consume the largest amount of leaded gasoline in Bangladesh. The number of vehicles and fuel consumption have increased significantly in recent years. These vehicles, which are believed to be the major sources of lead emissions in Dhaka, may cause an excessive level of lead exposure in children. The paper describes the results of a study conducted to determine risk associated with the multimedia lead exposure for children in Dhaka. Specifically, data related to lead content in air and soil in Dhaka were collected and used to estimate the blood lead levels in children. The Integrated Exposure Uptake Biokinetics Model, developed by the United States Environmental Protection Agency (USEPA), was used. Bangladesh is yet to adopt any blood lead standards. The results of the study indicated that the model predicted geometric blood lead levels in children in Dhaka are significantly below the blood lead standard recommended by the World Health Organization (WHO). It was also found that children in Dhaka are not expected to contain blood lead levels higher than the WHO recommended standard.

  6. Assessing human exposure to power-frequency electric and magnetic fields.

    PubMed Central

    Kaune, W T

    1993-01-01

    This paper reviews published literature and current problems relating to the assessment of occupational and residential human exposures to power-frequency electric and magnetic fields. Available occupational exposure data suggest that the class of job titles known as electrical workers may be an effective surrogate for time-weighted-average (TWA) magnetic-field (but not electric-field) exposure. Current research in occupational-exposure assessment is directed to the construction of job-exposure matrices based on electric- and magnetic-field measurements and estimates of worker exposures to chemicals and other factors of interest. Recent work has identified five principal sources of residential magnetic fields: electric power transmission lines, electric power distribution lines, ground currents, home wiring, and home appliances. Existing residential-exposure assessments have used one or more of the following techniques: questionnaires, wiring configuration coding, theoretical field calculations, spot electric- and magnetic-field measurements, fixed-site magnetic-field recordings, personal- exposure measurements, and geomagnetic-field measurements. Available normal-power magnetic-field data for residences differ substantially between studies. It is not known if these differences are due to geographical differences, differences in measurement protocols, or instrumentation differences. Wiring codes and measured magnetic fields (but not electric fields) are associated weakly. Available data suggest, but are far from proving, that spot measurements may be more effective than wire codes as predictors of long-term historical magnetic-field exposure. Two studies find that away-from-home TWA magnetic-field exposures are less variable than at-home exposures. The importance of home appliances as contributors to total residential magnetic-field exposure is not known at this time. It also is not known what characteristics (if any) of residential electric and magnetic fields are

  7. Approaches to Children’s Exposure Assessment: Case Study with Diethylhexylphthalate (DEHP)

    PubMed Central

    Ginsberg, Gary; Ginsberg, Justine; Foos, Brenda

    2016-01-01

    Children’s exposure assessment is a key input into epidemiology studies, risk assessment and source apportionment. The goals of this article are to describe a methodology for children’s exposure assessment that can be used for these purposes and to apply the methodology to source apportionment for the case study chemical, diethylhexylphthalate (DEHP). A key feature is the comparison of total (aggregate) exposure calculated via a pathways approach to that derived from a biomonitoring approach. The 4-step methodology and its results for DEHP are: (1) Prioritization of life stages and exposure pathways, with pregnancy, breast-fed infants, and toddlers the focus of the case study and pathways selected that are relevant to these groups; (2) Estimation of pathway-specific exposures by life stage wherein diet was found to be the largest contributor for pregnant women, breast milk and mouthing behavior for the nursing infant and diet, house dust, and mouthing for toddlers; (3) Comparison of aggregate exposure by pathways vs biomonitoring-based approaches wherein good concordance was found for toddlers and pregnant women providing confidence in the exposure assessment; (4) Source apportionment in which DEHP presence in foods, children’s products, consumer products and the built environment are discussed with respect to early life mouthing, house dust and dietary exposure. A potential fifth step of the method involves the calculation of exposure doses for risk assessment which is described but outside the scope for the current case study. In summary, the methodology has been used to synthesize the available information to identify key sources of early life exposure to DEHP. PMID:27376320

  8. Hexavalent chromium compounds in the workplace: assessing the extent and magnitude of occupational exposure in Italy.

    PubMed

    Scarselli, Alberto; Binazzi, Alessandra; Marzio, Davide Di; Marinaccio, Alessandro; Iavicoli, Sergio

    2012-01-01

    Hexavalent chromium (Cr(VI)) compounds have been classified as carcinogenic to humans. This study evaluates the extent and magnitude of occupational exposures to Cr(VI) in Italy. Data were collected from exposure registries of companies compulsorily notified by the National Workers' Compensation Authority. Each measurement was characterized by economic activity sector, work force size, worker personal data, job description, year of measurement, and level of exposure. Descriptive statistical analysis was carried out on the retrieved information. The number of workers potentially exposed was estimated for some industrial sectors. A mixed-effects model was adopted to evaluate the association between exposure variables and exposure concentrations. Over 8400 measurements of Cr(VI) exposures were selected from the database of registries for 1996-2009. Most exposures occurred in the manufacture of fabricated metal products (>50%), and the occupational group most frequently measured was metal finishing-, plating- and coating-machine operators (>52%). Measurements were associated with various Cr(VI) compounds, including chromium trioxide, potassium dichromate, sodium dichromate, strontium chromate, and zinc chromate. Cr(VI) exposure has decreased in more recent years, and the fixed-effects (Cr(VI) compound, activity sector, size and location of the facility, job category, and year of measurement of the final statistical model explained more than 70% of the variance in the observed exposure data. This study summarized data recorded in the Italian occupational exposure database and identified specific exposure patterns to Cr(VI). The mean level of exposure to Cr(VI) was 30.41 μg/m³, and 50,118 workers were estimated at exposure risk in the selected industrial sectors. Systematic recording of occupational exposures is a source of data that allows recognition of high risk situations and improvements in exposure assessment for epidemiologic studies.

  9. Assessment of carbon nanoparticle exposure on murine macrophage function

    NASA Astrophysics Data System (ADS)

    Suro-Maldonado, Raquel M.

    There is growing concern about the potential cytotoxicity of nanoparticles. Exposure to respirable ultrafine particles (2.5uM) can adversely affect human health and have been implicated with episodes of increased respiratory diseases such as asthma and allergies. Nanoparticles are of particular interest because of their ability to penetrate into the lung and potentially elicit health effects triggering immune responses. Nanoparticles are structures and devises with length scales in the 1 to 100-nanometer range. Black carbon (BC) nanoparticles have been observed to be products of combustion, especially flame combustion and multi-walled carbon nanotubes (MWCNT) have been shown to be found in both indoor and outdoor air. Furthermore, asbestos, which have been known to cause mesothelioma as well as lung cancer, have been shown to be structurally identical to MWCNTs. The aims of these studies were to examine the effects of carbon nanoparticles on murine macrophage function and clearance mechanisms. Macrophages are immune cells that function as the first line of defense against invading pathogens and are likely to be amongst the first cells affected by nanoparticles. Our research focused on two manufactured nanoparticles, MWCNT and BC. The two were tested against murine-derived macrophages in a chronic contact model. We hypothesized that long-term chronic exposure to carbon nanoparticles would decrease macrophages ability to effectively respond to immunological challenge. Production of nitric oxide (NO), tumor necrosis factor alpha (TNF-alpha), cell surface macrophage; activation markers, reactive oxygen species formation (ROS), and antigen processing and presentation were examined in response to lipopolysaccharide (LPS) following a 144hr exposure to the particulates. Data demonstrated an increase in TNF-alpha, and NO production; a decrease in phagocytosis and antigen processing and presentation; and a decrease in the expression levels of cell surface macrophage

  10. Assessment of noise exposure for basketball sports referees.

    PubMed

    Masullo, Massimiliano; Lenzuni, Paolo; Maffei, Luigi; Nataletti, Pietro; Ciaburro, Giuseppe; Annesi, Diego; Moschetto, Antonio

    2016-01-01

    Dosimetric measurements carried out on basketball referees have shown that whistles not only generate very high peak sound pressure levels, but also play a relevant role in determining the overall exposure to noise of the exposed subjects. Because of the peculiar geometry determined by the mutual positions of the whistle, the microphone, and the ear, experimental data cannot be directly compared with existing occupational noise exposure and/or action limits. In this article, an original methodology, which allows experimental results to be reliably compared with the aforementioned limits, is presented. The methodology is based on the use of two correction factors to compensate the effects of the position of the dosimeter microphone (fR) and of the sound source (fS). Correction factors were calculated by means of laboratory measurements for two models of whistles (Fox 40 Classic and Fox 40 Sonik) and for two head orientations (frontal and oblique).Results sho w that for peak sound pressure levels the values of fR and fS, are in the range -8.3 to -4.6 dB and -6.0 to -1.7 dB, respectively. If one considers the Sound Exposure Levels (SEL) of whistle events, the same correction factors are in the range of -8.9 to -5.3 dB and -5.4 to -1.5 dB, respectively. The application of these correction factors shows that the corrected weekly noise exposure level for referees is 80.6 dB(A), which is slightly in excess of the lower action limit of the 2003/10/EC directive, and a few dB below the Recommended Exposure Limit (REL) proposed by the National Institute for Occupational Safety and Health (NIOSH). The corrected largest peak sound pressure level is 134.7 dB(C) which is comparable to the lower action limit of the 2003/10/EC directive, but again substantially lower than the ceiling limit of 140 dB(A) set by NIOSH.

  11. Methods for assessing the extent of exposure and effects of air pollution.

    PubMed Central

    Krzyzanowski, M

    1997-01-01

    BACKGROUND AND OBJECTIVES: In many places in Europe, the ambient air pollution exceeds the levels considered to be safe for health. The objective of the paper is to review and summarise the methods of assessment of its impact on health, and to indicate the contributions of various research disciplines, particularly environmental epidemiology. METHODS: The framework for assessment of impact is based on a four stage model: assessment of release of pollutant; assessment of exposure; assessment of the consequence; and risk estimation. RESULTS: Epidemiology is crucial in providing the data for the assessment of consequence. The criteria that determine the use of epidemiological studies for this task include lack of bias, correct control of confounding, and measured estimates of exposure. At present, those criteria are easier to satisfy for studies of short term effects on health than for the delayed consequences of exposure, or exposure accumulated over a prolonged period. Combinations of results from various populations through meta-analysis of existing studies or conducting multicentre studies is often necessary to increase the reliability of the consequence assessment stage. CONCLUSION: To assess the impact on health systematically helps to focus on actions to limit air pollutants with the greatest impacts on human health and on the most affected populations. This method allows identification of the most pertinent questions which have to be answered by studies on relations between pollution and health and on exposure of populations to air pollutants. Epidemiology has considerable potential to contribute to this research. PMID:9155775

  12. Integrating Exposure into Chemical Alternatives Assessment Using a Qualitative Approach

    EPA Science Inventory

    Most alternatives assessments (AA) published to date are largely hazard-based rankings, and as such may not represent a fully informed consideration of the advantages and disadvantages of possible alternatives. With an assessment goal of identifying an alternative chemical that i...

  13. Electromagnetic field exposure assessment in Europe radiofrequency fields (10 MHz-6 GHz).

    PubMed

    Gajšek, Peter; Ravazzani, Paolo; Wiart, Joe; Grellier, James; Samaras, Theodoros; Thuróczy, György

    2015-01-01

    Average levels of exposure to radiofrequency (RF) electromagnetic fields (EMFs) of the general public in Europe are difficult to summarize, as exposure levels have been reported differently in those studies in which they have been measured, and a large proportion of reported measurements were very low, sometimes falling below detection limits of the equipment used. The goal of this paper is to present an overview of the scientific literature on RF EMF exposure in Europe and to characterize exposure within the European population. A comparative analysis of the results of spot or long-term RF EMF measurements in the EU indicated that mean electric field strengths were between 0.08 V/m and 1.8 V/m. The overwhelming majority of measured mean electric field strengths were <1 V/m. It is estimated that <1% were above 6 V/m and <0.1% were above 20 V/m. No exposure levels exceeding European Council recommendations were identified in these surveys. Most population exposures from signals of radio and television broadcast towers were observed to be weak because these transmitters are usually far away from exposed individuals and are spatially sparsely distributed. On the other hand, the contribution made to RF exposure from wireless telecommunications technology is continuously increasing and its contribution was above 60% of the total exposure. According to the European exposure assessment studies identified, three population exposure categories (intermittent variable partial body exposure, intermittent variable low-level whole-body (WB) exposure and continuous low-level WB exposure) were recognized by the authors as informative for possible future risk assessment.

  14. Aggregate Exposure and Cumulative Risk Assessment--Integrating Occupational and Non-occupational Risk Factors.

    PubMed

    Lentz, T J; Dotson, G S; Williams, P R D; Maier, A; Gadagbui, B; Pandalai, S P; Lamba, A; Hearl, F; Mumtaz, M

    2015-01-01

    Occupational exposure limits have traditionally focused on preventing morbidity and mortality arising from inhalation exposures to individual chemical stressors in the workplace. While central to occupational risk assessment, occupational exposure limits have limited application as a refined disease prevention tool because they do not account for all of the complexities of the work and non-occupational environments and are based on varying health endpoints. To be of greater utility, occupational exposure limits and other risk management tools could integrate broader consideration of risks from multiple exposure pathways and routes (aggregate risk) as well as the combined risk from exposure to both chemical and non-chemical stressors, within and beyond the workplace, including the possibility that such exposures may cause interactions or modify the toxic effects observed (cumulative risk). Although still at a rudimentary stage in many cases, a variety of methods and tools have been developed or are being used in allied risk assessment fields to incorporate such considerations in the risk assessment process. These approaches, which are collectively referred to as cumulative risk assessment, have potential to be adapted or modified for occupational scenarios and provide a tangible path forward for occupational risk assessment. Accounting for complex exposures in the workplace and the broader risks faced by the individual also requires a more complete consideration of the composite effects of occupational and non-occupational risk factors to fully assess and manage worker health problems. Barriers to integrating these different factors remain, but new and ongoing community-based and worker health-related initiatives may provide mechanisms for identifying and integrating risk from aggregate exposures and cumulative risks from all relevant sources, be they occupational or non-occupational.

  15. The Human Exposure Model (HEM): A Tool to Support Rapid Assessment of Human Health Impacts from Near-Field Consumer Product Exposures

    EPA Science Inventory

    The US EPA is developing an open and publically available software program called the Human Exposure Model (HEM) to provide near-field exposure information for Life Cycle Impact Assessments (LCIAs). Historically, LCIAs have often omitted impacts from near-field sources of exposur...

  16. Air pollution in moderately polluted urban areas: How does the definition of "neighborhood" impact exposure assessment?

    PubMed

    Tenailleau, Quentin M; Mauny, Frédéric; Joly, Daniel; François, Stéphane; Bernard, Nadine

    2015-11-01

    Environmental health studies commonly quantify subjects' pollution exposure in their neighborhood. How this neighborhood is defined can vary, however, leading to different approaches to quantification whose impacts on exposure levels remain unclear. We explore the relationship between neighborhood definition and exposure assessment. NO2, benzene, PM10 and PM2.5 exposure estimates were computed in the vicinity of 10,825 buildings using twelve exposure assessment techniques reflecting different definitions of "neighborhood". At the city scale, its definition does not significantly influence exposure estimates. It does impact levels at the building scale, however: at least a quarter of the buildings' exposure estimates for a 400 m buffer differ from the estimated 50 m buffer value (±1.0 μg/m(3) for NO2, PM10 and PM2.5; and ±0.05 μg/m(3) for benzene). This variation is significantly related to the definition of neighborhood. It is vitally important for investigators to understand the impact of chosen assessment techniques on exposure estimates.

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

    PubMed Central

    Lesmes-Fabian, Camilo; Binder, Claudia R.

    2013-01-01

    Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area. PMID:23528812

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

    PubMed

    Lesmes-Fabian, Camilo; Binder, Claudia R

    2013-03-25

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

  19. Release of nanomaterials from solid nanocomposites and consumer exposure assessment - a forward-looking review.

    PubMed

    Mackevica, Aiga; Foss Hansen, Steffen

    2016-08-01

    The European chemical legislation requires manufacturers and importers of chemicals to do consumer exposure assessment when the chemical has certain hazards associated to it (e.g. explosive, carcinogenicity, and hazardous to the aquatic environment), but the question is how this obligation can be met in light of the scientific uncertainty and technical challenges related to exposure assessment of nanomaterials. In this paper, we investigate to what extent the information and data in the literature can be used to perform consumer exposure assessment according to the REACH requirements and we identify and discuss the key data needs and provide recommendations for consumer exposure assessment of nanomaterials. In total, we identified 76 studies of relevance. Most studies have analyzed the release of Ag and TiO2 from textiles and paints, and CNT and SiO2 from nanocomposites. Less than half of the studies report their findings in a format that can be used for exposure assessment under REACH, and most do not include characterization of the released particles. Although inhalation, dermal, and oral exposures can be derived using the guidelines on how to complete consumer exposure assessments under REACH, it is clear that the equations are not developed to take the unique properties of nanomaterials into consideration. Future research is therefore needed on developing more generalized methods for representing nanomaterial release from different product groups at relevant environmental conditions. This includes improving the analytical methods for determining nanomaterial alteration and transformation, as well as quantification, which could subsequently lead to more nano-specific consumer exposure assessment models.

  20. Exposure assessment of residents living near a wood treatment plant.

    PubMed

    Dahlgren, James; Warshaw, Raphael; Horsak, Randy D; Parker, Frank M; Takhar, Harpreet

    2003-06-01

    We report the results of environmental sampling and modeling in a neighborhood adjacent to a wood processing plant. This plant used creosote and pentachlorophenol (PCP) to treat wood for over 70 years. Between 1999 and 2001, environmental samples were obtained to quantify the level of environmental contamination from the wood processing plant. Blood from 10 residents was measured for chlorinated dioxins and dibenzofurans. Soil sediment samples from drainage ditches and attic/dust samples from nearby residents' homes were tested for polychlorinated dioxins, furans, and polycyclic aromatic hydrocarbons (PAH). The dioxin congeners analysis of the 10 residents revealed elevated valued for octachlorodibenzo-p-dioxin and heptachlorodibenzo-p-dioxin compatible with PCP as the source. The levels of carcinogenic PAHs were higher than background levels and were similar to soil contamination on wood preserving sites. Wipe sampling in the kitchens of 11 homes revealed that 20 of the 33 samples were positive for octachlorinated dioxins with a mean value of 10.27 ng/m2. The soil, ditch samples, and positive wipe samples from the homes indicate a possible ongoing route of exposure to the contaminants in the homes of these residents. Modeled air exposure estimated for the wood processing waste chemicals indicate some air exposure to combustion products. The estimated air levels for benzo(a)pyrene and tetrachlorodibenzodiozin in this neighborhood exceeded the recommended levels for these compounds in some states. The quantitative data presented suggest a significant contamination of a neighborhood by wood processing waste chemicals. These findings suggest the need for more stringent regulations on waste discharges from wood treatment plants.

  1. Korean Ministry of Environment's web-based visual consumer product exposure and risk assessment system (COPER).

    PubMed

    Lee, Hunjoo; Lee, Kiyoung; Park, Ji Young; Min, Sung-Gi

    2017-04-08

    With support from the Korean Ministry of the Environment (ME), our interdisciplinary research staff developed the COnsumer Product Exposure and Risk assessment system (COPER). This system includes various databases and features that enable the calculation of exposure and determination of risk caused by consumer products use. COPER is divided into three tiers: the integrated database layer (IDL), the domain specific service layer (DSSL), and the exposure and risk assessment layer (ERAL). IDL is organized by the form of the raw data (mostly non-aggregated data) and includes four sub-databases: a toxicity profile, an inventory of Korean consumer products, the weight fractions of chemical substances in the consumer products determined by chemical analysis and national representative exposure factors. DSSL provides web-based information services corresponding to each database within IDL. Finally, ERAL enables risk assessors to perform various exposure and risk assessments, including exposure scenario design via either inhalation or dermal contact by using or organizing each database in an intuitive manner. This paper outlines the overall architecture of the system and highlights some of the unique features of COPER based on visual and dynamic rendering engine for exposure assessment model on web.

  2. The Utility of Maze Accurate Response Rate in Assessing Reading Comprehension in Upper Elementary and Middle School Students

    ERIC Educational Resources Information Center

    McCane-Bowling, Sara J.; Strait, Andrea D.; Guess, Pamela E.; Wiedo, Jennifer R.; Muncie, Eric

    2014-01-01

    This study examined the predictive utility of five formative reading measures: words correct per minute, number of comprehension questions correct, reading comprehension rate, number of maze correct responses, and maze accurate response rate (MARR). Broad Reading cluster scores obtained via the Woodcock-Johnson III (WJ III) Tests of Achievement…

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

    PubMed Central

    Duarte, Sofia C.; Pena, Angelina; Lino, Celeste M.

    2010-01-01

    In Portugal, the climate, dietary habits, and food contamination levels present the characteristics for higher population susceptibility to ochratoxin A (OTA), one of the known mycotoxins with the greatest public health and agro-economic importance. In this review, following a brief historical insight on OTA research, a summary of the available data on OTA occurrence in food (cereals, bread, wine, meat) and biological fluids (blood, urine) is made. With this data, an estimation of intake is made to ascertain and update the risk exposure estimation of the Portuguese population, in comparison to previous studies and other populations. PMID:22069635

  4. Assessing exposure to air toxics relative to asthma.

    PubMed

    Weisel, Clifford P

    2002-08-01

    Asthma is a respiratory disease whose prevalence has been increasing since the mid 1970s and that affects more than 14.6 million residents of the United States. Environmental triggers of asthma include air pollutants that are respiratory irritants. Air toxics emitted into the ambient air are listed in the 1990 Clean Air Act Amendments as hazardous air pollutants (HAPs) if they can adversely affect human health, including the respiratory tract. HAPs include particulate and gaseous-phase pollutants, individual organic compounds and metals, and mixtures. Associations between asthma exacerbation and both particles and indoor volatile organic compounds (VOCs), often referred to as indoor air quality, have been reported. Studies conducted in the United States, Canada, and Europe over the past two decades have shown that most people living in the developed countries spend the majority of their time indoors and that the air concentrations of many air toxics or HAPs are higher indoors than in the ambient air in urban, suburban, and rural settings. Elevated indoor air concentrations result from emissions of air toxics from consumer products, household furnishings, and personal activities. The Relationship of Indoor, Outdoor and Personal Air (RIOPA) study was designed to oversample homes in close proximity to ambient sources, excluding residences where smokers lived, to determine the contribution of ambient emissions to air toxics exposure. The ratios of indoor to outdoor air concentrations of some VOCs in homes measured during RIOPA were much greater than one, and for most other VOCs that had indoor-to-outdoor ratios close to unity in the majority of homes, elevated ratios were found in the paired samples with the highest concentration. Thus, although ambient emissions contribute to exposure of some air toxics indoors as well as outdoors, this was not true for all of the air toxics and especially for the higher end of exposures to most volatile organic air toxics examined

  5. Exposure assessment of adult intake of bisphenol A (BPA) with emphasis on canned food dietary exposures.

    PubMed

    Lorber, Matthew; Schecter, Arnold; Paepke, Olaf; Shropshire, William; Christensen, Krista; Birnbaum, Linda

    2015-04-01

    Bisphenol A (BPA) is a high-volume, synthetic compound found in epoxy resins and plastics used in food packaging. Food is believed to be a major source of BPA intake. In this study, we measured the concentration of BPA in convenience samplings of foodstuffs purchased in Dallas, Texas. Sampling entailed collection of 204 samples of fresh, frozen, and canned foods in two rounds in 2010. BPA was positive in 73% of the canned food samples, while it was found in only 7% of non-canned foods at low concentrations. The results of this food sampling program were used to calculate adult dietary intakes of BPA. A pathway approach combined food intakes, a "canned fraction" parameter which described what portion of total intake of that food came from canned products, and measured food concentrations. Dietary intakes were calculated as 12.6 ng/kg-day, of which 12.4 ng/kg-day was from canned foods. Canned vegetable intakes alone were 11.9 ng/kg-day. This dietary intake was compared to total intakes of BPA estimated from urine measurements of the National Health and Nutrition Examination Survey (NHANES). Total adult central tendency intakes ranged from 30 to 70 ng/kg-day for NHANES cycles between 2005 and 2010. Three possibilities were explored to explain the difference between these two approaches for intake estimation. Not all foods which may have been canned, particularly canned beverages such as soft drinks, were sampled in our food sampling program. Second, non-food pathways of exposure may be important for adults, including thermal paper exposures, and dust and air exposures. Finally, our canned food concentrations may not be adequately representative of canned foods in the United States; they were found to be generally lower compared to canned food concentrations measured in six other worldwide food surveys including three in North America. Our finding that canned food concentrations greatly exceeded non-canned concentrations was consistent with other studies, and

  6. Exposure assessment of adult intake of bisphenol A (BPA) with emphasis on canned food dietary exposures

    PubMed Central

    Lorber, Matthew; Schecter, Arnold; Paepke, Olaf; Shropshire, William; Christensen, Krista; Birnbaum, Linda

    2015-01-01

    Bisphenol A (BPA) is a high-volume, synthetic compound found in epoxy resins and plastics used in food packaging. Food is believed to be a major source of BPA intake. In this study, we measured the concentration of BPA in convenience samplings of foodstuffs purchased in Dallas, Texas. Sampling entailed collection of 204 samples of fresh, frozen, and canned foods in two rounds in 2010. BPA was positive in 73% of the canned food samples, while it was found in only 7% of non-canned foods at low concentrations. The results of this food sampling program were used to calculate adult dietary intakes of BPA. A pathway approach combined food intakes, a “canned fraction” parameter which described what portion of total intake of that food came from canned products, and measured food concentrations. Dietary intakes were calculated as 12.6 ng/kg-day, of which 12.4 ng/kg-day was from canned foods. Canned vegetable intakes alone were 11.9 ng/kg-day. This dietary intake was compared to total intakes of BPA estimated from urine measurements of the National Health and Nutrition Examination Survey (NHANES). Total adult central tendency intakes ranged from 30 to 70 ng/kg-day for NHANES cycles between 2005 and 2010. Three possibilities were explored to explain the difference between these two approaches for intake estimation. Not all foods which may have been canned, particularly canned beverages such as soft drinks, were sampled in our food sampling program. Second, non-food pathways of exposure may be important for adults, including thermal paper exposures, and dust and air exposures. Finally, our canned food concentrations may not be adequately representative of canned foods in the United States; they were found to be generally lower compared to canned food concentrations measured in six other worldwide food surveys including three in North America. Our finding that canned food concentrations greatly exceeded non-canned concentrations was consistent with other studies, and

  7. Assessment of general public exposure to LTE and RF sources present in an urban environment.

    PubMed

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

    2010-10-01

    For the first time, in situ electromagnetic field exposure of the general public to fields from long term evolution (LTE) cellular base stations is assessed. Exposure contributions due to different radiofrequency (RF) sources are compared with LTE exposure at 30 locations in Stockholm, Sweden. Total exposures (0.2-2.6 V/m) satisfy the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels (from 28 V/m for frequency modulation (FM), up to 61 V/m for LTE) at all locations. LTE exposure levels up to 0.8 V/m were measured, and the average contribution of the LTE signal to the total RF exposure equals 4%.

  8. Assessment of mercury exposure among small-scale gold miners using mercury stable isotopes

    SciTech Connect

    Sherman, Laura S.; Blum, Joel D.; Basu, Niladri; Rajaee, Mozhgon; Evers, David C.; Buck, David G.; Petrlik, Jindrich; DiGangi, Joseph

    2015-02-15

    Total mercury (Hg) concentrations in hair and urine are often used as biomarkers of exposure to fish-derived methylmercury (MeHg) and gaseous elemental Hg, respectively. We used Hg stable isotopes to assess the validity of these biomarkers among small-scale gold mining populations in Ghana and Indonesia. Urine from Ghanaian miners displayed similar Δ{sup 199}Hg values to Hg derived from ore deposits (mean urine Δ{sup 199}Hg=0.01‰, n=6). This suggests that urine total Hg concentrations accurately reflect exposure to inorganic Hg among this population. Hair samples from Ghanaian miners displayed low positive Δ{sup 199}Hg values (0.23–0.55‰, n=6) and low percentages of total Hg as MeHg (7.6–29%, n=7). These data suggest that the majority of the Hg in these miners' hair samples is exogenously adsorbed inorganic Hg and not fish-derived MeHg. Hair samples from Indonesian gold miners who eat fish daily displayed a wider range of positive Δ{sup 199}Hg values (0.21–1.32‰, n=5) and percentages of total Hg as MeHg (32–72%, n=4). This suggests that total Hg in the hair samples from Indonesian gold miners is likely a mixture of ingested fish MeHg and exogenously adsorbed inorganic Hg. Based on data from both populations, we suggest that total Hg concentrations in hair samples from small-scale gold miners likely overestimate exposure to MeHg from fish consumption. - Highlights: • Mercury isotopes were measured in hair and urine from small-scale gold miners. • Mercury isotopes indicate that Hg in urine comes from mining activity. • Mercury isotopes suggest Hg in hair is a mixture of fish MeHg and inorganic Hg. • A large percentage of Hg in miner’s hair is released during amalgam burning and adsorbed.

  9. A Review of the Field on Children's Exposure to Environmental Contaminants: A Risk Assessment Approach.

    PubMed

    Ferguson, Alesia; Penney, Rosalind; Solo-Gabriele, Helena

    2017-03-04

    Background: Children must be recognized as a sensitive population based on having biological systems and organs in various stages of development. The processes of absorption, distribution, metabolism and elimination of environmental contaminants within a child's body are considered less advanced than those of adults, making them more susceptible to disease outcomes following even small doses. Children's unique activities of crawling and practicing increased hand-to-mouth ingestion also make them vulnerable to greater exposures by certain contaminants within specific environments. Approach: There is a need to review the field of children's environmental exposures in order to understand trends and identify gaps in research, which may lead to better protection of this vulnerable and sensitive population. Therefore, explored here are previously published contemporary works in the broad area of children's environmental exposures and potential impact on health from around the world. A discussion of children's exposure to environmental contaminants is best organized under the last four steps of a risk assessment approach: hazard identification, dose-response assessment, exposure assessment (including children's activity patterns) and risk characterization. We first consider the many exposure hazards that exist in the indoor and outdoor environments, and emerging contaminants of concern that may help guide the risk assessment process in identifying focus areas for children. A section on special diseases of concern is also included. Conclusions: The field of children's exposures to environmental contaminants is broad. Although there are some well-studied areas offering much insight into children exposures, research is still needed to further our understanding of exposures to newer compounds, growing disease trends and the role of gene-environment interactions that modify adverse health outcomes. It is clear that behaviors of adults and children play a role in reducing or

  10. Exposure assessment for trihalomethanes in municipal drinking water and risk reduction strategy.

    PubMed

    Chowdhury, Shakhawat

    2013-10-01

    Lifetime exposure to disinfection byproducts (DBPs) in municipal water may pose risks to human health. Current approaches of exposure assessments use DBPs in cold water during showering, while warming of chlorinated water during showering may increase trihalomethane (THM) formation in the presence of free residual chlorine. Further, DBP exposure through dermal contact during showering is estimated using steady-state condition between the DBPs in shower water impacting on human skin and skin exposed to shower water. The lag times to achieve steady-state condition between DBPs in shower water and human skin can vary in the range of 9.8-391.2 min, while shower duration is often less than the lag times. Assessment of exposure without incorporating these factors might have misinterpreted DBP exposure in some previous studies. In this study, exposure to THMs through ingestion was estimated using cold water THMs, while THM exposure through inhalation and dermal contact during showering was estimated using THMs in warm water. Inhalation of THMs was estimated using THM partition into the shower air, while dermal uptake was estimated by incorporating lag times (e.g., unsteady and steady-state phases of exposure) during showering. Probabilistic approach was followed to incorporate uncertainty in the assessment. Inhalation and dermal contact during showering contributed 25-60% of total exposure. Exposure to THMs during showering can be controlled by varying shower stall volume, shower duration and air exchange rate following power law equations. The findings might be useful in understanding exposure to THMs, which can be extended to other volatile compounds in municipal water.

  11. Environmental exposure assessment in European birth cohorts: results from the ENRIECO project

    PubMed Central

    2013-01-01

    Environmental exposures during pregnancy and early life may have adverse health effects. Single birth cohort studies often lack statistical power to tease out such effects reliably. To improve the use of existing data and to facilitate collaboration among these studies, an inventory of the environmental exposure and health data in these studies was made as part of the ENRIECO (Environmental Health Risks in European Birth Cohorts) project. The focus with regard to exposure was on outdoor air pollution, water contamination, allergens and biological organisms, metals, pesticides, smoking and second hand tobacco smoke (SHS), persistent organic pollutants (POPs), noise, radiation, and occupational exposures. The review lists methods and data on environmental exposures in 37 European birth cohort studies. Most data is currently available for smoking and SHS (N=37 cohorts), occupational exposures (N=33), outdoor air pollution, and allergens and microbial agents (N=27). Exposure modeling is increasingly used for long-term air pollution exposure assessment; biomonitoring is used for assessment of exposure to metals, POPs and other chemicals; and environmental monitoring for house dust mite exposure assessment. Collaborative analyses with data from several birth cohorts have already been performed successfully for outdoor air pollution, water contamination, allergens, biological contaminants, molds, POPs and SHS. Key success factors for collaborative analyses are common definitions of main exposure and health variables. Our review emphasizes that such common definitions need ideally be arrived at in the study design phase. However, careful comparison of methods used in existing studies also offers excellent opportunities for collaborative analyses. Investigators can use this review to evaluate the potential for future collaborative analyses with respect to data availability and methods used in the different cohorts and to identify potential partners for a specific research

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

    PubMed

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

    2005-12-01

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

  13. Tools to Assess Community-Based Cumulative Risk and Exposures

    EPA Science Inventory

    Multiple agents and stressors can interact in a given community to adversely affect human and ecological conditions. A cumulative risk assessment (CRA) analyzes, characterizes, and potentially quantifies the effects from multiple stressors, which include chemical agents (for exam...

  14. Safety assessment of chronic oral exposure to iron oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Chamorro, Susana; Gutiérrez, Lucía; Vaquero, María Pilar; Verdoy, Dolores; Salas, Gorka; Luengo, Yurena; Brenes, Agustín; José Teran, Francisco

    2015-05-01

    Iron oxide nanoparticles with engineered physical and biochemical properties are finding a rapidly increasing number of biomedical applications. However, a wide variety of safety concerns, especially those related to oral exposure, still need to be addressed for iron oxide nanoparticles in order to reach clinical practice. Here, we report on the effects of chronic oral exposure to low doses of γ-Fe2O3 nanoparticles in growing chickens. Animal observation, weight, and diet intake reveal no adverse signs, symptoms, or mortality. No nanoparticle accumulation was observed in liver, spleen, and duodenum, with feces as the main excretion route. Liver iron level and duodenal villi morphology reflect the bioavailability of the iron released from the partial transformation of γ-Fe2O3 nanoparticles in the acid gastric environment. Duodenal gene expression studies related to the absorption of iron from γ-Fe2O3 nanoparticles indicate the enhancement of a ferric over ferrous pathway supporting the role of mucins. Our findings reveal that oral administration of iron oxide nanoparticles is a safe route for drug delivery at low nanoparticle doses.

  15. A retrospective cohort study among iron-steel workers in Anshan, China: exposure assessment.

    PubMed

    Hoshuyama, Tsutomu; Pan, Guowei; Tanaka, Chieko; Feng, Yiping; Yu, Lianzheng; Liu, Tiefu; Liu, Liming; Hanaoka, Tomoyuki; Takahashi, Ken

    2006-09-01

    Although adequate assessment of exposure is needed in epidemiological studies among foundry workers, previous studies are often lacking in this aspect. We conducted a retrospective cohort study of a Chinese iron and steel company with a 14-yr follow up during 1980-1993. Exposure assessment was performed for a single job, i.e., the current job for the active worker and the longest job for the retired or deceased worker as of the end of the follow-up, which was allocated as the surrogate of lifetime job and was applied to a job-exposure matrix. Of the 147,062 cohort members, 52,394 males (43%) and 5,291 females (21%) were exposed to any of 15 hazardous factors such as dust, silica, PAHs (polycyclic aromatic hydrocarbons), CO (carbon monoxide) and heat. In 2,104 randomly selected samples, the exposure assessment of exposed workers based on a single job was found to be 12-14% lower than the real situation. This study suggests that the exposure assessment is valuable in evaluating the health effects among the foundry workers, despite some limitations such as underestimation of exposure assessment and the lack of data regarding smoking and drinking habits.

  16. A novel strategy for retrospective exposure assessment in the Norwegian silicon carbide industry.

    PubMed

    Føreland, Solveig; Bugge, Merete Drevvatne; Bakke, Berit; Bye, Erik; Eduard, Wijnand

    2012-01-01

    The objective was to construct a retrospective job-exposure matrix (JEM) for the Norwegian silicon carbide industry. More than 3300 historical total dust measurements were available (1967-2005); however, there were few measurements of other agents. Total dust measurements were therefore used as the basis for the JEM, and a novel method was developed to estimate exposure to other agents. Multiple linear regression models were developed to describe historical exposure to total dust. Exposure estimates were extrapolated backward to periods without exposure data by adjustments for process and work-hour related changes. An exposure assessment study was performed where total dust was sampled in parallel with fibers or respirable dust. The respirable dust was analyzed for the content of quartz, cristobalite, and silicon carbide. Mixed-effect models were developed to estimate the exposure to these agents from total dust exposure, plant, and job group. Exposure to asbestos and polycyclic aromatic hydrocarbons was assigned qualitatively. Multiple linear regression models of total dust described historical exposure best in the furnace department (R(2) (adj) = 0.49-0.74). Models in the other departments explained less variance (R(2) (adj) = 0.12-0.32). Exposure determinants and total dust explained a substantial proportion of the between- (70-100%) and within-worker (8.0-54%) variance in the mixed-effect models. The relative bias between available historical measurements and the estimated exposure to dust components varied between -39% (fiber) and 40% (quartz). However, corrections were not considered necessary due to limitations in the historical data. The component-specific metrices were sufficiently different from each other (r(Pearson) < 0.7), with the exception of total and respirable dust (r(Pearson) = 0.84) and total dust and cristobalite (r(Pearson) = 0.72), and will enable component-specific epidemiologic analyses in the future. Improved and less correlated estimates

  17. Exposure assessment of workplace manufacturing titanium dioxide particles

    NASA Astrophysics Data System (ADS)

    Xu, Huadong; Zhao, Lin; Chen, Zhangjian; Zhou, Jingwen; Tang, Shichuan; Kong, Fanling; Li, Xinwei; Yan, Ling; Zhang, Ji; Jia, Guang

    2016-10-01

    With the widespread use of titanium dioxide (TiO2) human exposure is inevitable, but the exposure data on TiO2 are still limited. This study adopted off-line filter-based sampling combined with real-time activity-based monitoring to measure the concentrations in a workplace manufacturing TiO2 (primary diameter: 194 ± 108 nm). Mass concentrations (MCs) of aerosol particles in the packaging workshop (total dust: 3.17 mg/m3, nano dust: 1.22 mg/m3) were much higher than those in the milling workshop (total dust: 0.79 mg/m3, nano dust: 0.31 mg/m3) and executive office (total dust: 0.44 mg/m3, nano dust: 0.19 mg/m3). However, the MCs of TiO2 were at a relatively low level in the packaging workshop (total TiO2: 46.4 μg/m3, nano TiO2: 16.7 μg/m3) and milling workshop (total TiO2: 39.4 μg/m3, nano TiO2: 19.4 μg/m3) by ICP-MS. The number concentration (NC), surface area concentration (SAC) of aerosol particles potentially deposited in alveolar (SACA), and tracheobronchial (SACTB) regions of lungs in the packaging workshop were (1.04 ± 0.89) × 105 particles/cm3, 414.49 ± 395.07, and 86.01 ± 83.18 μm2/cm3, respectively, which were all significantly higher than those of the milling workshop [(0.12 ± 0.40) × 105 particles/cm3, 75.38 ± 45.23, and 17.60 ± 9.22 μm2/cm3, respectively] as well as executive office and outdoor background ( p < 0.05). Activity-related characteristics were found in both workshops, and the time-variant characteristics showed very similar trends for 3 days in the packaging workshop. Our study provides important data of TiO2 particles exposure in the workplace.

  18. Dose assessment of an accidental exposure at the IPNS

    SciTech Connect

    Campos Torres, M.M.

    1995-02-01

    Seven different methods were used to estimate the dose rate to a female worker who was accidentally exposed in the neutron PHOENIX beamline at the IPNS. Theoretical and measured entrance dose ranged from 550 mrem/min to 2850 mrem/min. Theoretical estimates were based on a Monte Carlo simulation of a spectrum provided by IPNS (Crawford Spectrum). Dose measurements were made with TLDs on phantoms and with ionization chambers in a water phantom. Estimates of the whole body total effective dose equivalent (TEDE) rate ranged from 5.2 mrem/min to 840 mrem/min. Assumed and measured quality factors ranged from 2.6 to 11.8. Cytogenetic analyses of blood samples detected no positive exposure. The recommended TEDE rate was 158 mrem/min. The TEDE was 750 mrem.

  19. [Risk assessment of lead exposure from different intake pathways for children in Wuhan City].

    PubMed

    Hao, Han-Zhou; Chen, Tong-Bin; Wu, Ji-Liang; Lei, Mei; Tian, Hui; Zu, Wen-Pu; Zhong, Xue-Bin

    2012-06-01

    70 sampling points were set in Wuhan City to collect soil, dust, air and food samples. According to the U. S. EPA recommended childhood lead exposure parameters, U. S. EPA human exposure risk assessment method was used to assess the potential health risk of different pathway exposures of children in Wuhan City to lead. The results of calculation show: Wuhan urban children's daily lead exposure is 1.20 x 10(-3) mg x (kg x d)(-1). The digestive tract is the main way for children's exposure to lead, with the exposure of 1.04 x 10(-3) mg x (kg x d)(-1), followed by the respiratory route and dermal absorption route, the exposures were 0.153 x 10(-3) mg x (kg x d)(-1) and 8.56 x 10(-7) mg x (kg x d)(-1) respectively. Pathways of the digestive tract, ingestion of soil or dust lead exposure accounted for 52.0% of the total exposure, through the digestive tract of soil or dust ingestion is the main route of exposure. Monte-Carlo method was used to simulate the pathway in the digestive tract, the amount of lead exposure through ingestion of soil was 2. 48 x 10(-2) mg x d(-1). The probability that exceeded the PTDI (Provisional Tolerable Daily Intake) specified by JECFA (The Joint FAO/WHO Expert Committee on Food Additives) was 2.1%. The results of the risk assessment indicate that lead exposure risks from the digestive tract, respiratory tract, skin absorption are less than the maximum acceptable risk level 5.0 x 10(-5) respectively and the risk associated with skin absorption of lead is less than the negligible risk level 1 x 10(-8). Application of Kriging interpolation method, Wuhan City children lead exposure value on spatial distribution were obtained, and Qingshan district and Jiangan district have a high level of children lead exposure. The aggregate risk index of Wuhan City children lead exposure was yield by using the indicator Kriging.

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

    PubMed

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

    2016-11-01

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

  1. Using Geographic Information Systems for Exposure Assessment in Environmental Epidemiology Studies

    PubMed Central

    Nuckols, John R.; Ward, Mary H.; Jarup, Lars

    2004-01-01

    Geographic information systems (GIS) are being used with increasing frequency in environmental epidemiology studies. Reported applications include locating the study population by geocoding addresses (assigning mapping coordinates), using proximity analysis of contaminant source as a surrogate for exposure, and integrating environmental monitoring data into the analysis of the health outcomes. Although most of these studies have been ecologic in design, some have used GIS in estimating environmental levels of a contaminant at the individual level and to design exposure metrics for use in epidemiologic studies. In this article we discuss fundamentals of three scientific disciplines instrumental to using GIS in exposure assessment for epidemiologic studies: geospatial science, environmental science, and epidemiology. We also explore how a GIS can be used to accomplish several steps in the exposure assessment process. These steps include defining the study population, identifying source and potential routes of exposure, estimating environmental levels of target contaminants, and estimating personal exposures. We present and discuss examples for the first three steps. We discuss potential use of GIS and global positioning systems (GPS) in the last step. On the basis of our findings, we conclude that the use of GIS in exposure assessment for environmental epidemiology studies is not only feasible but can enhance the understanding of the association between contaminants in our environment and disease. PMID:15198921

  2. Assessment of exposure to chemical agents and ergonomic stressors in tanneries in Kanpur, India.

    PubMed

    Ory, F G; Rahman, F U; Katagade, V; Shukla, A; Burdorf, A

    1997-10-01

    In developing countries qualitative assessment of exposure at the workplace may be an essential tool in evaluating hazardous working conditions. This survey reports on qualitative assessment of exposure to chemicals, dust, and ergonomic stressors among 298 workers in 15 tanneries in Kanpur, India. In general, chemical exposure and dermal exposure were highest among beamhouse workers, less for workers involved in dry finishing activities, and lowest for those performing the wet finishing of hides. Dermal exposure was rated as high to very high during beamhouse activities, reflecting direct contact with wet hides and manual handling of hides in soak tanks. Relevant dust exposure was observed only during dry finishing activities. Most workers experienced severe postural load due to working in trunk flexion and rotation for more than 50% of their daily work time. In addition, manual materials handling with loads over 20 kg frequently occurred. The size of the tannery, in general a reflection of state of technology, showed no systematic influence on exposure profiles. The survey suggested that mechanization of material transfer and application of trolleys reduced the work time with trunk flexion and rotation and implied less manual lifting. The presence of local exhaust ventilation in large tanneries seemed to reduce the chemical exposure. This survey has demonstrated the importance of rapid appraisal techniques for evaluating hazardous conditions at the workplace. In developing countries this approach may facilitate occupational hygiene research and practice.

  3. A Review of Exposure Assessment Methods in Epidemiological Studies on Incinerators

    PubMed Central

    Ranzi, Andrea; De Leo, Giulio A.; Lauriola, Paolo

    2013-01-01

    Incineration is a common technology for waste disposal, and there is public concern for the health impact deriving from incinerators. Poor exposure assessment has been claimed as one of the main causes of inconsistency in the epidemiological literature. We reviewed 41 studies on incinerators published between 1984 and January 2013 and classified them on the basis of exposure assessment approach. Moreover, we performed a simulation study to explore how the different exposure metrics may influence the exposure levels used in epidemiological studies. 19 studies used linear distance as a measure of exposure to incinerators, 11 studies atmospheric dispersion models, and the remaining 11 studies a qualitative variable such as presence/absence of the source. All reviewed studies utilized residence as a proxy for population exposure, although residence location was evaluated with different precision (e.g., municipality, census block, or exact address). Only one study reconstructed temporal variability in exposure. Our simulation study showed a notable degree of exposure misclassification caused by the use of distance compared to dispersion modelling. We suggest that future studies (i) make full use of pollution dispersion models; (ii) localize population on a fine-scale; and (iii) explicitly account for the presence of potential environmental and socioeconomic confounding. PMID:23840228

  4. Exposure assessment for a large epidemiological study of aircraft manufacturing workers.

    PubMed

    Marano, D E; Boice, J D; Fryzek, J P; Morrison, J A; Sadler, C J; McLaughlin, J K

    2000-08-01

    Methods were developed to assess exposure to a wide variety of chemicals for nearly 80,000 workers involved in manufacturing aircraft since 1928. The facilities, now closed, consisted of four major plants, over 200 buildings, and a changing workforce during 60 years of operation. To access chemical exposures by specific jobs and calendar years, we reviewed complete work histories, examined detailed job descriptions available going back to 1940, interviewed long-term employees, conducted walk-through visits of aircraft manufacturing plants, reviewed comprehensive environmental assessment reports and industrial hygiene surveys on the facilities, and built on experience gained in previous studies of the aircraft industry. Using computer-based imaging systems, we examined and evaluated the complete work histories found on service record cards for the cohort and abstracted detailed information on all jobs held among the factory workers who had been employed for at least one year. Jobs were classified into one of three exposure categories related to the use of specific chemicals: routine, intermittent, and none, and these classifications were subsequently used in the epidemiological analyses. The approach to exposure assessment began with the most general categorization of employees (i.e., all workers) and then became progressively more specific, that is, factor workers, job families (similar activities), job titles, and jobs with chemical usage (exposure potential). Because exposure surveys were limited or absent during the early years of plant operations, we did not assign quantitative measures of exposure to individual job activities. Instead, we used as our exposure metric, the length of time spent in jobs with potential exposure to the chemical. Important occupational exposures included chromate-containing compounds such as used in paint primers, trichloroethylene and perchloroethylene used as vapor-state degreasing solvents, and a broad range of other solvents.

  5. Indoor aerosol modeling for assessment of exposure and respiratory tract deposited dose

    NASA Astrophysics Data System (ADS)

    Hussein, Tareq; Wierzbicka, Aneta; Löndahl, Jakob; Lazaridis, Mihalis; Hänninen, Otto

    2015-04-01

    Air pollution is one of the major environmental problems that influence people's health. Exposure to harmful particulate matter (PM) occurs both outdoors and indoors, but while people spend most of their time indoors, the indoor exposures tend to dominate. Moreover, higher PM concentrations due to indoor sources and tightness of indoor environments may substantially add to the outdoor originating exposures. Empirical and real-time assessment of human exposure is often impossible; therefore, indoor aerosol modeling (IAM) can be used as a superior method in exposure and health effects studies. This paper presents a simple approach in combining available aerosol-based modeling techniques to evaluate the real-time exposure and respiratory tract deposited dose based on particle size. Our simple approach consists of outdoor aerosol data base, IAM simulations, time-activity pattern data-base, physical-chemical properties of inhaled aerosols, and semi-empirical deposition fraction of aerosols in the respiratory tract. These modeling techniques allow the characterization of regional deposited dose in any metric: particle mass, particle number, and surface area. The first part of this presentation reviews recent advances in simple mass-balance based modeling methods that are needed in analyzing the health relevance of indoor exposures. The second part illustrates the use of IAM in the calculations of exposure and deposited dose. Contrary to previous methods, the approach presented is a real-time approach and it goes beyond the exposure assessment to provide the required information for the health risk assessment, which is the respiratory tract deposited dose. This simplified approach is foreseen to support epidemiological studies focusing on exposures originating from both indoor and outdoor sources.

  6. Public health risk from ELF (electromagnetic fields) exposure -- can it be assessed

    SciTech Connect

    Aldrich, T.E.; Easterly, C.E.

    1988-01-01

    Extremely low frequency electromagnetic fields (ELF) are a ubiquitous environmental agent. There are persistent indications that these fields have biologic activity, and consequently, there may be a deleterious component to their action. Epidemiologic researchers of ELF face several methodological obstacles, and quantitative risk assessment is in a quandary. Simply stated there is a need for more data---especially with regard to exposure assessment.

  7. Health Risk Assessment of Inhalation Exposure to Formaldehyde and Benzene in Newly Remodeled Buildings, Beijing

    PubMed Central

    Huang, Lihui; Mo, Jinhan; Sundell, Jan; Fan, Zhihua; Zhang, Yinping

    2013-01-01

    Objective To assess health risks associated with inhalation exposure to formaldehyde and benzene mainly emitted from building and decoration materials in newly remodeled indoor spaces in Beijing. Methods We tested the formaldehyde and benzene concentrations in indoor air of 410 dwellings and 451 offices remodeled within the past year, in which the occupants had health concerns about indoor air quality. To assess non-carcinogenic health risks, we compared the data to the health guidelines in China and USA, respectively. To assess carcinogenic health risks, we first modeled indoor personal exposure to formaldehyde and benzene using the concentration data, and then estimated the associated cancer risks by multiplying the indoor personal exposure by the Inhalation Unit Risk values (IURs) provided by the U.S. EPA Integrated Risk Information System (U.S. EPA IRIS) and the California Office of Environmental Health Hazard Assessment (OEHHA), respectively. Results (1) The indoor formaldehyde concentrations of 85% dwellings and 67% offices were above the acute Reference Exposure Level (REL) recommended by the OEHHA and the concentrations of all tested buildings were above the chronic REL recommended by the OEHHA; (2) The indoor benzene concentrations of 12% dwellings and 32% offices exceeded the reference concentration (RfC) recommended by the U.S. EPA IRIS; (3) The median cancer risks from indoor exposure to formaldehyde and benzene were 1,150 and 106 per million (based on U.S. EPA IRIS IURs), 531 and 394 per million (based on OEHHA IURs). Conclusions In the tested buildings, formaldehyde exposure may pose acute and chronic non-carcinogenic health risks to the occupants, whereas benzene exposure may pose chronic non-carcinogenic risks to the occupants. Exposure to both compounds is associated with significant carcinogenic risks. Improvement in ventilation, establishment of volatile organic compounds (VOCs) emission labeling systems for decorating and refurbishing materials

  8. Incorporating exposure science into life-cycle assessment

    EPA Science Inventory

    Life-cycle assessment (LCA) is used to estimate the potential for environmental damage that may be caused by a product or process, ideally before the product or process begins. LCA includes all of the steps from extracting natural resources through manufacturing through product u...

  9. Exposure as Part of a Systems Approach for Assessing Risk

    EPA Science Inventory

    The U.S. Environmental Protection Agency is facing large challenges in managing environmental chemicals with increasingly complex requirements for assessing risk that push the limits of our current approaches. To address some of these challenges, the National Research Council (NR...

  10. The Health Impacts of Energy Policy Pathways in Ulaanbaatar, Mongolia: A Total Exposure Assessment

    NASA Astrophysics Data System (ADS)

    Hill, L. A.; Damdinsuren, Y.; Olkhanud, P. B.; Smith, K. R.; Turner, J. R.; Edwards, R.; Odsuren, M.; Ochir, C.

    2015-12-01

    Ulaanbaatar is home to nearly half of Mongolia's 2.8 million residents. The city's rapid growth, frigid winters, valley topography, and reliance on coal-fired stoves have led to some of the worst winter pollution levels in the world. To better understand this issue, we modeled integrated PM2.5exposures and related health impacts for various city-wide heating policies through 2024. This assessment is one of the first to employ a total exposure approach and results of the 2014 Comparative Risk Assessments of the Global Burden of Disease Project (CRA/GBD) in a policy-relevant energy study. Emissions related to heating, traffic, and power generation were considered under Business as Usual, Moderate Improvement, and Max Improvement scenarios. Calibrated outdoor models were combined with indoor models, local infiltration and time activity estimates, and demographic projections to estimate PM2.5exposures in 2014 and 2024. Indoor exposures were assigned by heating type, home type, and smoking status; outdoor exposures were assigned through geocoding. Population average annual exposures were calculated and applied to local disease rates and integrated exposure-response curves (2014 CRA/GBD) to arrive at annual projections of premature deaths and DALYs. We estimate 2014 annual average exposures at 68 μg/m3, dictated almost exclusively by indoor winter exposures. Under current trends, annual exposures increase 10% to 75 μg/m3 in 2024. This is in stark contrast to the moderate and max improvement scenarios, which lead to 2024 annual exposures that are 31%, and 68% lower, respectively. Under the Moderate scenario, 2024 per capita annual DALY and death burdens drop 26% and 22%, respectively, from 2014 levels. Under the Max scenario, 2024 per capita annual DALY and death burdens drop 71% and 66%, respectively, from 2014. SHS becomes a major contributor as emissions from other sectors decrease. Reductions are dominated by cardiovascular and lower respiratory diseases in children.

  11. 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.

  12. Aggregate versus Individual-Level Sexual Behavior Assessment: How Much Detail Is Needed to Accurately Estimate HIV/STI Risk?

    ERIC Educational Resources Information Center

    Pinkerton, Steven D.; Galletly, Carol L.; McAuliffe, Timothy L.; DiFranceisco, Wayne; Raymond, H. Fisher; Chesson, Harrell W.

    2010-01-01

    The sexual behaviors of HIV/sexually transmitted infection (STI) prevention intervention participants can be assessed on a partner-by-partner basis: in aggregate (i.e., total numbers of sex acts, collapsed across partners) or using a combination of these two methods (e.g., assessing five partners in detail and any remaining partners in aggregate).…

  13. Assessing exposure to granite countertops--Part 2: Radon.

    PubMed

    Allen, Joseph G; Minegishi, Taeko; Myatt, Theodore A; Stewart, James H; McCarthy, John F; Macintosh, David L

    2010-05-01

    Radon gas ((222)Rn) is a natural constituent of the environment and a risk factor for lung cancer that we are exposed to as a result of radioactive decay of radium ((226)Ra) in stone and soil. Granite countertops, in particular, have received recent media attention regarding their potential to emit radon. Radon flux was measured on 39 full slabs of granite from 27 different varieties to evaluate the potential for exposure and examine determinants of radon flux. Flux was measured at up to six pre-selected locations on each slab and also at areas identified as potentially enriched after a full-slab scan using a Geiger-Muller detector. Predicted indoor radon concentrations were estimated from the measured radon flux using the CONTAM indoor air quality model. Whole-slab average emissions ranged from less than limit of detection to 79.4 Bq/m(2)/h (median 3.9 Bq/m(2)/h), similar to the range reported in the literature for convenience samples of small granite pieces. Modeled indoor radon concentrations were less than the average outdoor radon concentration (14.8 Bq/m(3); 0.4 pCi/l) and average indoor radon concentrations (48 Bq/m(3); 1.3 pCi/l) found in the United States. Significant within-slab variability was observed for stones on the higher end of whole slab radon emissions, underscoring the limitations of drawing conclusions from discrete samples.

  14. Assessment of Turkish junior male physicians’ exposure to mobbing behavior

    PubMed Central

    Sahin, Bayram; Cetin, Mehmet; Cimen, Mesut; Yildiran, Nuri

    2012-01-01

    Aim To determine the extent of Turkish junior male physicians’ exposure to mobbing behavior and its correlation with physicians' characteristics. Methods The study included physicians recruited for compulsory military service in April 2009. No sampling method was used, questionnaires were delivered to all physicians, and 278 of 292 (95%) questionnaires were returned. We used Leymann Inventory of Psychological Terror including 45 items for data collection and structural equation model for data analysis. Results A total of 87.7% of physicians experienced mobbing behavior. Physicians who worked more than 40 hours a week, single physicians, physicians working in university hospitals and private hospitals, and physicians who did not have occupational commitment were more exposed to mobbing (P < 0.05). Mobbing was not associated with specialty status, service period, age, and personality variables (P > 0.05). All goodness-of- fit indices of the model were acceptable (χ2 = 1.449, normed fit index = 0.955, Tucker Lewis index = 0.980, comparative fit index = 0.985, and root mean square error of approximation = 0.040). Conclusions Workplace mobbing is a critical problem for junior male physicians in Turkey. We suggest an introduction of a reporting system and education activities for physicians in high-risk groups. PMID:22911529

  15. Aflatoxins in hazelnuts and dried figs: Occurrence and exposure assessment.

    PubMed

    Kabak, Bulent

    2016-11-15

    A total of 300 samples of hazelnuts and dried fig were analysed for the incidence of any aflatoxins (AFs). High-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method was used to quantify the amounts of AFs. The limit of quantification varied from 0.21 to 0.30μgkg(-1). No AFs were detected in shells of the hazelnuts, while six raw hazelnut kernel samples (12%) and five roasted hazelnut kernel samples (8.3%) contained AFs ranging from 0.09 to 11.3μgkg(-1) and from 0.17 to 11.2μgkg(-1), respectively. Sixteen dried fig samples (12.3%) contained AFs ranging from 0.1 to 28.2μgkg(-1) and a mean value of 3.8μgkg(-1). Three hazelnuts and six dried fig samples exceeded the European maximum limits (MLs) of 5 and 2μgkg(-1) for aflatoxin B1 (AFB1), respectively. The contribution of hazelnuts to AFs exposure is higher than that of dried figs.

  16. Occupational Exposure to Mercury: Air Exposure Assessment and Biological Monitoring based on Dispersive Ionic Liquid-Liquid Microextraction

    PubMed Central

    SHIRKHANLOO, Hamid; GOLBABAEI, Farideh; HASSANI, Hamid; EFTEKHAR, Farrokh; KIAN, Mohammad Javad

    2014-01-01

    Abstract Background Exposure to mercury (Hg) as a heavy metal can cause health effects. The objective of this study was to assess occupational exposure to Hg in a chlor-alkali petrochemical industry in Iran by determining of Hg concentrations in air, blood and urine samples. Methods The study was performed on 50 exposed subjects and 50 unexposed controls. Air samples were collected in the breathing zone of exposed subjects, using hopcalite sorbents. Analysis was performed using a cold vapor atomic absorption spectrophotometer (CV-AAS) according to NIOSH analytical method 6009. For all participants, blood and urine samples were collected and then transferred into sterile glass tubes. After micro-extraction with ionic liquid and back extraction with nitric acid, Hg concentrations in blood and urine samples were determined by CV-AAS. Results The mean concentration of air Hg was 0.042± 0.003 mg/m3. The mean concentrations of Hg in blood and urine samples of exposed subjects were significantly higher than unexposed controls (22.41± 12.58 versus 1.19± 0.95 μg/l and 30.61± 10.86 versus 1.99± 1.34 μg/g creatinine, respectively). Correlation of air Hg with blood Hg, urine Hg and blood Hg-urine Hg ratio were significant statistically (P< 0.05). Conclusions The values of Hg in blood and urine samples of chlor-alkali workers were considerably high. Correlation coefficients showed that blood Hg and blood Hg-urine Hg ratio are better indicators than urine Hg for assessing occupationally exposed workers in terms of current exposure assessment. PMID:26110150

  17. A review of air exchange rate models for air pollution exposure assessments.

    PubMed

    Breen, Michael S; Schultz, Bradley D; Sohn, Michael D; Long, Thomas; Langstaff, John; Williams, Ronald; Isaacs, Kristin; Meng, Qing Yu; Stallings, Casson; Smith, Luther

    2014-11-01

    A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings where people spend their time. The AER, which is the rate of exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pollutants and for removal of indoor-emitted air pollutants. This paper presents an overview and critical analysis of the scientific literature on empirical and physically based AER models for residential and commercial buildings; the models highlighted here are feasible for exposure assessments as extensive inputs are not required. Models are included for the three types of airflows that can occur across building envelopes: leakage, natural ventilation, and mechanical ventilation. Guidance is provided to select the preferable AER model based on available data, desired temporal resolution, types of airflows, and types of buildings included in the exposure assessment. For exposure assessments with some limited building leakage or AER measurements, strategies are described to reduce AER model uncertainty. This review will facilitate the selection of AER models in support of air pollution exposure assessments.

  18. [Predictive models for the assessment of occupational exposure to chemicals: a new challenge for employers].

    PubMed

    Gromiec, Jan Piotr; Kupczewska-Dobecka, Małgorzata; Jankowska, Agnieszka; Czerczak, Sławomir

    2013-01-01

    Employers are obliged to carry out and document the risk associated with the use of chemical substances. The best but the most expensive method is to measure workplace concentrations of chemicals. At present no "measureless" method for risk assessment is available in Poland, but predictive models for such assessments have been developed in some countries. The purpose of this work is to review and evaluate the applicability of selected predictive methods for assessing occupational inhalation exposure and related risk to check the compliance with Occupational Exposure Limits (OELs), as well as the compliance with REACH obligations. Based on the literature data HSE COSHH Essentials, EASE, ECETOC TRA, Stoffenmanager, and EMKG-Expo-Tool were evaluated. The data on validation of predictive models were also examined. It seems that predictive models may be used as a useful method for Tier 1 assessment of occupational exposure by inhalation. Since the levels of exposure are frequently overestimated, they should be considered as "rational worst cases" for selection of proper control measures. Bearing in mind that the number of available exposure scenarios and PROC categories is limited, further validation by field surveys is highly recommended. Predictive models may serve as a good tool for preliminary risk assessment and selection of the most appropriate risk control measures in Polish small and medium size enterprises (SMEs) providing that they are available in the Polish language. This also requires an extensive training of their future users.

  19. Assessing unregulated ionizing radiation exposures of U.S. populations from conventional industries.

    PubMed

    Pennington, Charles W

    2006-08-15

    During the latter twentieth century, the public learned to fear perceived threats from emerging technologies. Concern about ionizing radiation became a persistent fear, causing protracted and often pointless debate. The twenty-first century offers new opportunities for this fear to cause public and political upset. Citizens and politicians know little about "normal" radiation exposures caused by conventional industries. This paper summarizes ionizing radiation exposure assessments of several such industries, showing they deliver multiples of background radiation annually to millions of people, with even higher subpopulation doses due to lognormally distributed exposures. Such information may be useful in educating the public and in supporting comparative assessments or other forms of research on potential sources of public radiation exposure in the twenty-first century. By exposing people to information about normal radiation, we may hope to avoid some unfortunate policies and unnecessary regulatory responses, while abating needless public fear during this technologically challenging century.

  20. Evaluating the Control Banding Nanotool: a qualitative risk assessment method for controlling nanoparticle exposures

    NASA Astrophysics Data System (ADS)

    Zalk, David M.; Paik, Samuel Y.; Swuste, Paul

    2009-10-01

    Control banding (CB) strategies offer simplified processes for controlling worker exposures in the absence of firm toxicological and exposure information. The nanotechnology industry is an excellent candidate for applying such strategies with overwhelming uncertainties of work-related health risks posed by nanomaterials. A recent survey shows that a majority of nanomaterial producers are not performing a basic risk assessment of their product in use. The CB Nanotool, used internationally, was developed to conduct qualitative risk assessments to control nanoparticle exposures. Nanotoxicology experts have requested standardization of toxicological parameters to ensure better utility and consistency of research. Such standardization would fit well in the CB Nanotool's severity and probability risk matrix, therefore enhancing the protection of nanotechnology industry workers. This article further evaluates the CB Nanotool for structure, weighting of risk factors, and utility for exposure mitigation, and suggests improvements for the CB Nanotool and the research needed to bolster its effectiveness.

  1. A novel method to assess human population exposure induced by a wireless cellular network.

    PubMed

    Varsier, Nadège; Plets, David; Corre, Yoann; Vermeeren, Günter; Joseph, Wout; Aerts, Sam; Martens, Luc; Wiart, Joe

    2015-09-01

    This paper presents a new metric to evaluate electromagnetic exposure induced by wireless cellular networks. This metric takes into account the exposure induced by base station antennas as well as exposure induced by wireless devices to evaluate average global exposure of the population in a specific geographical area. The paper first explains the concept and gives the formulation of the Exposure Index (EI). Then, the EI computation is illustrated through simple phone call scenarios (indoor office, in train) and a complete macro urban data long-term evolution scenario showing how, based on simulations, radio-planning predictions, realistic population statistics, user traffic data, and specific absorption rate calculations can be combined to assess the index. Bioelectromagnetics. 36:451-463, 2015. © 2015 Wiley Periodicals, Inc.

  2. EPHECT III: Health risk assessment of exposure to household consumer products.

    PubMed

    Trantallidi, M; Dimitroulopoulou, C; Wolkoff, P; Kephalopoulos, S; Carrer, P

    2015-12-01

    In the framework of the EU EPHECT project (Emissions, Exposure Patterns and Health Effects of Consumer Products in the EU), irritative and respiratory effects were assessed in relation to acute (30-min) and long-term (24-h) inhalation exposure to key and emerging indoor air pollutants emitted during household use of selected consumer products. A detailed Health Risk Assessment (HRA) was performed for five selected pollutants of respiratory health relevance, namely acrolein, formaldehyde, naphthalene, d-limonene and α-pinene. For each pollutant, the Critical Exposure Limit (CEL) was compared to indoor air concentrations and exposure estimates for the use of 15 selected consumer products by two population groups (housekeepers and retired people) in the four geographical regions of Europe (North, West, South, East), which were derived previously based on microenvironmental modelling. For the present HRA, health-based CELs were derived for certain compounds in case indoor air quality guidelines were not available by the World Health Organization for end-points relevant to the current study. For each pollutant, the highest indoor air concentrations in each microenvironment and exposure estimates across home microenvironments during the day were lower than the corresponding acute and long-term CELs. However, considerable contributions, especially to acute exposures, were obtained in some cases, such as formaldehyde emissions resulting from single product use of a floor cleaning agent (82% CEL), a candle (10% CEL) and an electric air freshener (17% CEL). Regarding multiple product use, the case of 30-min formaldehyde exposure reaching 34% CEL when eight product classes were used across home microenvironments, i.e. all-purpose/kitchen/floor cleaning agents, furniture/floor polish, combustible/electric air fresheners, and perfume, needs to be highlighted. Such estimated values should be evaluated with caution, as these may be attributed to the exposure scenarios

  3. The use of exposure source allocation factor in the risk assessment of drinking-water contaminants.

    PubMed

    Krishnan, Kannan; Carrier, Richard

    2013-01-01

    In the risk assessment process, the reference dose, tolerable intake, or acceptable daily intake (RfD, TDI, ADI) is apportioned to specific exposure sources on the basis of a source allocation factor (AF) or relative source contribution (RSC). The U.S. Environmental Protection Agency (EPA) published an exposure decision tree framework in 2000 to guide the determination of AF (or RSC) of drinking-water contaminants (DWC). Besides that, there has not been any systematic analysis of the basis of the use of AF in DWC risk assessments. This article therefore critically reviews and integrates current knowledge and approaches for the development of AF, while focusing on its consistent use in DWC risk assessments based on consideration of (i) risk assessment endpoint, (ii) existing guidelines, (iii) exposure estimates, (iv) usage pattern and environmental fate information, (v) physicochemical properties, (vi) bounds of AF