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Sample records for retrospective exposure assessment

  1. Exposure assessment in industry specific retrospective occupational epidemiology studies.

    PubMed Central

    Seixas, N S; Checkoway, H

    1995-01-01

    Quantitative estimation of exposure for occupational epidemiology studies has received increasing attention in recent years and, as a result, a body of methodological literature has begun to take form. This paper reviews the generic issues in the methodology of exposure assessment, particularly methods for quantitative retrospective assessment studies. A simple framework, termed an exposure data matrix (EDM), for defining and analysing exposure data is proposed and discussed in terms of the definition of matrix dimensions and scales. Several methods for estimation, interpolation, and extrapolation, ranging from subjective ratings to quantitative statistical modelling are presented and discussed. The various approaches to exposure assessment based on the EDM concept are illustrated with studies of lung disease among coal miners and other dust and chemically induced chronic occupational diseases. The advantages of validated statistical models are emphasised. The importance of analysis and control of errors in exposure assessments, and integration of the exposure assessment and exposure-response processes, especially for emerging occupational health issues, is emphasised. PMID:7489051

  2. 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

  3. 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. PMID:16981402

  4. Retrospective Assessment of Exposure to Chemicals for a Microelectronics and Business Machine Manufacturing Facility

    PubMed Central

    Fleming, Donald A.; Woskie, Susan R.; Jones, James H.; Silver, Sharon R.; Luo, Lian; Bertke, Stephen J.

    2015-01-01

    A retrospective exposure assessment was performed for use in a health outcomes study of a facility manufacturing circuit boards, business machines, and other equipment during the years 1969–2002. A matrix was developed identifying chemical use by department-year based on company-provided information. Use of six chemical agents (fiberglass, lead, methylene chloride, methyl chloroform, perchloroethylene, and trichloroethylene) and six chemical classes (acid-base, aromatic hydrocarbons, chlorinated hydrocarbons, other hydrocarbons, chlorofluorocarbons, and metals), and general (including unspecified) chemicals was identified. The matrix also contained an assignment for each department-year categorizing the potential for use of chemicals as negligible, intermittent/incidental, or routine. These department-based exposure matrix data were combined with work history data to provide duration of potential chemical use for workers. Negligible, intermittent/incidental or routine extent-of-chemical-use categories comprised 42.6%, 39.4%, and 17.9%, respectively, of total person-years of employment. Cumulative exposure scores were also developed, representing a relative measure of the cumulative extent of potential exposure to the six chemical agents, six chemical classes, and general (including unspecified) chemicals. Additionally, the study period was divided into manufacturing eras showing trends in chemical use, and showing that process use of trichloroethylene and methylene chloride ended in the mid-1980s and the mid-1990s, respectively. This approach may be useful in other assessments addressing a variety of chemicals, and with data constraints common to retrospective chemical exposure studies. PMID:24224613

  5. Retrospective assessment of exposure to chemicals for a microelectronics and business machine manufacturing facility.

    PubMed

    Fleming, Donald A; Woskie, Susan R; Jones, James H; Silver, Sharon R; Luo, Lian; Bertke, Stephen J

    2014-01-01

    A retrospective exposure assessment was performed for use in a health outcomes study of a facility manufacturing circuit boards, business machines, and other equipment during the years 1969-2002. A matrix was developed identifying chemical use by department-year based on company-provided information. Use of six chemical agents (fiberglass, lead, methylene chloride, methyl chloroform, perchloroethylene, and trichloroethylene) and six chemical classes (acid-base, aromatic hydrocarbons, chlorinated hydrocarbons, other hydrocarbons, chlorofluorocarbons, and metals), and general (including unspecified) chemicals was identified. The matrix also contained an assignment for each department-year categorizing the potential for use of chemicals as negligible, intermittent/incidental, or routine. These department-based exposure matrix data were combined with work history data to provide duration of potential chemical use for workers. Negligible, intermittent/incidental or routine extent-of-chemical-use categories comprised 42.6%, 39.4%, and 17.9%, respectively, of total person-years of employment. Cumulative exposure scores were also developed, representing a relative measure of the cumulative extent of potential exposure to the six chemical agents, six chemical classes, and general (including unspecified) chemicals. Additionally, the study period was divided into manufacturing eras showing trends in chemical use, and showing that process use of trichloroethylene and methylene chloride ended in the mid-1980s and the mid-1990s, respectively. This approach may be useful in other assessments addressing a variety of chemicals, and with data constraints common to retrospective chemical exposure studies. PMID:24224613

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

    SciTech Connect

    Janeen Denise Robertson

    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.

  7. Exposure to o-toluidine, aniline, and nitrobenzene in a rubber chemical manufacturing plant: a retrospective exposure assessment update.

    PubMed

    Hanley, Kevin W; Viet, Susan M; Hein, Misty J; Carreón, Tania; Ruder, Avima M

    2012-01-01

    The National Institute for Occupational Safety and Health previously conducted a retrospective cancer incidence and mortality study of workers employed at a rubber chemical manufacturing plant. Compared with New York State incidence, the bladder cancer risk was 6.5 times higher for workers considered to have definite exposure to ortho-toluidine and aniline, and 4 times higher for workers with possible exposure. Exposure characterization in the original study utilized a surrogate measure based only on departments in which each worker was ever employed. As part of an update of that study, some departments in the three original exposure groups were reclassified based on a follow-up site visit; interviews with employees, management, and union representatives; and review of records including exposure data. An additional evaluation of department-job combinations, rather than only departments, was used to stratify exposure into four categories. An approximate rank of "relative" exposure level for each department-job-year combination was also assigned using a ranking scale of 0 to 10. The ranks were supported by quantitative exposure levels and by professional judgment. The numerical ranking scale was applied to each worker by multiplying the exposure rank by duration for each job held based on comprehensive individual work histories. The cumulative rank scores for this cohort ranged from 0 to 300 unit-years. The medians of the cumulative rank scores for the exposure categories showed very good agreement with increasing exposure classifications (e.g., 0.72, 4.6, 11, 14 unit-years for the four exposure categories). Workers' breathing zone air sampling data collected at this plant from 1976-2004 were well below published occupational exposure limits for these chemicals, but additional cases of bladder cancer have been reported. The exposure assessment revisions and rank estimates will be used to analyze the updated bladder cancer incidence data.

  8. A further study of the (CR LR) difference technique for retrospective radon exposure assessment

    NASA Astrophysics Data System (ADS)

    Nikezic, D.; Yip, C. W. Y.; Leung, S. Y. Y.; Leung, J. K. C.; Yu, K. N.

    2006-12-01

    The (CR-LR) difference technique, based on the CR-39 and LR 115 detectors, for the determination of implanted 210Po in glass after deposition of short-lived radon progeny, was analyzed in details in this paper. The sensitivities of both detectors were calculated using the Monte Carlo method with V functions particularly derived in our previous works for the detectors used in the present experiments. The dependency of the sensitivity ratio on the removed layer of both detectors was determined and verified experimentally. The simulated sensitivity ratios correlate well with the experimental ones. A major finding of the present work is that the sensitivity ratio between the CR-39 and LR 115 detectors depends only weakly on the ratio between the 238U and 232Th concentrations in the glass samples. This is crucial for the application of the (CR-LR) difference technique for retrospective radon exposure assessments, since measurements of the 238U and 232Th concentrations in the relatively small real-life glass samples will make the retrospective radon exposure assessments impractical.

  9. Optically Stimulated Luminescence (OSL) of dental enamel for retrospective assessment of radiation exposure

    PubMed Central

    Yukihara, E.G.; Mittani, J.; McKeever, S.W.S.; Simon, S.L.

    2009-01-01

    This paper briefly reviews the optically stimulated luminescence (OSL) properties of dental enamel and discusses the potential and challenges of OSL for filling the technology gap in biodosimetry required for medical triage following a radiological/nuclear accident or terrorist event. The OSL technique uses light to stimulate a radiation-induced luminescence signal from materials previously exposed to ionizing radiation. This luminescence originates from radiation-induced defects in insulating crystals and is proportional to the absorbed dose of ionizing radiation. In our research conducted to date, we focused on fundamental investigations of the OSL properties of dental enamel using extracted teeth and tabletop OSL readers. The objective was to obtain information to support the development of the necessary instrumentation for retrospective dosimetry using dental enamel in laboratory, or for in situ and non-invasive accident dosimetry using dental enamel in emergency triage. An OSL signal from human dental enamel was detected using blue, green, or IR stimulation. Blue/green stimulation associated with UV emission detection seems to be the most appropriate combination in the sense that there is no signal from un-irradiated samples and the shape of the OSL decay is clear. Improvements in the minimum detection level were achieved by incorporating an ellipsoidal mirror in the OSL system to maximize light collection. Other possibilities to improve the sensitivity and research steps necessary to establish the feasibility of the technique for retrospective assessment of radiation exposure are also discussed. PMID:19623269

  10. Retrospective assessment of indoor radon exposure by measurements of embedded 210Po activity in glass objects

    NASA Astrophysics Data System (ADS)

    Ramola, R. C.; Gusain, G. S.; Prasad, Ganesh

    In most of the epidemiological studies contemporary radon measurements have been used as surrogates for radon concentrations in past decades even though changes in radon levels and residence may have occurred. Short-lived radon progeny may deposit on available surfaces in dwellings thus giving rise over time to a build up of long-lived progeny. Airborne radon decay products can be deposited and implanted through alpha recoil into the glass surfaces. On glass surface, activities of 210Po may arise as a result of the decay of recoil implanted activity following the alpha decay of surface deposited 218Po or 214Po. Measurement of 210Po implanted on a household glass is a method that can be employed to retrospectively determine the historic level of radon in dwellings. This method is based on the assumption that levels of recoil implanted 210Po in the glass provide a measure of time integrated radon concentration in the environment in which the glass has been located. The surface deposited activity of the radon progenies, which then become implanted in the glass by alpha recoil, is believed to reflect past exposure to airborne activity. Such retrospective measurements on glass are valuable in estimating the human dose derived from radon during the time of exposure. In this paper an account is given of the principles and some field applications of a retrospective technique, using the alpha track detectors, CR-39 and LR-115, to measure 210Po implanted in glass surfaces (surface traps). By using this CR-LR difference technique, the cumulative radon exposure in a dwelling in past decades may be estimated. This method provides reliable radon exposure data as a support to epidemiological studies concerning the health effects of radon exposure in the living environment.

  11. A Retrospective Assessment of Occupational Exposure to Elemental Carbon in the U.S. Trucking Industry

    PubMed Central

    Hart, Jaime E.; Laden, Francine; Garshick, Eric; Smith, Thomas J.

    2011-01-01

    Background: Despite considerable epidemiologic evidence about the health effects of chronic exposure to vehicle exhaust, efforts at defining the extent of risk have been limited by the lack of historical exposure measurements suitable for use in epidemiologic studies and for risk assessment. Objectives: We sought to reconstruct exposure to elemental carbon (EC), a marker of diesel and other vehicle exhaust exposure, in a large national cohort of U.S. trucking industry workers. Methods: We identified the predictors of measured exposures based on a statistical model and used this information to extrapolate exposures across the cohort nationally. These estimates were adjusted for changes in work-related conditions over time based on a previous exposure assessment of this industry, and for changes in background levels based on a trend analysis of historical air pollution data, to derive monthly estimates of EC exposure for each job and trucking terminal combination between 1971 and 2000. Results: Occupational exposure to EC declined substantially over time, and we found significant variability in estimated exposures both within and across job groups, trucking terminals, and regions of the United States. Average estimated EC exposures during a typical work shift ranged from < 1 μg/m3 in the lowest exposed category in the 1990s to > 40 μg/m3 for workers in the highest exposed jobs in the 1970s. Conclusions: Our results provide a framework for understanding changes over time in exposure to EC in the U.S. trucking industry. Our assessment should minimize exposure misclassification by capturing variation among terminals and across U.S. regions, and changes over time. PMID:21447452

  12. Task- and time-dependent weighting factors in a retrospective exposure assessment of chemical laboratory workers.

    PubMed

    Henn, Scott A; Utterback, David F; Waters, Kathleen M; Markey, Andrea M; Tankersley, William G

    2007-02-01

    A chemical exposure assessment was conducted for a cohort mortality study of 6157 chemical laboratory workers employed between 1943 and 1998 at four Department of Energy sites in Oak Ridge, Tennessee, and Aiken, South Carolina. Previous studies of chemical laboratory workers have included members within professional societies where exposure assessment was either limited or not feasible, or chemical processing employees where laboratory and production workers were combined. Because sufficient industrial hygiene records were unavailable for all four sites, weighted duration of employment was used as a surrogate for the magnitude of exposure. Potential exposure indices were calculated for each worker using number of days employed and weighting factors for frequency of contact and year of employment. A total of 591 unique laboratory job titles indicative of a chemical laboratory worker were collapsed into 18 general job title categories. Through discussions with current and retired workers, along with examination of historical organizational charts and job descriptions, the percentage of time with activities involving the direct handling of chemicals in the laboratory was estimated for each job title category. Scaled weighting factors of 1, 0.6, 0.3, and 0.05 were assigned to the job title categories representing 100%, 60%, 30%, and 5% of daily activities handling chemicals, respectively. Based on limited industrial hygiene monitoring data, personal radiation monitoring records, and professional judgment, weighting factors that declined 4% annually were applied to each year to account for improvements in laboratory technique, advancements in instrumentation, improvement in engineering controls, and increased safety awareness through time. The study cohort was separated into three categories of chemical exposures based on department level information: (1) inorganic, (2) mixed inorganic and organic, and (3) unknown. Potential exposure indices ranged from 0.15 to 6824

  13. Task- and Time-Dependent Weighting Factors in a Retrospective Exposure Assessment of Chemical Laboratory Workers

    SciTech Connect

    Scott A. Henn, David F. Utterback, Kathleen M. Waters, Andrea M. Markey, William G. Tankersley

    2007-02-01

    Results are reported from a chemical exposure assessment that was conducted for a cohort mortality study of 6157 chemical laboratory workers employed between 1943 and 1998 at four Department of Energy sites in Oak Ridge, Tenn., and Aiken, S.C.

  14. A methodology for estimating human exposure to perfluorooctanoic acid (PFOA): a retrospective exposure assessment of a community (1951-2003).

    PubMed

    Paustenbach, Dennis J; Panko, Julie M; Scott, Paul K; Unice, Kenneth M

    2007-01-01

    Perfluorooctanoic acid (PFOA) is a persistent chemical that was recently shown to be widely distributed in the ambient environment. Because of concerns about the possible adverse health effects on persons exposed to PFOA, a retrospective exposure assessment was conducted for a population of about 50,000 persons who reside near one of the facilities where this chemical was used. No similar study of any chemical with the properties of PFOA had ever been performed; thus, several novel methods were developed and applied in this analysis. Historical records of the emissions from the facility were the basis for the estimates of the potential intake of (PFOA) by residents over the past 53 yr. Various well-accepted environmental models were dynamically combined in order to estimate the concentrations in all relevant environmental media including ambient air, surface soil, drinking water, and homegrown vegetables. Following considerable analyses, particulate deposition from facility air emissions to soil and the subsequent transfer of the chemical through the soil was determined to be the most likely source of PFOA that was detected in groundwater. The highest off-site environmental concentrations were predicted to occur about 1 mile away. For this approximately square mile area, during the time period 1951-2003, the model-estimated average air concentration was 0.2 microg/m3, the estimated surface soil concentration was 11 microg/kg, and the estimated drinking water concentration was 4 microg/L. Similar data were generated for 20 additional geographical areas around the facility. Comparison of measured PFOA concentrations in groundwater in the various water districts indicated that the models appeared to overpredict recent groundwater concentrations by a factor of 3 to 5. The predicted historical lifetime and average daily estimates of PFOA intake by persons who lived within 5 miles of the plant over the past 50 yr were about 10,000-fold less than the intake of the

  15. Retrospective beryllium exposure assessment at the Rocky Flats Environmental Technology site

    SciTech Connect

    Barnard, A.E.; Torma-Krajewski, J.; Viet, S.M.

    1997-05-01

    Since the 1960`s, beryllium machining was performed to make nuclear weapon components at the Department of Energy (DOE) Rocky Flats Plant. Beryllium exposure was assessed via fixed airhead (FAH) sampling in which the filter cassette was affixed to the machine, generally within a few feet of the worker`s breathing zone. Approximately 500,000 FAH samples were collected for beryllium over three decades. From 1984 to 1987, personal breathing zone (PBZ) samples were also collected as part of the evaluation of a new high velocity/low volume local exhaust ventilation (HV/LV LEV) system. The purpose of this study was to determine how the two types of sampling data could be used for an exposure assessment in the beryllium shop.

  16. Retrospective beryllium exposure assessment at the Rocky Flats Environmental Technology Site.

    PubMed

    Barnard, A E; Torma-Krajewski, J; Viet, S M

    1996-09-01

    The purpose of this study was to determine how two types of sampling data could be used for an exposure assessment in a beryllium shop at the Department of Energy's Rocky Flats Plant. Beryllium exposure was assessed via fixed airhead (FAH) sampling, in which the filter cassette was affixed to the machine, generally within a few feet of the worker's breathing zone. Approximately 500,000 FAH samples were collected for beryllium over three decades at the site. From 1984 to 1987, personal breathing zone (PBZ) samples also were collected as part of the evaluation of a new high velocity/lcw volume local exhaust ventilation system in the beryllium shop. FAH data indicated that four statistically different exposure periods existed from 1970 to 1988, as the FAH annual arithmetic means varied with changes in the local exhaust ventilation system and production levels. A matched comparison between the FAH and PBZ sample data found no direct linear correlation (R2 = 0.014); however, the mean PBZ results were higher than the mean FAH results (p = 0.0001). The mean PBZ level was 1.04 micrograms/m3 while the FAH average was 0.16 microgram/m3 (permissible exposure limit for beryllium: 2 micrograms/m3). A health surveillance program to identify cases of chronic beryllium disease (CBD) and beryllium sensitization has been implemented at Rocky Flats. To date, 53 cases of CBD and 86 cases of sensitivity to beryllium have been diagnosed. Continuing studies are evaluating semiquantitative dose response relationships for CBD using the exposure data discussed herein. PMID:8865588

  17. Retrospective cohort mortality study of workers at an aircraft maintenance facility. II. Exposures and their assessment.

    PubMed Central

    Stewart, P A; Lee, J S; Marano, D E; Spirtas, R; Forbes, C D; Blair, A

    1991-01-01

    Methods are presented that were used for assessing exposures in a cohort mortality study of 15,000 employees who held 150,000 jobs at an Air Force base from 1939 to 1982. Standardisation of the word order and spelling of the job titles identified 43,000 unique job title organisation combinations. Walkthrough surveys were conducted, long term employees were interviewed, and available industrial hygiene data were collected to evaluate historic exposures. Because of difficulties linking air monitoring data and use of specific chemicals to the departments identified in the work histories, position descriptions were used to identify the tasks in each job. From knowledge of the tasks and the chemicals used in those tasks the presence or absence of 23 chemicals or groups of chemicals were designated for each job organisation combination. Also, estimates of levels of exposure were made for trichloroethylene and for mixed solvents, a category comprising several solvents including trichloroethylene, Stoddard solvent, carbon tetrachloride, JP4 gasoline, freon, alcohols, 1,1,1-trichloroethane, acetone, toluene, methyl ethyl ketone, methylene chloride, o-dichlorobenzene, perchloroethylene, chloroform, styrene, and xylene. PMID:1878309

  18. The 'Maltreatment and Abuse Chronology of Exposure' (MACE) scale for the retrospective assessment of abuse and neglect during development.

    PubMed

    Teicher, Martin H; Parigger, Angelika

    2015-01-01

    There is increasing interest in childhood maltreatment as a potent stimulus that may alter trajectories of brain development, induce epigenetic modifications and enhance risk for medical and psychiatric disorders. Although a number of useful scales exist for retrospective assessment of abuse and neglect they have significant limitations. Moreover, they fail to provide detailed information on timing of exposure, which is critical for delineation of sensitive periods. The Maltreatment and Abuse Chronology of Exposure (MACE) scale was developed in a sample of 1051 participants using item response theory to gauge severity of exposure to ten types of maltreatment (emotional neglect, non-verbal emotional abuse, parental physical maltreatment, parental verbal abuse, peer emotional abuse, peer physical bullying, physical neglect, sexual abuse, witnessing interparental violence and witnessing violence to siblings) during each year of childhood. Items included in the subscales had acceptable psychometric properties based on infit and outfit mean square statistics, and each subscale passed Andersen's Likelihood ratio test. The MACE provides an overall severity score and multiplicity score (number of types of maltreatment experienced) with excellent test-retest reliability. Each type of maltreatment showed good reliability as did severity of exposure across each year of childhood. MACE Severity correlated 0.738 with Childhood Trauma Questionnaire (CTQ) score and MACE Multiplicity correlated 0.698 with the Adverse Childhood Experiences scale (ACE). However, MACE accounted for 2.00- and 2.07-fold more of the variance, on average, in psychiatric symptom ratings than CTQ or ACE, respectively, based on variance decomposition. Different types of maltreatment had distinct and often unique developmental patterns. The 52-item MACE, a simpler Maltreatment Abuse and Exposure Scale (MAES) that only assesses overall exposure and the original test instrument (MACE-X) with several additional

  19. Inter-rater agreement for a retrospective exposure assessment of asbestos, chromium, nickel and welding fumes in a study of lung cancer and ionizing radiation.

    PubMed

    Seel, E A; Zaebst, D D; Hein, M J; Liu, J; Nowlin, S J; Chen, P

    2007-10-01

    A retrospective exposure assessment of asbestos, welding fumes, chromium and nickel (in welding fumes) was conducted at the Portsmouth Naval Shipyard for a nested case-control study of lung cancer risk from external ionizing radiation. These four contaminants were included because of their potential to confound or modify the effect of a lung cancer-radiation relationship. The exposure assessment included three experienced industrial hygienists from the shipyard who independently assessed exposures for 3519 shop/job/time period combinations. A consensus process was used to resolve estimates with large differences. Final exposure estimates were linked to employment histories of the 4388 study subjects to calculate their cumulative exposures. Inter-rater agreement analyses were performed on the original estimates to better understand the estimation process. Although concordance was good to excellent (78-99%) for intensity estimates and excellent (96-99%) for frequency estimates, overall simple kappa statistics indicated only slight agreement beyond chance (kappa < 0.2). Unbalanced distributions of exposure estimates partly contributed to the weak observed overall inter-rater agreement. Pairwise weighted kappa statistics revealed better agreement between two of the three panelists (kappa = 0.19-0.65). The final consensus estimates were similar to the estimates made by these same two panelists. Overall welding fume exposures were fairly stable across time at the shipyard while asbestos exposures were higher in the early years and fell in the mid-1970s. Mean cumulative exposure for all study subjects was 520 fiber-days cc(-1) for asbestos and 1000 mg-days m(-3) for welding fumes. Mean exposure was much lower for nickel (140 microg-days m(-3)) and chromium (45 microg-days m(-3)). Asbestos and welding fume exposure estimates were positively associated with lung cancer in the nested case-control study. The radiation-lung cancer relationship was attenuated by the inclusion

  20. Cumulative Retrospective Exposure Assessment (REA) as a predictor of amphibole asbestos lung burden: validation procedures and results for industrial hygiene and pathology estimates

    PubMed Central

    Roggli, Victor L.; Boelter, Fred W.; Rasmuson, Eric J.; Redinger, Charles F.

    2014-01-01

    Context A detailed evaluation of the correlation and linearity of industrial hygiene retrospective exposure assessment (REA) for cumulative asbestos exposure with asbestos lung burden analysis (LBA) has not been previously performed, but both methods are utilized for case-control and cohort studies and other applications such as setting occupational exposure limits. Objective (a) To correlate REA with asbestos LBA for a large number of cases from varied industries and exposure scenarios; (b) to evaluate the linearity, precision, and applicability of both industrial hygiene exposure reconstruction and LBA; and (c) to demonstrate validation methods for REA. Methods A panel of four experienced industrial hygiene raters independently estimated the cumulative asbestos exposure for 363 cases with limited exposure details in which asbestos LBA had been independently determined. LBA for asbestos bodies was performed by a pathologist by both light microscopy and scanning electron microscopy (SEM) and free asbestos fibers by SEM. Precision, reliability, correlation and linearity were evaluated via intraclass correlation, regression analysis and analysis of covariance. Plaintiff’s answers to interrogatories, work history sheets, work summaries or plaintiff’s discovery depositions that were obtained in court cases involving asbestos were utilized by the pathologist to provide a summarized brief asbestos exposure and work history for each of the 363 cases. Results Linear relationships between REA and LBA were found when adjustment was made for asbestos fiber-type exposure differences. Significant correlation between REA and LBA was found with amphibole asbestos lung burden and mixed fiber-types, but not with chrysotile. The intraclass correlation coefficients (ICC) for the precision of the industrial hygiene rater cumulative asbestos exposure estimates and the precision of repeated laboratory analysis were found to be in the excellent range. The ICC estimates were performed

  1. Technology readiness assessments: A retrospective

    NASA Astrophysics Data System (ADS)

    Mankins, John C.

    2009-11-01

    The development of new system capabilities typically depends upon the prior success of advanced technology research and development efforts. These systems developments inevitably face the three major challenges of any project: performance, schedule and budget. Done well, advanced technology programs can substantially reduce the uncertainty in all three of these dimensions of project management. Done poorly, or not at all, and new system developments suffer from cost overruns, schedule delays and the steady erosion of initial performance objectives. It is often critical for senior management to be able to determine which of these two paths is more likely—and to respond accordingly. The challenge for system and technology managers is to be able to make clear, well-documented assessments of technology readiness and risks, and to do so at key points in the life cycle of the program. In the mid 1970s, the National Aeronautics and Space Administration (NASA) introduced the concept of "technology readiness levels" (TRLs) as a discipline-independent, programmatic figure of merit (FOM) to allow more effective assessment of, and communication regarding the maturity of new technologies. In 1995, the TRL scale was further strengthened by the articulation of the first definitions of each level, along with examples (J. Mankins, Technology readiness levels, A White Paper, NASA, Washington, DC, 1995. [1]). Since then, TRLs have been embraced by the U.S. Congress' General Accountability Office (GAO), adopted by the U.S. Department of Defense (DOD), and are being considered for use by numerous other organizations. Overall, the TRLs have proved to be highly effective in communicating the status of new technologies among sometimes diverse organizations. This paper will review the concept of "technology readiness assessments", and provide a retrospective on the history of "TRLs" during the past 30 years. The paper will conclude with observations concerning prospective future

  2. Retrospective dosimetry related to chronic environmental exposure

    NASA Technical Reports Server (NTRS)

    Degteva, M. O.; Kozheurov, V. P.; Tolstykh, E. I.; Neta, R. (Principal Investigator)

    1998-01-01

    Radioactive contamination of the environment occurred in the early fifties as a result of the releases from the Mayak plutonium production complex (Southern Urals, Russia). The releases of liquid wastes into the Techa river resulted in chronic exposure of 30,000 residents of the riverside communities. Since 1951 90Sr body burdens have been measured for over half of this cohort. This paper presents the analysis of data on 90Sr in humans and describes the reconstruction of internal doses for these people.

  3. Retrospective evaluation of occupational exposure to organic solvents: questionnaire and job exposure matrix.

    PubMed

    Stengel, B; Pisani, P; Limasset, J C; Bouyer, J; Berrino, F; Hémon, D

    1993-01-01

    Correct retrospective assignment of subjects to an exposure category is affected by a variety of problems: 1) lack of an objective lifetime measurement; 2) dependence upon the accuracy and thoroughness of the job description; 3) heavy reliance upon the knowledge of experts. The aim of the study was the quantification of the performance of a job exposure matrix (JEM) in evaluating solvent exposure, using expert judgements as the reference method. The sources of discrepancies between the two methods were analysed within the framework of two community-based case-control surveys. One included 765 cases of bladder cancer (BC) and 765 controls, the other 298 cases of glomerulonephritis (GN) and 298 controls. The JEM had been set up previously for a case-control study on laryngeal cancer and is based on 4000 discrete job titles. Comparison between the JEM and expert exposure evaluation was carried out for 2736 job periods in the BC study and 929 in the GN study. Categories of exposure for both experts and JEM were dichotomized, using different cutoff points for exposure and non-exposure. Prevalence of exposure as assessed by the experts was twice as high in the GN study (19%) as in the BC study (10%), showing the importance of the questionnaire design and of the inclusiveness of the definition of exposure. Sensitivity of the JEM vis-a-vis the experts was low (23-63%), whereas specificity was rather high (87-98%). The best concordance between the two methods was obtained with a specific dichotomy from the JEM and a narrow definition of exposure by the experts. Bias and loss of power resulting from JEM misclassifications were calculated with a theoretical population odds ratio of 3 and an exposure prevalence of 10%. If the experts' classification of the subjects according to exposure is assumed to be 100% correct, using the JEM led to a bias in estimating the odds ratio, ranging from 1.5 to 2.1, and to a loss of power equivalent to a reduction in the number of subjects by a

  4. Exposure assessment of trichloroethylene.

    PubMed

    Wu, C; Schaum, J

    2000-05-01

    This article reviews exposure information available for trichloroethylene (TCE) and assesses the magnitude of human exposure. The primary sources releasing TCE into the environment are metal cleaning and degreasing operations. Releases occur into all media but mostly into the air due to its volatility. It is also moderately soluble in water and can leach from soils into groundwater. TCE has commonly been found in ambient air, surface water, and groundwaters. The 1998 air levels in microg/m(3) across 115 monitors can be summarized as follows: range = 0.01-3.9, mean = 0.88. A California survey of large water utilities in 1984 found a median concentration of 3.0 microg/L. General population exposure to TCE occurs primarily by inhalation and water ingestion. Typical average daily intakes have been estimated as 11-33 microg/day for inhalation and 2-20 microg/day for ingestion. A small portion of the population is expected to have elevated exposures as a result of one or more of these pathways: inhalation exposures to workers involved in degreasing operations, ingestion and inhalation exposures occurring in homes with private wells located near disposal/contamination sites, and inhalation exposures to consumers using TCE products in areas of poor ventilation. More current and more extensive data on TCE levels in indoor air, water, and soil are needed to better characterize the distribution of background exposures in the general population and elevated exposures in special subpopulations.

  5. Exposure assessment of trichloroethylene.

    PubMed Central

    Wu, C; Schaum, J

    2000-01-01

    This article reviews exposure information available for trichloroethylene (TCE) and assesses the magnitude of human exposure. The primary sources releasing TCE into the environment are metal cleaning and degreasing operations. Releases occur into all media but mostly into the air due to its volatility. It is also moderately soluble in water and can leach from soils into groundwater. TCE has commonly been found in ambient air, surface water, and groundwaters. The 1998 air levels in microg/m(3) across 115 monitors can be summarized as follows: range = 0.01-3.9, mean = 0.88. A California survey of large water utilities in 1984 found a median concentration of 3.0 microg/L. General population exposure to TCE occurs primarily by inhalation and water ingestion. Typical average daily intakes have been estimated as 11-33 microg/day for inhalation and 2-20 microg/day for ingestion. A small portion of the population is expected to have elevated exposures as a result of one or more of these pathways: inhalation exposures to workers involved in degreasing operations, ingestion and inhalation exposures occurring in homes with private wells located near disposal/contamination sites, and inhalation exposures to consumers using TCE products in areas of poor ventilation. More current and more extensive data on TCE levels in indoor air, water, and soil are needed to better characterize the distribution of background exposures in the general population and elevated exposures in special subpopulations. Images Figure 1 PMID:10807565

  6. 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.

  7. 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...

  8. Retrospective exposure data for baby and children care products: an analysis of 48 clinical studies.

    PubMed

    Gomez-Berrada, Marie-Pierre; Gautier, Florian; Parent-Massin, Dominique; Ferret, Pierre-Jacques

    2013-07-01

    To conduct a reliable safety assessment, accurate exposure information for cosmetic products and ingredients is needed. The aim of the present retrospective study was to determine the amount per application and the daily exposure for some of the most commonly used baby cosmetic products. Consumption data from 48 clinical studies performed on 1481 babies and children (from 0 to 10 years old) were reviewed and used to conduct a probabilistic evaluation of dermal exposure. Six categories of products were reviewed: rinseoff products for hair and body; rinse-off products for the whole body; leave-on products for face and body; cleansers for face and body; diaper dermatitis treatment products; shampoos. Subjects were provided with products and recorded detailed daily usage information over a 1-4-week period, depending on the study. Products were weighed at the start and upon completion of each study in order to determine the total amount of product used. The mean, median, standard deviation and 95th percentile were calculated for daily consumption and exposure, for several age groups from 0 to 10 years old. This study provides current baby cosmetic exposure information for commonly used products which will be useful for risk assessment purposes. PMID:23562927

  9. 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...

  10. Rifampicin in tuberculous meningitis: a retrospective assessment.

    PubMed

    Latorre, P; Gallofré, M; Laporte, J R; Massons, J

    1984-01-01

    To shed some light on the potential value of rifampicin in the treatment of tuberculous meningitis (TBM) in adults, a retrospective analysis has been made of 143 medical records from 4 hospitals for the period 1967-80. Treatment of TBM with rifampicin and other antituberculous drugs in combination (Group B) was compared to other regimes which did not include rifampicin (Group A). There were 64 patients in Group B and 79 in Group A. The two groups of patients did not differ significantly in their prognostic characteristics. The total mortality was 14.7%: it was higher among patients not treated with rifampicin (24%; Group A) than amongst those given rifampicin (3.1%; Group B; chi 2 = 10.74; p less than 0.005). The difference was also statistically significant (chi 2 = 6.88; p less than 0.01) if patients who died during the first 48 h after the institution of treatment were excluded. No significant difference in mortality rate was found when patients treated with rifampicin plus isoniazid (INH) 8-10 mg/kg (1 death out of 41 patients) were compared to patients treated with INH 15 mg/kg (2 deaths out of 20 patients). Neurological sequelae recorded during a 6 month follow-up period were more severe among patients not treated with rifampicin.

  11. Assessing Pragmatics: DCTS and Retrospective Verbal Reports

    ERIC Educational Resources Information Center

    Beltrán-Palanques, Vicente

    2016-01-01

    Assessing pragmatic knowledge in the instructed setting is seen as a complex but necessary task, which requires the design of appropriate research methodologies to examine pragmatic performance. This study discusses the use of two different research methodologies, namely those of Discourse Completion Tests/Tasks (DCTs) and verbal reports. Research…

  12. Retrospective evaluation of exposure index (EI) values from plain radiographs reveals important considerations for quality improvement

    SciTech Connect

    Mothiram, Ursula; Brennan, Patrick C; Robinson, John; Lewis, Sarah J; Moran, Bernadette

    2013-12-15

    Following X-ray exposure, radiographers receive immediate feedback on detector exposure in the form of the exposure index (EI). To identify whether radiographers are meeting manufacturer-recommended EI (MREI) ranges for routine chest, abdomen and pelvis X-ray examinations under a variety of conditions and to examine factors affecting the EI. Data on 5000 adult X-ray examinations including the following variables were collected: examination parameters, EI values, patient gender, date of birth, date and time of examination, grid usage and the presence of implant or prosthesis. Descriptive statistics were used to summarize each data set and the Mann–Whitney U test was used to determine significant differences, with P < 0.05 indicating significance for all tests. Most examinations demonstrated EI values that were outside the MREI ranges, with significantly higher median EI values recorded for female patient radiographs than those for male patients for all manufacturers, indicating higher detector exposures for all units except for Philips digital radiography (DR), where increased EI values indicate lower exposure (P = 0.01). Median EI values for out of hours radiography were also significantly higher compared with normal working hours for all technologies (P ≤ 0.02). Significantly higher median EI values were demonstrated for Philips DR chest X-rays without as compared to those with the employment of a grid (P = 0.03), while significantly lower median EI values were recorded for Carestream Health computed radiography (CR) chest X-rays when an implant or prosthesis was present (P = 0.02). Non-adherence to MREIs has been demonstrated with EI value discrepancies being dependent on patient gender, time/day of exposure, grid usage and the presence of an implant or prosthesis. Retrospective evaluation of EI databases is a valuable tool to assess the need of quality improvement in routine DR.

  13. Potential for bias in epidemiologic studies that rely on glass-based retrospective assessment of radon

    SciTech Connect

    Weinberg, C.R.

    1995-11-01

    Retrospective assessment of exposure to radon remains the greatest challenge in epidemiologic efforts to assess lung cancer risk associated with residential exposure. An innovative technique based on measurement of {alpha}-emitting, long-lived daughters embedded by recoil into household glass may one day provide improved radon dosimetry. Particulate air pollution is known, however, to retard the plate-out of radon daughters. This would be expected to result in a differential effect on dosimetry, where the calibration curve relating the actual historical radon exposure to the remaining {alpha}-activity in the glass would be different in historically smoky and nonsmoky environments. The resulting {open_quotes}measurement confounding{close_quotes} can distort inferences about the effect of radon and can also produce spurious evidence for synergism between radon exposure and cigarette smoking. 18 refs., 4 figs.

  14. Potential for bias in epidemiologic studies that rely on glass-based retrospective assessment of radon.

    PubMed Central

    Weinberg, C R

    1995-01-01

    Retrospective assessment of exposure to radon remains the greatest challenge in epidemiologic efforts to assess lung cancer risk associated with residential exposure. An innovative technique based on measurement of alpha-emitting, long-lived daughters embedded by recoil into household glass may one day provide improved radon dosimetry. Particulate air pollution is known, however, to retard the plate-out of radon daughters. This would be expected to result in a differential effect on dosimetry, where the calibration curve relating the actual historical radon exposure to the remaining alpha-activity in the glass would be different in historically smoky and nonsmoky environments. The resulting "measurement confounding" can distort inferences about the effect of radon and can also produce spurious evidence for synergism between radon exposure and cigarette smoking. Images Figure 1. Figure 2. Figure 3. Figure 4. PMID:8605854

  15. Assessing secondhand smoke exposure with reported measures

    PubMed Central

    Elf, Jessica L; Cummings, K Michael; Fong, Geoffrey T; Hovell, Melbourne F; Klein, Jonathan D; McMillen, Robert; Winickoff, Jonathan P; Samet, Jonathan M

    2013-01-01

    Non-smokers are exposed to tobacco smoke from the burning cigarette and the exhaled smoke from smokers. In spite of decades of development of approaches to assess secondhand smoke exposure (SHSe), there are still unresolved methodological issues. This manuscript summarises the scientific evidence on the use of SHSe reported measures and their methods, objectives, strengths and limitations; and discusses best practices for assessing behaviour leading to SHSe for lifetime and immediate or current SHSe. Recommendations for advancing measurement science of SHSe are provided. Behavioural measures of SHSe commonly rely on self-reports from children and adults. Most commonly, the methodology includes self, proxy and interview-based reporting styles using retrospective recall or diary-style reporting formats. The reporting method used will vary based upon the subject of interest, assessment objectives and cultural context. Appropriately implemented, reported measures of SHSe provide an accurate, timely and cost-effective method for assessing exposure time, location and quantity in a wide variety of populations. PMID:22949496

  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. 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.

  18. 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...

  19. Test-retest reliability of retrospective self-reported maternal exposure to childhood abuse and neglect.

    PubMed

    Cammack, Alison L; Hogue, Carol J; Drews-Botsch, Carolyn D; Kramer, Michael R; Pearce, Bradley D; Knight, Bettina T; Stowe, Zachary N; Newport, D Jeffrey

    2016-04-01

    Retrospective reports of exposure to childhood trauma indicate it is common. There is growing interest in relationships between maternal exposure to childhood adversity, perinatal mental health, and pregnancy outcomes. The goal of this study was to describe the self-reported prevalence and test-retest reliability of exposure to childhood maltreatment using the Childhood Trauma Questionnaire among adult women around the time of pregnancy. A substantial proportion of women reported exposure to maltreatment and reliability was generally at least moderate, indicating consistent reporting.

  20. Biomarker-Based Calibration of Retrospective Exposure Predictions of Perfluorooctanoic Acid

    PubMed Central

    2015-01-01

    Estimated historical exposures and serum concentrations of perfluorooctanoic acid (PFOA) have been extensively used in epidemiologic studies that examined associations between PFOA exposures and adverse health outcomes among residents in highly exposed areas in the Mid-Ohio Valley. Using measured serum PFOA levels in 2005–2006, we applied two calibration methods to these retrospective exposure predictions: (1) multiplicative calibration and (2) Bayesian pharmacokinetic calibration with larger adjustments to more recent exposure estimates and smaller adjustments to exposure estimates for years farther in the past. We conducted simulation studies of various hypothetical exposure scenarios and compared hypothetical true historical intake rates with estimates based on mis-specified baseline exposure and pharmacokinetic models to find the method with the least bias. The Bayesian method outperformed the multiplicative method if a change to bottled water consumption was not reported or if the half-life of PFOA was mis-specified. On the other hand, the multiplicative method outperformed the Bayesian method if actual tap water consumption rates were systematically overestimated. If tap water consumption rates gradually decreased over time because of substitution with bottled water or other liquids, neither method clearly outperformed another. Calibration of retrospective exposure estimates using recently collected biomarkers may help reduce uncertainties in environmental epidemiologic studies. PMID:24730513

  1. 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...

  2. Developing Korean Standard for Nanomaterial Exposure Assessment

    PubMed Central

    Lee, Ji Hyun; Lee, Jun Yeob

    2011-01-01

    Nanotechnology is now applied to many industries, resulting in wide range of nanomaterial-containing products, such as electronic components, cosmetic, medicines, vehicles, and home appliances. Nanoparticles can be released throughout the life cycle of nanoproducts, including the manufacture, consumer use, and disposal, thereby involving workers, consumers, and the environment in potential exposure. However, there is no current consensus on the best sampling method for characterizing manufactured-nanoparticle exposure. Therefore, this report aims to provide a standard method for assessing nanoparticle exposure, including the identification of nanoparticle emission, the assessment of worker exposure, and the evaluation of exposure mitigation actions in nanomaterial-handling workplaces or research institutes. PMID:24278552

  3. Non-Occupational Post-Exposure Prophylaxis for HIV: 10-Year Retrospective Analysis in Seattle, Washington

    PubMed Central

    McDougal, Sarah J.; Alexander, Jeremiah; Dhanireddy, Shireesha; Harrington, Robert D.; Stekler, Joanne D.

    2014-01-01

    Despite treatment guidelines in place since 2005, non-occupational post-exposure HIV prophylaxis (nPEP) remains an underutilized prevention strategy. We conducted a retrospective chart review of patients presenting to a publicly-funded HIV clinic in Seattle, Washington for nPEP between 2000 and 2010 (N = 360). nPEP prescriptions were provided for 324 (90%) patients; 83% of prescription decisions were appropriate according to Centers for Disease Control and Prevention guidelines, but only 31% (N = 111/360) of patients were considered “high risk.” In order to use limited resources most efficiently, public health agencies should target messaging for this high-cost intervention to individuals with high-risk HIV exposures. PMID:25140868

  4. 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.

  5. Occupational Exposure to Human Immunodeficiency Virus in Health Care Providers: A Retrospective Analysis

    PubMed Central

    Aggarwal, Varun; Seth, Anju; Chandra, Jagdish; Gupta, Rohini; Kumar, Praveen; Dutta, Ashok Kumar

    2012-01-01

    Objectives: To determine the population at risk, risk factors, and outcome of occupational exposure to blood and body fluids in health care providers. Materials and Methods: Retrospective review of two and half year data of ongoing surveillance of occupational exposure to blood and body fluids in a tertiary care hospital. Results: 103 Health Care Providers (HCP) reported an occupational exposure to blood and body fluids during the period under review. These comprised 72 (69.9%) doctors, 20 (19.4%) nursing personnel, and 11 (10.6%) cleaning staff. Of the doctors, 65% were interns. 53.4% HCP had work experience of less than one year. Circumstances of exposure included clinical procedures (48%), sweeping/handling used sharps (29%), recapping (16%), and surgery (6.9%). 74.3% of the exposures were due to non-compliance with universal precautions and were thus preventable. The device most frequently implicated in causing injury was hollow bore needle (n=85, 82.5%). Human Immunodeficiency Virus (HIV) status of the source was positive in 6.8% cases, negative in 53.4% cases, and unknown in remaining 39.8% cases. Postexposure prophylaxis (PEP) was indicated in 100 (97.08%) cases and was initiated within 2 h of exposure in 26.8% HCP. In 23.2% HCP, PEP initiation was delayed beyond 72 h of exposure due to late reporting. Thirteen HCP received expanded and the remaining received basic regime. Of the 82 HCP followed up, 15 completed the full course, while 55 stopped PEP after the first dose due to negative source status. Twelve HCP with exposure to blood of unknown HIV status discontinued PEP despite counseling. Complete follow-up for seroconversion was very poor among the HCP. HIV status at 6 month of exposure is not known for any HCP. Conclusions: Failure to follow universal precautions including improper disposal of waste was responsible for majority of occupational exposures. HCP need to be sensitized regarding hospital waste management, management of occupational exposure

  6. Arsenic Exposure and Outcomes of Antimonial Treatment in Visceral Leishmaniasis Patients in Bihar, India: A Retrospective Cohort Study

    PubMed Central

    Perry, Meghan R.; Prajapati, Vijay K.; Menten, Joris; Raab, Andrea; Feldmann, Joerg; Chakraborti, Dipankar; Sundar, Shyam; Fairlamb, Alan H.; Boelaert, Marleen; Picado, Albert

    2015-01-01

    Background In the late twentieth century, emergence of high rates of treatment failure with antimonial compounds (SSG) for visceral leishmaniasis (VL) caused a public health crisis in Bihar, India. We hypothesize that exposure to arsenic through drinking contaminated groundwater may be associated with SSG treatment failure due to the development of antimony-resistant parasites. Methods A retrospective cohort design was employed, as antimony treatment is no longer in routine use. The study was performed on patients treated with SSG between 2006 and 2010. Outcomes of treatment were assessed through a field questionnaire and treatment failure used as a proxy for parasite resistance. Arsenic exposure was quantified through analysis of 5 water samples from within and surrounding the patient’s home. A logistic regression model was used to evaluate the association between arsenic exposure and treatment failure. In a secondary analysis survival curves and Cox regression models were applied to assess the risk of mortality in VL patients exposed to arsenic. Results One hundred and ten VL patients treated with SSG were analysed. The failure rate with SSG was 59%. Patients with high mean local arsenic level had a non-statistically significant higher risk of treatment failure (OR = 1.78, 95% CI: 0.7–4.6, p = 0.23) than patients using wells with arsenic concentration <10 μg/L. Twenty one patients died in our cohort, 16 directly as a result of VL. Arsenic levels ≥ 10 μg/L increased the risk of all-cause (HR 3.27; 95% CI: 1.4–8.1) and VL related (HR 2.65; 95% CI: 0.96–7.65) deaths. This was time dependent: 3 months post VL symptom development, elevated risks of all-cause mortality (HR 8.56; 95% CI: 2.5–29.1) and of VL related mortality (HR 9.27; 95% CI: 1.8–49.0) were detected. Discussion/Conclusion This study indicates a trend towards increased treatment failure in arsenic exposed patients. The limitations of the retrospective study design may have masked a strong

  7. Residential exposure to aircraft noise and hospital admissions for cardiovascular diseases: multi-airport retrospective study

    PubMed Central

    Correia, Andrew W; Peters, Junenette L; Levy, Jonathan I; Melly, Steven

    2013-01-01

    Objective To investigate whether exposure to aircraft noise increases the risk of hospitalization for cardiovascular diseases in older people (≥65 years) residing near airports. Design Multi-airport retrospective study of approximately 6 million older people residing near airports in the United States. We superimposed contours of aircraft noise levels (in decibels, dB) for 89 airports for 2009 provided by the US Federal Aviation Administration on census block resolution population data to construct two exposure metrics applicable to zip code resolution health insurance data: population weighted noise within each zip code, and 90th centile of noise among populated census blocks within each zip code. Setting 2218 zip codes surrounding 89 airports in the contiguous states. Participants 6 027 363 people eligible to participate in the national medical insurance (Medicare) program (aged ≥65 years) residing near airports in 2009. Main outcome measures Percentage increase in the hospitalization admission rate for cardiovascular disease associated with a 10 dB increase in aircraft noise, for each airport and on average across airports adjusted by individual level characteristics (age, sex, race), zip code level socioeconomic status and demographics, zip code level air pollution (fine particulate matter and ozone), and roadway density. Results Averaged across all airports and using the 90th centile noise exposure metric, a zip code with 10 dB higher noise exposure had a 3.5% higher (95% confidence interval 0.2% to 7.0%) cardiovascular hospital admission rate, after controlling for covariates. Conclusions Despite limitations related to potential misclassification of exposure, we found a statistically significant association between exposure to aircraft noise and risk of hospitalization for cardiovascular diseases among older people living near airports. PMID:24103538

  8. Retrospective cohort study of lung cancer and diesel exhaust exposure in railroad workers

    SciTech Connect

    Garshick, E.; Schenker, M.B.; Munoz, A.; Segal, M.; Smith, T.J.; Woskie, S.R.; Hammond, S.K.; Speizer, F.E.

    1988-04-01

    The risk of lung cancer as a result of exposure to diesel exhaust from railroad locomotives was assessed in a cohort of 55,407 white male railroad workers 40 to 64 yr of age in 1959 who had started railroad service 10 to 20 years earlier. The cohort was traced until the end of 1980, and death certificates were obtained for 88% of 19,396 deaths; 1694 lung cancer cases were identified. Yearly railroad job from 1959 to death or retirement was available from the Railroad Retirement Board, and served as an index of diesel exhaust exposure. Directly standardized rates and a proportional hazards model were used to calculate the relative risk of lung cancer based on work in a job with diesel exhaust exposure beginning in 1959. A relative risk of 1.45 (95% CI = 1.11, 1.89) for lung cancer was obtained in the group of workers 40 to 44 yr of age in 1959, the group with the longest possible duration of diesel exposure. The cohort was selected to minimize the effect of past railroad asbestos exposure, and analysis with workers with possible asbestos exposure excluded resulted in a similarly elevated risk. Workers with 20 yr or more elapsed since 1959, the effective start of diesel exposure for the cohort, had the highest relative risk. These results taken in conjunction with other reported results support the hypothesis that occupational exposure to diesel exhaust results in a small but significantly elevated risk for lung cancer.

  9. Chronic Arsenic Exposure and Risk of Post Kala-azar Dermal Leishmaniasis Development in India: A Retrospective Cohort Study

    PubMed Central

    Das, Sushmita; Mandal, Rakesh; Rabidas, Vidya Nand; Verma, Neena; Pandey, Krishna; Ghosh, Ashok Kumar; Kesari, Sreekant; Kumar, Ashish; Purkait, Bidyut; Lal, Chandra Sekhar; Das, Pradeep

    2016-01-01

    Background Visceral leishmaniasis (VL), with the squeal of Post-kala-azar dermal leishmaniasis (PKDL), is a global threat for health. Studies have shown sodium stibogluconate (SSG) resistance in VL patients with chronic arsenic exposure. Here, we assessed the association between arsenic exposure and risk of developing PKDL in treated VL patients. Methods In this retrospective study, PKDL patients (n = 139), earlier treated with SSG or any other drug during VL, were selected from the study cohort. Trained physicians, unaware of arsenic exposure, interviewed them and collected relevant data in a questionnaire format. All probable water sources were identified around the patient’s house and water was collected for evaluation of arsenic concentration. A GIS-based village-level digital database of PKDL cases and arsenic concentration in groundwater was developed and individual point location of PKDL cases were overlaid on an integrated GIS map. We used multivariate logistic regression analysis to assess odds ratios (ORs) for association between arsenic exposure and PKDL development. Results Out of the 429 water samples tested, 403 had arsenic content of over 10 μg/L, with highest level of 432 μg/L among the seven study villages. Multivariate adjusted ORs for risk of PKDL development in comparison of arsenic concentrations of 10.1–200 μg/L and 200.1–432.0 μg/L were 1.85 (1.13–3.03) and 2.31 (1.39–3.8) respectively. Interestingly, similar results were found for daily dose of arsenic and total arsenic concentration in urine sample of the individual. The multivariate-adjusted OR for comparison of high baseline arsenic exposure to low baseline arsenic exposure of the individuals in the study cohort was 1.66 (95% CI 1.02–2.7; p = 0.04). Conclusion Our findings indicate the need to consider environmental factors, like long time arsenic exposure, as an additional influence on treated VL patients towards risk of PKDL development in Bihar. PMID:27776123

  10. Hospital nurses' occupational exposure to blood: prospective, retrospective, and institutional reports.

    PubMed Central

    Aiken, L H; Sloane, D M; Klocinski, J L

    1997-01-01

    OBJECTIVES: This study examined nurses risk of exposure to blood resulting from injuries with needles and sharps, the methods of estimating those risks, and the factors affecting risks. METHODS: Nurses on 40 medical units in 20 hospitals in cities with a high incidence of AIDS were studied. Percutaneous injuries were documented for every shift during a 30-day period. These prospective reports were compared with retrospective and institutional reports. Factors affecting the likelihood of injuries were explored. RESULTS: Based on the prospective reports, the rate of injuries to staff nurses was 0.8 per nurse-year. Prospective and retrospective rates were similar, while institutional rates were significantly lower. Factors associated with increased injuries included recapping needles and temporary work assignments. Working in hospitals characterized by professional nurse practice models and taking precautions to avoid blood contact were associated with fewer injuries. CONCLUSIONS: Injuries from needlesticks are more common than institutional reports suggest and do not occur at random. Diminishing the frequency with which nurses recap needles, increasing precautions they take, reducing use of temporary nursing personnel, and implementing organizational changes may lower the odds of nurses being injured. PMID:9065213

  11. A Retrospective Self-Assessment of the SURFO Summer Internship Program in Oceanography

    NASA Astrophysics Data System (ADS)

    Pockalny, R. A.; Donohue, K. A.; Fliegler, J.

    2009-12-01

    The Summer Undergraduate Research Fellowships in Oceanography (SURFO) program at the Graduate School of Oceanography/University of Rhode Island is an NSF-funded Research Experience for Undergraduates site program with a programmatic research niche focused on quantitative aspects of Oceanography. Each summer-cohort includes 9-12 participants (rising seniors) who are paired with a primary research advisor and often with a graduate student mentor. The primary components of the 10-week program include a 4-week introductory phase and a 6-week core research phase. A retrospective self-assessment instrument gauged the confidence, attitude and comfort level of participants with; 1) core math and science subjects, 2) oceanography-related subjects, 3) research skills, and 4) SURFO and GSO staff. SURFO participants evaluated themselves at the start of the program, after the introductory phase, and at the end of the program. Participants were also asked to reassess their initial evaluations and provide an updated score. The pre-assessment results indicate that the program recruits students from the target group (e.g., strong physics and math backgrounds, but with limited exposure to oceanography). The results also indicate that the students are initially comfortable with their advising team, but not so comfortable with their research topic and research skills. The post-introductory phase results indicate large increases in comfort level with the advising team and the local research community yet little or no change is indicated for research skills. The final assessments show large changes in oceanography-content knowledge, research topic, and research skills. The retrospective reassessment indicates an initial overconfidence in most categories. Overall, the largest changes occurred during the core research portion of the program. These results reinforce the importance/effectiveness of authentic, hands-on, inquiry-based research for higher learning and training the next

  12. Proposal to the National Science Foundation for a retrospective technology assessment of submarine telegraphy

    NASA Technical Reports Server (NTRS)

    Coates, V. T.; Finn, B. S.

    1975-01-01

    The conceptual and methodological importance of doing retrospective technology assessments is summarized. The rationale for the study of submarine telegraphy is briefly summarized along with the study plan, the management plan, and dissemination and utilization of the results.

  13. Exposure assessment for chemical and physical agents.

    PubMed

    Moretto, Angelo

    2015-01-01

    Exposure assessment to either chemical or physical agents, as applicable, is a necessary step for both etiologic diagnosis of occupational disease and health surveillance of workers. The assessment can be carried out by measurements of concentrations in air of the substance by either fixed or personal samplers. The former give an indication of the general environment, the latter, applied near the mouth of the worker, provide personalized information. Dermal exposure (deposition) and absorption occur in the occupational setting, but their measurement is so complex that there are no routine methods and no exposure limits established. Oral exposure is accidental or associated with poor hygienic practices, is very difficult to assess, and there are no occupational exposure limits of oral intake. Also accidental injuries caused by needles or other sharp objects that might be contaminated by chemicals occur but exposure assessment in this condition is almost impossible. Exposure is also assessed by biologic monitoring that entails measurements of the substance and/or of its metabolite(s) in accessible fluids, generally urine, blood, or expired air. Biochemical changes, e.g., enzyme inhibition, associated with exposure are also measured. The results of these measurements are compared with existing limit values in order to conclude on the safety of the working conditions. Since the limit values are derived with the application of conservative assumptions, there are no fine lines between health and disease. Therefore, in the clinical setting values below the limit can be generally regarded as safe. Values above the limits should be considered in conjunction with all other information to judge on the likelihood that the disease under investigation may have been caused by exposure to the substance. PMID:26563782

  14. Models for retrospective quantification of indoor radon exposure in case-control studies

    SciTech Connect

    Gerken, M.; Kreienbrock, L.; Wellmann, J.; Kreuzer, M.; Wichmann, H.E.

    2000-03-01

    In epidemiologic studies on lung cancer risk due to indoor radon the quantification of individual radon exposure over a long time period is one of the main issues. Therefore, radon measurements in one or more dwellings, which in total have been inhabited by the participants for a sufficient time-period, are necessary as well as consideration of changes of building characteristics and ventilation habits, which influence radon concentration. Given data on 1-y alpha-track measurements and personal information from 6,000 participants of case-control studies in West and East Germany, and improved method is developed to assess individual radon exposure histories. Times spent in different rooms of the dwelling, which are known from a personal questionnaire, are taken into account. The time spent outside the house varies substantially among the participants. Therefore, assuming a substantially lower radon exposure outside the dwelling, the residence time constitutes an important aspect of total radon exposure. By means of an analysis of variance, important determinants of indoor radon are identified, namely constant conditions such as type of house, type of construction, year of construction, floor and type of basement, and changeable conditions such as heating system, window insulation, and airing habits. A correction of measurements in former dwellings by factors derived from the analysis is applied if current living conditions differ from those of the participants at the time when they were living in the particular dwellings. In rare cases the adjustment for changes leads to a correction of the measurements with a factor of about 1.4, but a reduction of 5% on average only. Exposure assessment can be improved by considering time at home and changes of building and ventilation conditions that affect radon concentration. The major concern that changes in ventilation habits and building conditions lead to substantial errors in exposure assessment cannot be confirmed in the

  15. Exposure scenario libraries as a tool for exposure assessment

    NASA Astrophysics Data System (ADS)

    Sánchez Jiménez, Araceli; Rashid, Shahzad; Brouwer, Derk; Fransman, Wouter; Fito, Carlos; Boulougouris, George; van Tongeren, Martie

    2015-05-01

    The development of nanotechnology has reached a point where it is being widely applied, and numerous nanomaterials and nano-enabled products are handled across a broad range of industrial sectors. Exposure extends beyond occupational settings as products containing nanomaterials are used by different consumer groups. Despite the knowledge on their toxic effects is growing there is still not OEL for most NMS and therefore the precautionary approach is still used where levels are kept as low as possible Therefore there is a need to assess workers and consumers exposure.

  16. Realistic retrospective dose assessments to members of the public around Spanish nuclear facilities.

    PubMed

    Jiménez, M A; Martín-Valdepeñas, J M; García-Talavera, M; Martín-Matarranz, J L; Salas, M R; Serrano, J I; Ramos, L M

    2011-11-01

    In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5×10(-5)mSv/y, in contrast to 1.6mSv/y from natural radiation or 1.3mSv/y from medical exposures.

  17. Pregnancy outcomes after exposure to tocilizumab: A retrospective analysis of 61 patients in Japan

    PubMed Central

    Nakajima, Ken; Watanabe, Omi; Mochizuki, Mayumi; Nakasone, Ayako; Ishizuka, Nobuhiko; Murashima, Atsuko

    2016-01-01

    Abstract Objectives: To assess the effects of tocilizumab on pregnancy outcomes in Japanese patients with rheumatic disease. Methods: Data from Chugai’s tocilizumab safety database (April 2005 to October 2014) were retrospectively analyzed to identify pregnancy outcomes in patients exposed to tocilizumab. Results: Data were available for 61 pregnancies exposed to tocilizumab, and outcomes were reported for 50 of those pregnancies. In 36 births, no congenital anomalies were identified; however, six neonatal abnormalities were reported: five cases of low birth weight (<2500 g) and one case of neonatal asphyxia. Of 36 births, tocilizumab was resumed during lactation in two patients, with no subsequent adverse events reported in newborns. The spontaneous abortion rate was 18.0% (9 of 50 pregnancies), which is comparable to the rate in the general population. The five terminated pregnancies included one case of caudal regression syndrome. Conclusions: The present retrospective study of 61 pregnancies exposed to tocilizumab at conception indicated no increased rates of spontaneous abortion or congenital abnormalities in patients with rheumatic disease. However, further study is necessary to confirm the benefit-risk profile of tocilizumab treatment during pregnancy. PMID:26873562

  18. Assessing exposures to environmental tobacco smoke

    SciTech Connect

    Leaderer, B.P. )

    1990-01-01

    The combustion of tobacco indoors results in the emission of a wide range of air contaminants that are associated with a variety of acute and chronic health and comfort effects. Exposures to environmental tobacco smoke (ETS) are assessed for epidemiologic studies and risk assessment and risk management applications. An individual's or population's exposure to ETS can be assessed by direct methods, which employ personal air monitoring and biomarkers, and indirect methods, which utilize various degrees of microenvironmental measurements of spaces, models, and questionnaires in combination with time-activity information. The major issues related to assessing exposures to ETS are summarized and discussed, including the physical-chemical nature of ETS air contaminants, use of proxy air contaminants to represent ETS, use of biomarkers, models for estimating ETS concentrations indoors, and the application of questionnaires.

  19. Assessing radiation exposure during endoscopic-guided percutaneous nephrolithotomy

    PubMed Central

    Lantz, Andrea G.; O’Malley, Padraic; Ordon, Michael; Lee, Jason Y.

    2014-01-01

    Introduction: Percutaneous nephrolithotomy (PCNL) may be associated with significant ionizing radiation exposure for patients and operating room staff. Endoscopic-guided PCNL (ePCNL) is a technique that may be associated with less radiation exposure. This study examines ePCNL-related radiation exposure (fluoroscopy time, effective dose) and investigates variables that may predict increased exposure. Methods: A retrospective review of all consecutive ePCNLs performed at our institution, by a single surgeon, was conducted between November 2011 and November 2013. Patient demographics, stone characteristics and perioperative details were recorded, including radiation exposure. Pearson and Spearman correlation were used to assess variables correlated with radiation exposure. Results: In total, 55 ePCNL cases were included in the study. The mean age was 60 ± 15 years, mean body mass index (BMI) 30.0 ± 6.4 kg/m2 and mean stone size 3.2 × 2.1 cm. Seven cases (13%) involved complete staghorn stones, and 69% involved supracostal punctures. The mean fluoroscopy time was 3.4 ± 2.3 minutes, mean ED 2.4 ± 1.9 mSv. The treatment success rate, assessed 1-week postoperatively, was 87.3% and 7.3% of cases required ancillary procedures. The overall complication rate was 29%, but only 3 cases (5.5%) were Clavien ≥3. Longer fluoroscopy time correlated with increased stone size (p < 0.01), longer operative time (p < 0.01) and lower treatment success rates (p < 0.01); higher effective dose correlated with longer fluoroscopy time (p < 0.01) and increased skin-to-stone distance (p < 0.01). BMI did not correlate with fluoroscopy time or effective dose. Conclusions: Outcomes of ePCNL are comparable to traditional PCNL techniques and may be associated with lower radiation exposure, particularly beneficial for patients with higher BMI. PMID:25408802

  20. 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

  1. Health assessment of exposure to developmental toxicants

    SciTech Connect

    Kimmel, C.A.

    1987-07-01

    In 1984, the U.S. EPA published proposed Guidelines for the Health Assessment of Suspect Developmental Toxicants. The assessment of data from studies on developmental effects of chemical exposure and the estimation of risk for humans is a difficult process. Although structure/activity relationships and data from short-term tests are often used in the risk-assessment process for assessing carcinogens, these are not useful as the first step in developmental toxicity risk assessment. Human epidemiological data are used, if available, but often the only available evidence is from animal studies. Therefore, the guidelines focus on the evaluation of data from routine animal testing studies.

  2. Assessing exposures to inhaled complex mixtures.

    PubMed Central

    Leaderer, B P; Lioy, P J; Spengler, J D

    1993-01-01

    In the course of daily activities, individuals spend varying amounts of time in different spaces where they are exposed to a complex mixture of gas, vapor, and particulate contaminants. The term complex is used in this paper to refer to binary mixtures as well as truly complex mixtures of three or more constituents. The diversity of the environments where pollution may occur, the number of pollutants that may be present, and the nature of the activity in the environment combine to pose a challenge to investigators of the health effects of air pollutants. This article discusses several methods of measuring or assessing exposure to complex mixture air contaminants that include time-activity assessments, personal monitoring, biomarkers of exposure, and microenvironmental models that can be employed singly or in combination in a protocol for exposure assessment. The use of nested designs, involving more intensive data collection from samples or subjects, is also considered. PMID:8206025

  3. Health hazards of fire fighters: exposure assessment.

    PubMed Central

    Brandt-Rauf, P W; Fallon, L F; Tarantini, T; Idema, C; Andrews, L

    1988-01-01

    There is growing concern over the detrimental health effects to firefighters produced by exposure to combustion byproducts of burning materials. To assess the types and levels of exposure encountered by firefighters during their routine occupational duties, members of the Buffalo Fire Department were monitored during firefighting activities with personal, portable, ambient environmental sampling devices. The results indicate that firefighters are frequently exposed to significant concentrations of hazardous materials including carbon monoxide, benzene, sulphur dioxide, hydrogen cyanide, aldehydes, hydrogen chloride, dichlorofluoromethane, and particulates. Furthermore, in many cases of the worst exposure to these materials respiratory protective equipment was not used owing to the visual impression of low smoke intensity, and thus these levels represent actual direct exposure of the firefighters. Many of these materials have been implicated in the production of cardiovascular, respiratory, or neoplastic diseases, which may provide an explanation for the alleged increased risk for these illnesses among firefighters. PMID:3179235

  4. 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...

  5. Approaches to environmental exposure assessment in children.

    PubMed Central

    Weaver, V M; Buckley, T J; Groopman, J D

    1998-01-01

    An improved understanding of the contribution made by environmental exposures to disease burden in children is essential, given current increasing rates of childhood illnesses such asthma and cancer. Children must be routinely included in environmental research. Exposure assessment, both external (e.g., air, water) and internal dose (e.g., biomarkers), is an integral component of such research. Biomarker measurement has some advantages that are unique in children. These include assessment of potentially increased absorption because of behaviors that differ from adults (i.e., hand-to-mouth activity); metabolite measurement, which can help identify age-related susceptibility differences; and improved assessment of dermal exposure, an important exposure route in children. Environmental exposure assessment in children will require adaption of techniques that are currently applied in adult studies as well as development of tools and validation of strategies that are unique for children. Designs that focus on parent-child study units provide adult comparison data and allow the parent to assist with more complex study designs. Use of equipment that is sized appropriately for children, such as small air pumps and badge monitors, is also important. When biomarkers are used, biologic specimens that can be obtained noninvasively are preferable. Although the current need is primarily for small focused studies to address specific questions and optimize research tools, the future will require establishment of large prospective cohorts. Urban children are an important study cohort because of relatively high morbidity observed in the urban environment. Finally, examples of completed or possible future studies utilizing these techniques are discussed for specific exposures such as benzene, environmental tobacco smoke, aflatoxin, volatile organic compounds, and polycyclic aromatic hydrocarbons. PMID:9646045

  6. Clinical Assessment of Affective Instability: Comparing EMA Indices, Questionnaire Reports, and Retrospective Recall

    ERIC Educational Resources Information Center

    Solhan, Marika B.; Trull, Timothy J.; Jahng, Seungmin; Wood, Phillip K.

    2009-01-01

    Traditional self-report measures of psychopathology may be influenced by a variety of recall biases. Ecological momentary assessment (EMA) reduces these biases by assessing individuals' experiences as they occur in their natural environments. This study examines the discrepancy between trait questionnaire, retrospective report, and EMA measures of…

  7. 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

  8. 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).

  9. [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.

  10. 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...

  11. Direct and retrospective assessment of factors contributing to compulsive buying.

    PubMed

    Miltenberger, Raymond G; Redlin, Jennifer; Crosby, Ross; Stickney, Marcella; Mitchell, Jim; Wonderlich, Stephen; Faber, Ronald; Smyth, Joshua

    2003-03-01

    Compulsive buying is a disorder that has begun to receive attention from researchers in recent years. The results of a handful of studies suggest that compulsive buying occurs in response to negative emotions and results in a decrease in the intensity of the negative emotions. In this investigation, we used interview and self-monitoring methods to evaluate the antecedents and consequences of compulsive buying in a sample of women who met criteria for compulsive buying on the compulsive buying scale (J. Consumer Res. 19 (1992) 459). As a group, the participants reported negative emotions as the most common antecedents to compulsive buying, and euphoria or relief from the negative emotions as the most common consequence of compulsive buying. These findings were consistent across the interview and self-monitoring assessment methods. The implications for assessment and treatment are discussed. PMID:12763389

  12. Assessing occupational exposure to sea lamprey pesticides

    PubMed Central

    Ceballos, Diana M; Beaucham, Catherine C; Kurtz, Kristine; Musolin, Kristin

    2015-01-01

    Background: Sea lampreys are parasitic fish found in lakes of the United States and Canada. Sea lamprey is controlled through manual application of the pesticides 3-trifluoromethyl-4-nitrophenol (TFM) and BayluscideTM into streams and tributaries. 3-Trifluoromethyl-4-nitrophenol may cause irritation and central nervous system depression and Bayluscide may cause irritation, dermatitis, blisters, cracking, edema, and allergic skin reactions. Objectives: To assess occupational exposures to sea lamprey pesticides. Methods: We developed a wipe method for evaluating surface and skin contamination with these pesticides. This method was field tested at a biological field station and at a pesticide river application. We also evaluated exposures using control banding tools. Results: We verified TFM surface contamination at the biological station. At the river application, we found surfaces and worker’s skin contaminated with pesticides. Conclusion: We recommended minimizing exposures by implementing engineering controls and improved use of personal protective equipment. PMID:25730600

  13. Conceptual model for assessment of dermal exposure

    PubMed Central

    Schneider, T.; Vermeulen, R.; Brouwer, D. H.; Cherrie, J. W.; Kromhout, H.; Fogh, C. L.

    1999-01-01

    Dermal exposure, primarily to pesticides, has been measured for almost half a century. Compared with exposure by inhalation, limited progress has been made towards standardisation of methods of measurement and development of biologically relevant exposure measures. It is suggested that the absence of a consistent terminology and a theoretical model has been an important cause of this lack of progress. Therefore, a consistent terminology based on a multicompartment model for assessment of dermal exposure is proposed that describes the transport of contaminant mass from the source of the hazardous substance to the surface of the skin. Six compartments and two barriers together with eight mass transport processes are described. With the model structure, examples are given of what some existing methods actually measure and where there are limited, or no, methods for measuring the relevant mass in a compartment or transport of mass. The importance of measuring the concentration of contaminant and not mass per area in the skin contaminant layer is stressed, as it is the concentration difference between the skin contamination layer and the perfused tissue that drives uptake. Methods for measuring uptake are currently not available. Measurement of mass, concentration, and the transport processes must be based on a theoretical model. Standardisation of methods of measurement of dermal exposure is strongly recommended.   PMID:10658563

  14. A Formaldehyde Exposure Assessment Tool for Occupants of FEMA Temporary Housing Units

    SciTech Connect

    Parthasarathy, Srinandini; Spears, Michael; Maddalena, Randy L.; Russell, Marion L; Apte, Michael G.

    2010-10-01

    The report outlines the methodology used to develop a web-based tool to assess the formaldehyde exposure of the occupants of Federal Emergency Management Administration (FEMA) temporary housing units (THUs) after Hurricanes Katrina and Rita in 2005. Linear regression models were built using available data to retrospectively estimate the indoor temperature and relative humidity, formaldehyde emission factors and concentration, and hence the formaldehyde exposures. The interactive web-tool allows the user to define the inputs to the model to evaluate formaldehyde exposures for different scenarios.

  15. A Biomonitoring Framework to Support Exposure and Risk Assessments

    EPA Science Inventory

    Background - Biomonitoring is used in exposure and risk assessments to reduce uncertainties along the source-to-outcome continuum. Specifically, biomarkers can help identify exposure sources, routes, and distributions, and reflect kinetic and dynamic processes following exposure ...

  16. Retrospective performance assessment of the draft test guideline 426 on developmental neurotoxicity.

    EPA Science Inventory

    This document was created by an international panel under the auspices of the International Programme on Chemical Safety of the World Health Programme. The purpose and intent of this retrospective performance assessment document is to review the history of the developmen...

  17. Retrospective Assessment of Behavioral Inhibition in Infants and Toddlers: Development of a Parent Report Questionnaire

    ERIC Educational Resources Information Center

    Gensthaler, A.; Mohler, E.; Resch, F.; Paulus, F.; Schwenck, C.; Freitag, C. M.; Goth, K.

    2013-01-01

    A behaviorally inhibited temperament in early childhood has been identified as a potential risk factor for anxiety disorders in children and adolescents. The purpose of our investigation was the development and evaluation of the factor structure, reliability and validity of the first retrospective parent report measure to assess behavioral…

  18. Beginning Teacher Support and Assessment (BTSA) Progression: A Retrospective Account of BTSA's Response to English Learners

    ERIC Educational Resources Information Center

    Marquez-Lopez, Teresa I.; Oh, Deborah M.

    2010-01-01

    A retrospective account of the evolution of the Beginning Teacher Support and Assessment (BTSA) program shows how English learners and students of diverse cultural backgrounds were marginally considered throughout the development of the "California Standards for the Teaching Profession" and BTSA induction development, implementation, and…

  19. Exposure assessment of aluminum arc welding radiation.

    PubMed

    Peng, Chiung-yu; Lan, Cheng-hang; Juang, Yow-jer; Tsao, Ta-ho; Dai, Yu-tung; Liu, Hung-hsin; Chen, Chiou-jong

    2007-10-01

    The purpose of this study is to evaluate the non-ionizing radiation (NIR) exposure, especially optical radiation levels, and potential health hazard from aluminum arc welding processes based on the American Conference of Governmental Industrial Hygienists (ACGIH) method. The irradiance from the optical radiation emissions can be calculated with various biological effective parameters [i.e., S(lambda), B(lambda), R(lambda)] for NIR hazard assessments. The aluminum arc welding processing scatters bright light with NIR emission including ultraviolet radiation (UVR), visible, and infrared spectra. The UVR effective irradiance (Eeff) has a mean value of 1,100 microW cm at 100 cm distance from the arc spot. The maximum allowance time (tmax) is 2.79 s according to the ACGIH guideline. Blue-light hazard effective irradiance (EBlue) has a mean value of 1840 microW cm (300-700 nm) at 100 cm with a tmax of 5.45 s exposure allowance. Retinal thermal hazard effective calculation shows mean values of 320 mW cm(-2) sr(-1) and 25.4 mW (cm-2) (380-875 nm) for LRetina (spectral radiance) and ERetina (spectral irradiance), respectively. From this study, the NIR measurement from welding optical radiation emissions has been established to evaluate separate types of hazards to the eye and skin simultaneously. The NIR exposure assessment can be applied to other optical emissions from industrial sources. The data from welding assessment strongly suggest employees involved in aluminum welding processing must be fitted with appropriate personal protection devices such as masks and gloves to prevent serious injuries of the skin and eyes upon intense optical exposure.

  20. Clinical Assessment of Affective Instability: Comparing EMA indices, questionnaire reports, and retrospective recall

    PubMed Central

    Solhan, Marika B.; Trull, Timothy J.; Jahng, Seungmin; Wood, Phillip K.

    2010-01-01

    Traditional self-report measures of psychopathology may be influenced by a variety of recall biases. Ecological momentary assessment (EMA) reduces these biases by assessing individuals' experiences as they occur in their natural environments. This study examines the discrepancy between trait questionnaire, retrospective report, and EMA measures of affective instability in psychiatric outpatients either with a borderline personality diagnosis (BPD; n=58) or with a current major depressive episode or dysthymia (MDD/DYS; n=42). We examined the agreement of three trait measures of affective instability (Personality Assessment Inventory-Borderline Features scale – Affective Instability scale, Affect Intensity Measure, and the Affect Lability Scales) and one retrospective mood recall task with EMA indices of mood and mood instability. Results indicate only modest to moderate agreement between momentary and questionnaire assessments of trait affective instability; agreement between recalled mood changes and EMA indices was poor. Implications for clinical research and practice and possible applications of EMA methodology are discussed. PMID:19719353

  1. 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...

  2. 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...

  3. What's the Use of Faculty Development? Program Evaluation Using Retrospective Self-Assessments and Independent Performance Ratings.

    ERIC Educational Resources Information Center

    Hewson, Mariana G.; Copeland, H. Liesel; Fishleder, Andrew J.

    2001-01-01

    Investigated the usefulness of retrospective self-assessments by participants in a faculty development program in combination with independent ratings of their teaching performance by their trainees. Found that both the retrospective self-assessments and the independent ratings by trainees showed post-program improvements and were positively…

  4. Stillbirth and neonatal death in relation to radiation exposure before conception: a retrospective cohort study

    PubMed Central

    Signorello, Lisa B; Mulvihill, John J; Green, Daniel M; Munro, Heather M; Stovall, Marilyn; Weathers, Rita E; Mertens, Ann C; Whitton, John A; Robison, Leslie L; Boice, John D

    2010-01-01

    Summary Background The reproductive implications of mutagenic treatments given to children with cancer are not clear. By studying the risk of untoward pregnancy outcomes, we indirectly assessed the risk of transmission of germline damage to the offspring of survivors of childhood cancer who were given radiotherapy and chemotherapy. Methods We did a retrospective cohort analysis, within the Childhood Cancer Survivor Study (CCSS), of the risk of stillbirth and neonatal death among the offspring of men and women who had survived childhood cancer. Patients in CCSS were younger than 21 years at initial diagnosis of an eligible cancer, were treated at 25 US institutions and one Canadian institution, and had survived for at least 5 years after diagnosis. We quantified the chemotherapy given to patients, and the preconception radiation doses to the testes, ovaries, uterus, and pituitary gland, and related these to the risk of stillbirth or neonatal death using Poisson regression analysis. Findings Among 1148 men and 1657 women who had survived childhood cancer, there were 4946 pregnancies. Irradiation of the testes (16 [1%] of 1270; adjusted relative risk 0·8 [95% CI 0·4–1·6]; mean dose 0·53 Gy [SD 1·40]) and pituitary gland (17 [3%] of 510, 1·1 [0·5–2·4] for more than 20·00 Gy; mean dose 10·20 Gy [13·0] for women), and chemotherapy with alkylating drugs (26 [2%] of 1195 women, 0·9 [0·5–1·5]; ten [1%] of 732 men, 1·2 [0·5–2·5]) were not associated with an increased risk of stillbirth or neonatal death. Uterine and ovarian irradiation significantly increased risk of stillbirth and neonatal death at doses greater than 10·00 Gy (five [18%] of 28, 9·1 [3·4–24·6]). For girls treated before menarche, irradiation of the uterus and ovaries at doses as low as 1·00–2·49 Gy significantly increased the risk of stillbirth or neonatal death (three [4%] of 69, 4·7 [1·2–19·0]). Interpretation Our findings do not support concern about heritable

  5. 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

  6. 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

    Carbon dioxide (CO2) is an anthropogenic gas that accumulates in spacecraft to much higher levels than earth-normal levels. Controlling concentrations of this gas to acceptable levels to ensure crew health and optimal performance demands major commitment of resources. NASA has many decades of experience monitoring and controlling CO2, yet we are uncertain of the levels at which subtle performance decrements develop. There is limited evidence from ground-based studies that visual disturbances can occur during brief exposures and visual changes have been noted in spaceflight crews. These changes may be due to CO2 alone or in combination with other known spaceflight factors such as increased intracranial pressure due to fluid shifts. Discerning the comparative contribution of each to performance decrements is an urgent issue if we hope to optimize astronaut performance aboard the ISS. Long-term, we must know the appropriate control levels for exploration-class missions to ensure that crewmembers can remain cooperative and productive in a highly stressful environment. Furthermore, we must know the magnitude of interindividual variability in susceptibility to the adverse effects of CO2 so that the most tolerant crewmembers can be identified. Ground-based studies have been conducted for many years to set exposure limits for submariners; however, these studies are typically limited and incompletely reported. Nonetheless, NASA, in cooperation with the National Research Council, has set exposure limits for astronauts using this limited database. These studies do not consider the interactions of spaceflight-induced fluid shifts and CO2 exposures. In an attempt to discern whether CO2 levels affect the incidence of headache and visual disturbances in astronauts we performed a retrospective study comparing average CO2 levels and the prevalence of headache and visual disturbances. Our goal is to narrow gaps in the risk profile for in-flight CO2 exposures. Such studies can

  7. Occurrence of mental illness following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study

    PubMed Central

    2012-01-01

    Background While many studies of adults with solvent exposure have shown increased risks of anxiety and depressive disorders, there is little information on the impact of prenatal and early childhood exposure on the subsequent risk of mental illness. This retrospective cohort study examined whether early life exposure to tetrachloroethylene (PCE)-contaminated drinking water influenced the occurrence of depression, bipolar disorder, post-traumatic stress disorder, and schizophrenia among adults from Cape Cod, Massachusetts. Methods A total of 1,512 subjects born between 1969 and 1983 were studied, including 831 subjects with both prenatal and early childhood PCE exposure and 547 unexposed subjects. Participants completed questionnaires to gather information on mental illnesses, demographic and medical characteristics, other sources of solvent exposure, and residences from birth through 1990. PCE exposure originating from the vinyl-liner of water distribution pipes was assessed using water distribution system modeling software that incorporated a leaching and transport algorithm. Results No meaningful increases in risk ratios (RR) for depression were observed among subjects with prenatal and early childhood exposure (RR: 1.1, 95% CI: 0.9-1.4). However, subjects with prenatal and early childhood exposure had a 1.8-fold increased risk of bipolar disorder (N = 36 exposed cases, 95% CI: 0.9-1.4), a 1.5-fold increased risk post-traumatic stress disorder (N = 47 exposed cases, 95% CI: 0.9-2.5), and a 2.1-fold increased risk of schizophrenia (N = 3 exposed cases, 95% CI: 0.2-20.0). Further increases in the risk ratio were observed for bipolar disorder (N = 18 exposed cases, RR; 2.7, 95% CI: 1.3-5.6) and post-traumatic stress disorder (N = 18 exposed cases, RR: 1.7, 95% CI: 0.9-3.2) among subjects with the highest exposure levels. Conclusions The results of this study provide evidence against an impact of early life exposure to PCE on the risk of depression. In contrast, the

  8. Occupational exposure to environmental tobacco smoke and health risk assessment.

    PubMed Central

    Jaakkola, M S; Samet, J M

    1999-01-01

    This article addresses concepts of environmental tobacco smoke (ETS) exposure assessment relevant for health risk assessment based on human studies. We present issues that should be considered when selecting a method for ETS exposure assessment for the purposes of health risk assessment and review data on ETS exposure levels in the workplace and in home environments. Two types of estimates are needed for a quantitative risk assessment of the health effects resulting from occupational ETS exposure: (italic)a(/italic)) an unbiased estimate of the exposure-effect (or dose-response) relation between ETS and the health effect of interest, and (italic)b(/italic)) estimates of the distribution of ETS exposure in different workplaces. By combining the estimated exposure-effect relation with information on exposure distribution for a population of interest, we can calculate the proportions of disease cases attributable to occupational ETS exposure as well as the excess number of cases due to specified exposure conditions. Several dimensions of the exposure profile should be considered when assessing ETS exposure for estimating the exposure-effect relation, including the magnitude of exposure and the biologically relevant time specificity of exposure. The magnitude of exposure is determined by the ETS source strength, environmental factors modifying concentrations, and duration of exposure. Time specificity considerations include the latency period for each health outcome of interest, the time-exposure profile relevant for different disease mechanisms, and the sensitive age period with regard to health effects. The most appropriate indicator of ETS exposure depends on these factors and on the time period that can be assessed with different methods. Images Figure 1 Figure 3 Figure 4 PMID:10592138

  9. 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...

  10. 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.

  11. 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...

  12. 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 ...

  13. 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...

  14. Prenatal exposure to tetrachloroethylene-contaminated drinking water and the risk of congenital anomalies: a retrospective cohort study

    PubMed Central

    2009-01-01

    Background Prior animal and human studies of prenatal exposure to solvents including tetrachloroethylene (PCE) have shown increases in the risk of certain congenital anomalies among exposed offspring. Objectives This retrospective cohort study examined whether PCE contamination of public drinking water supplies in Massachusetts influenced the occurrence of congenital anomalies among children whose mothers were exposed around the time of conception. Methods The study included 1,658 children whose mothers were exposed to PCE-contaminated drinking water and a comparable group of 2,999 children of unexposed mothers. Mothers completed a self-administered questionnaire to gather information on all of their prior births, including the presence of anomalies, residential histories and confounding variables. PCE exposure was estimated using EPANET water distribution system modeling software that incorporated a fate and transport model. Results Children whose mothers had high exposure levels around the time of conception had an increased risk of congenital anomalies. The adjusted odds ratio of all anomalies combined among children with prenatal exposure in the uppermost quartile was 1.5 (95% CI: 0.9, 2.5). No meaningful increases in the risk were seen for lower exposure levels. Increases were also observed in the risk of neural tube defects (OR: 3.5, 95% CI: 0.8, 14.0) and oral clefts (OR 3.2, 95% CI: 0.7, 15.0) among offspring with any prenatal exposure. Conclusion The results of this study suggest that the risk of certain congenital anomalies is increased among the offspring of women who were exposed to PCE-contaminated drinking water around the time of conception. Because these results are limited by the small number of children with congenital anomalies that were based on maternal reports, a follow-up investigation should be conducted with a larger number of affected children who are identified by independent records. PMID:19778411

  15. 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

  16. 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.

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

    PubMed

    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

  18. Retrospective assessment of behavioral inhibition in infants and toddlers: development of a parent report questionnaire.

    PubMed

    Gensthaler, A; Möhler, E; Resch, F; Paulus, F; Schwenck, C; Freitag, C M; Goth, K

    2013-02-01

    A behaviorally inhibited temperament in early childhood has been identified as a potential risk factor for anxiety disorders in children and adolescents. The purpose of our investigation was the development and evaluation of the factor structure, reliability and validity of the first retrospective parent report measure to assess behavioral inhibition in infants and toddlers. Principal Component Analysis of the Retrospective Infant Behavioral Inhibition Scale (RIBI) supported a three factor solution of the core features of BI in two unselected samples. Internal consistency and inter-rater agreement of both parent judgments were >.90 and >.70. Scores of the RIBI were positively correlated with the parent report temperament questionnaire IBQ and a laboratory-based test at age 14 months with the child. PMID:22798203

  19. 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.

  20. Implications of uncertainty in exposure assessment for groundwater contamination

    USGS Publications Warehouse

    Reichard, Eric G.; Izbicki, John A.; Martin, Peter

    1995-01-01

    Decision-making on regulation, mitigation, and treatment of drinking water contamination depends, in part, on estimates of human exposure. Assessment of past, present and potential future exposure levels requires quantitative characterization of the contaminant sources, the transport of contaminants and the level of actual human exposure to the contaminated water. Failure to consider the uncertainties in these three components of exposure assessment can lead to poor decisions such as implementing an inappropriate mitigation strategy or failing to regulate an important contaminant. Three examples from US Geological Survey hydrogeologic studies in southern California are presented to illustrate some of the unique uncertainties associated with exposure assessment for groundwater contamination.

  1. Exposure Reconstruction: A Framework of Advancing Exposure Assessment

    EPA Science Inventory

    The U.S. Environmental Protection Agency’s (EPA) primary goal for environmental protection is to eliminate or minimize the exposure of humans and ecosystems to potential contaminants. With the number of environmental contaminants increasing annually – more than 2000 new chemical...

  2. Retrospective Exposure Estimation and Predicted versus Observed Serum Perfluorooctanoic Acid Concentrations for Participants in the C8 Health Project

    PubMed Central

    Vieira, Verónica M.; Ryan, P. Barry; Steenland, Kyle; Bartell, Scott M.

    2011-01-01

    Background: People living or working in eastern Ohio and western West Virginia have been exposed to perfluorooctanoic acid (PFOA) released by DuPont Washington Works facilities. Objectives: Our objective was to estimate historical PFOA exposures and serum concentrations experienced by 45,276 non-occupationally exposed participants in the C8 Health Project who consented to share their residential histories and a 2005–2006 serum PFOA measurement. Methods: We estimated annual PFOA exposure rates for each individual based on predicted calibrated water concentrations and predicted air concentrations using an environmental fate and transport model, individual residential histories, and maps of public water supply networks. We coupled individual exposure estimates with a one-compartment absorption, distribution, metabolism, and excretion (ADME) model to estimate time-dependent serum concentrations. Results: For all participants (n = 45,276), predicted and observed median serum concentrations in 2005–2006 are 14.2 and 24.3 ppb, respectively [Spearman’s rank correlation coefficient (rs) = 0.67]. For participants who provided daily public well water consumption rate and who had the same residence and workplace in one of six municipal water districts for 5 years before the serum sample (n = 1,074), predicted and observed median serum concentrations in 2005–2006 are 32.2 and 40.0 ppb, respectively (rs = 0.82). Conclusions: Serum PFOA concentrations predicted by linked exposure and ADME models correlated well with observed 2005–2006 human serum concentrations for C8 Health Project participants. These individualized retrospective exposure and serum estimates are being used in a variety of epidemiologic studies being conducted in this region. PMID:21813367

  3. Clinical assessment of affective instability: comparing EMA indices, questionnaire reports, and retrospective recall.

    PubMed

    Solhan, Marika B; Trull, Timothy J; Jahng, Seungmin; Wood, Phillip K

    2009-09-01

    Traditional self-report measures of psychopathology may be influenced by a variety of recall biases. Ecological momentary assessment (EMA) reduces these biases by assessing individuals' experiences as they occur in their natural environments. This study examines the discrepancy between trait questionnaire, retrospective report, and EMA measures of affective instability in psychiatric outpatients either with a borderline personality diagnosis (n = 58) or with a current episode of major depressive disorder or dysthymia (n = 42). The authors examined the agreement of 3 trait measures of affective instability-the Affective Instability subscale of the Personality Assessment Inventory-Borderline Features scale (L. C. Morey, 1991), the Affect Intensity Measure (R. J. Larsen, E. Diener, & R. Emmons, 1986), and the Affect Lability Scales (P. D. Harvey, B. R. Greenberg, & M. R. Serper, 1989)-and 1 retrospective mood recall task with EMA indices of mood and mood instability. Results indicate only modest to moderate agreement between momentary and questionnaire assessments of trait affective instability; agreement between recalled mood changes and EMA indices was poor. Implications for clinical research and practice and possible applications of EMA methodology are discussed.

  4. [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. PMID:11828845

  5. Malaria Eradication in the Americas: A Retrospective Analysis of Childhood Exposure*

    PubMed Central

    Bleakley, Hoyt

    2013-01-01

    This study uses the malaria-eradication campaigns in the United States (circa 1920), and in Brazil, Colombia and Mexico (circa 1955) to measure how much childhood exposure to malaria depresses labor productivity. The campaigns began because of advances in health technology, which mitigates concerns about reverse causality. Malarious areas saw large drops in the disease thereafter. Relative to non-malarious areas, cohorts born after eradication had higher income as adults than the preceding generation. These cross-cohort changes coincided with childhood exposure to the campaigns rather than to pre-existing trends. Estimates suggest a substantial, though not predominant, role for malaria in explaining cross-region differences in income. PMID:24179596

  6. [Retrospective evaluation of occupational exposure in epidemiologic studies. Use of the Delphi method].

    PubMed

    Goldberg, M; Leclerc, A; Chastang, J F; Goldberg, P; Brodeur, J M; Fuhrer, R; Segnan, N

    1986-01-01

    A method, based on the Delphi technique, for evaluating occupational risks in a quantifiable manner was devised in the course of a case-control study on respiratory cancers in the nickel mining and refining industry in New Caledonia. There were four stages in the evaluation process: identification of eleven potential carcinogenic factors in the company during the 1930-1977 period; grouping of a limited number of work-stations; evaluation of exposure levels for the different factors for each workstation; computation of the cumulative value of exposure for each subject under study. A partial validation study shows that this kind of approach may prove useful for future occupational epidemiological studies. PMID:3547516

  7. Radiation exposure in the young level 1 trauma patient: a retrospective review.

    PubMed

    Gottschalk, Michael B; Bellaire, Laura L; Moore, Thomas

    2015-01-01

    Computed tomography (CT) has become an increasingly popular and powerful tool for clinicians managing trauma patients with life-threatening injuries, but the ramifications of increasing radiation burden on individual patients are not insignificant. This study examines a continuous series of 337 patients less than 40 years old admitted to a level 1 trauma center during a 4-month period. Primary outcome measures included number of scans; effective dose of radiation from radiographs and CT scans, respectively; and total effective dose from both sources over patients' hospital stays. Several variables, including hospital length of stay, initial Glasgow Coma Scale score, and Injury Severity Score, correlated with greater radiation exposure. Blunt trauma victims were more prone to higher doses than those with penetrating or combined penetrating and blunt trauma. Location and mechanism of injury were also found to correlate with radiation exposure. Trauma patients as a group are exposed to high levels of radiation from X-rays and CT scans, and CT scans contribute a very high proportion (91.3% ± 11.7%) of that radiation. Certain subgroups of patients are at a particularly high risk of exposure, and greater attention to cumulative radiation dose should be paid to patients with the above mentioned risk factors.

  8. 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.

  9. 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...

  10. Summary of retrospective asbestos and welding fume exposure estimates for a nuclear naval shipyard and their correlation with radiation exposure estimates.

    PubMed

    Zaebst, D D; Seel, E A; Yiin, J H; Nowlin, S J; Chen, P

    2009-07-01

    In support of a nested case-control study at a U.S. naval shipyard, the results of the reconstruction of historical exposures were summarized, and an analysis was undertaken to determine the impact of historical exposures to potential chemical confounders. The nested case-control study (N = 4388) primarily assessed the relationship between lung cancer and external ionizing radiation. Chemical confounders considered important were asbestos and welding fume (as iron oxide fume), and the chromium and nickel content of welding fume. Exposures to the potential confounders were estimated by an expert panel based on a set of quantitatively defined categories of exposure. Distributions of the estimated exposures and trends in exposures over time were examined for the study population. Scatter plots and Spearman rank correlation coefficients were used to assess the degree of association between the estimates of exposure to asbestos, welding fume, and ionizing radiation. Correlation coefficients were calculated separately for 0-, 15-, 20-, and 25-year time-lagged cumulative exposures, total radiation dose (which included medical X-ray dose) and occupational radiation dose. Exposed workers' estimated cumulative exposures to asbestos ranged from 0.01 fiber-days/cm(3) to just under 20,000 fiber-days/cm(3), with a median of 29.0 fiber-days/cm(3). Estimated cumulative exposures to welding fume ranged from 0.16 mg-days/m(3) to just over 30,000 mg-days/m(3), with a median of 603 mg-days/m(3). Spearman correlation coefficients between cumulative radiation dose and cumulative asbestos exposures ranged from 0.09 (occupational dose) to 0.47 (total radiation dose), and those between radiation and welding fume from 0.14 to 0.47. The estimates of relative risk for ionizing radiation and lung cancer were unchanged when lowest and highest estimates of asbestos and welding fume were considered. These results suggest a fairly large proportion of study population workers were exposed to

  11. Assessing Children's Exposure to Intimate Partner Violence

    ERIC Educational Resources Information Center

    Knutson, John F.; Lawrence, Erika; Taber, Sarah M.; Bank, Lew; DeGarmo, David S.

    2009-01-01

    Child exposure to intimate partner violence (IPV) is widely acknowledged as a threat to the psycho-social and academic well-being of children. Unfortunately, as reflected in the literature, the specific link between such exposure and childhood outcomes is ambiguous. Based on a review of the literature, this article suggests that this state of…

  12. Assessment of Violence Exposure among Residential Children and Adolescents

    ERIC Educational Resources Information Center

    Singer, Mark I.

    2007-01-01

    Childhood victimization is an important factor in assessing children in residential treatment. These children often have extensive histories of abuse and neglect, and are of high risk for violence exposure in their schools and neighborhoods. This article describes the concept of exposure to community violence, and its importance in assessing and…

  13. Determination of Neutron Exposure of AISI 304 Stainless Steel from a BWR Top Guide using Retrospective Dosimetry

    SciTech Connect

    Greenwood, Lawrence R.; Garner, Francis A.; Oliver, Brian M.; Bruemmer, Stephen M.

    2007-03-31

    Retrospective dosimetry was used to determine the accumulated neutron exposure of AISI 304 stainless steel removed from the top guide of a boiling water reactor located at the Oyster Creek nuclear power station. The material was removed from areas adjacent to cracks that were observed after ~20 years of operation. Using the plant operational history and a variety of measurements of various radioisotopes or non-radioactive transmutation products produced by irradiation, it was possible to determine the integrated flux spectra experienced by the cracked region and to specify the accumulated displacement dose. Dose estimates on two separate specimens adjacent to the cracks were found to average 1.5 ± 0.2 dpa, possibly reflecting some uncertainty in measurement but more likely suggesting a small gradient in neutron flux-spectra within the section from which the various analysis specimens were cut. This report demonstrates that it is possible to examine defective components lying outside of the core region and where neutron flux-spectra are not well known, and to use the induced transmutation products to determine the neutron exposure with some confidence by using the examined specimen as its own dosimeter.

  14. Retrospective analysis of a listeria monocytogenes contamination episode in raw milk goat cheese using quantitative microbial risk assessment tools.

    PubMed

    Delhalle, L; Ellouze, M; Yde, M; Clinquart, A; Daube, G; Korsak, N

    2012-12-01

    In 2005, the Belgian authorities reported a Listeria monocytogenes contamination episode in cheese made from raw goat's milk. The presence of an asymptomatic shedder goat in the herd caused this contamination. On the basis of data collected at the time of the episode, a retrospective study was performed using an exposure assessment model covering the production chain from the milking of goats up to delivery of cheese to the market. Predictive microbiology models were used to simulate the growth of L. monocytogenes during the cheese process in relation with temperature, pH, and water activity. The model showed significant growth of L. monocytogenes during chilling and storage of the milk collected the day before the cheese production (median increase of 2.2 log CFU/ml) and during the addition of starter and rennet to milk (median increase of 1.2 log CFU/ml). The L. monocytogenes concentration in the fresh unripened cheese was estimated to be 3.8 log CFU/g (median). This result is consistent with the number of L. monocytogenes in the fresh cheese (3.6 log CFU/g) reported during the cheese contamination episode. A variance-based method sensitivity analysis identified the most important factors impacting the cheese contamination, and a scenario analysis then evaluated several options for risk mitigation. Thus, by using quantitative microbial risk assessment tools, this study provides reliable information to identify and control critical steps in a local production chain of cheese made from raw goat's milk.

  15. Benzalkonium chloride exposure in cats: a retrospective analysis of 245 cases reported to the Veterinary Poisons Information Service (VPIS).

    PubMed

    Bates, N; Edwards, N

    2015-02-28

    Benzalkonium chloride is commonly found in household products. This retrospective study examined 245 cases of feline exposure to benzalkonium chloride-containing products reported to the Veterinary Poisons Information Service (VPIS). A single route of exposure was reported in 188 cats (ingestion 126, skin 58, buccal 4); 57 cats had multiple routes. The common products involved were household antibacterial cleaners (43.6 per cent), household disinfectants (22.3 per cent) and patio cleaners (17.5 per cent). The most common signs were hypersalivation/drooling (53.9 per cent), tongue ulceration (40.4 per cent), hyperthermia (40.4 per cent) and oral ulceration (22.9 per cent). The mean time recorded for onset of the first clinical sign was 6.4 hours (range five minutes to 48 hours, median 4.5 hours, n=60), however, the VPIS was not contacted until 14.0 ± 13.2 hours after exposure (n=120). This figure also reflects the time of presentation. The most common treatments given were antibiotics (82.0 per cent), fluids (50.2 per cent), analgesia (45.3 per cent), gastroprotectants (31.0 per cent), dermal decontamination (24.1 per cent) and steroids (22.7 per cent). 13 cats (5.3 per cent) received syringe or nasogastric feeding. Of 245 cats, 12 (4.9 per cent) remained asymptomatic, 230 (93.9 per cent) recovered and three died (1.2 per cent). The time to recovery ranged from 1 to 360 hours (n=67) with a mean of 100.4 ± 82.0 hours (4.2 ± 3.4 days, median 72 hours).

  16. 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

  17. 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. PMID:12505908

  18. Exposure Assessment in Cohort Studies of Childhood Asthma

    PubMed Central

    Arrandale, Victoria H.; Brauer, Michael; Brook, Jeffrey R.; Brunekreef, Bert; Gold, Diane R.; London, Stephanie J.; Miller, J. David; Özkaynak, Halûk; Ries, Nola M.; Sears, Malcolm R.; Silverman, Frances S.; Takaro, Tim K.

    2011-01-01

    Background The environment is suspected to play an important role in the development of childhood asthma. Cohort studies are a powerful observational design for studying exposure–response relationships, but their power depends in part upon the accuracy of the exposure assessment. Objective The purpose of this paper is to summarize and discuss issues that make accurate exposure assessment a challenge and to suggest strategies for improving exposure assessment in longitudinal cohort studies of childhood asthma and allergies. Data synthesis Exposures of interest need to be prioritized, because a single study cannot measure all potentially relevant exposures. Hypotheses need to be based on proposed mechanisms, critical time windows for effects, prior knowledge of physical, physiologic, and immunologic development, as well as genetic pathways potentially influenced by the exposures. Modifiable exposures are most important from the public health perspective. Given the interest in evaluating gene–environment interactions, large cohort sizes are required, and planning for data pooling across independent studies is critical. Collection of additional samples, possibly through subject participation, will permit secondary analyses. Models combining air quality, environmental, and dose data provide exposure estimates across large cohorts but can still be improved. Conclusions Exposure is best characterized through a combination of information sources. Improving exposure assessment is critical for reducing measurement error and increasing power, which increase confidence in characterization of children at risk, leading to improved health outcomes. PMID:21081299

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

    PubMed

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

    2011-01-01

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

  20. Advanced REACH Tool: a Bayesian model for occupational exposure assessment.

    PubMed

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

    2014-06-01

    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. PROBABILISTIC MODELING FOR ADVANCED HUMAN EXPOSURE ASSESSMENT

    EPA Science Inventory

    Human exposures to environmental pollutants widely vary depending on the emission patterns that result in microenvironmental pollutant concentrations, as well as behavioral factors that determine the extent of an individual's contact with these pollutants. Probabilistic human exp...

  2. 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.

  3. 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.

  4. High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function.

    PubMed

    Coolen, Bram F; Abdurrachim, Desiree; Motaal, Abdallah G; Nicolay, Klaas; Prompers, Jeanine J; Strijkers, Gustav J

    2013-03-01

    To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered at will to increase the frame rate because of gradient hardware, spatial resolution, and signal-to-noise limitations. To overcome these limitations associated with electrocardiography-triggered Cine MRI, in this paper, we introduce a retrospectively triggered Cine MRI protocol capable of producing high-resolution high frame rate Cine MRI of the mouse heart for addressing left ventricular diastolic function. Simulations were performed to investigate the influence of MRI sequence parameters and the k-space filling trajectory in relation to the desired number of frames per cardiac cycle. An optimized protocol was applied in vivo and compared with electrocardiography-triggered Cine for which a high-frame rate could only be achieved by several interleaved acquisitions. Retrospective high frame rate Cine MRI proved superior to the interleaved electrocardiography-triggered protocols. High spatial-resolution Cine movies with frames rates up to 80 frames per cardiac cycle were obtained in 25 min. Analysis of left ventricular filling rate curves allowed accurate determination of early and late filling rates and revealed subtle impairments in left ventricular diastolic function of diabetic mice in comparison with nondiabetic mice.

  5. Retrospective assessment of dryland soil stability in relation to grazing and climate change.

    PubMed

    Washington-Allen, Robert A; West, Neil E; Ramsey, R Douglas; Phillips, Debra H; Shugart, Herman H

    2010-01-01

    Accelerated soil erosion is an aspect of dryland degradation that is affected by repeated intense drought events and land management activities such as commercial livestock grazing. A soil stability index (SSI) that detects the erosion status and susceptibility of a landscape at the pixel level, i.e., stable, erosional, or depositional pixels, was derived from the spectral properties of an archived time series (from 1972 to 1997) of Landsat satellite data of a commercial ranch in northeastern Utah. The SSI was retrospectively validated with contemporary field measures of soil organic matter and erosion status that was surveyed by US federal land management agencies. Catastrophe theory provided the conceptual framework for retrospective assessment of the impact of commercial grazing and soil water availability on the SSI. The overall SSI trend was from an eroding landscape in the early drier 1970s towards stable conditions in the wetter mid-1980s and late 1990s. The landscape catastrophically shifted towards an extreme eroding state that was coincident with the "The Great North American Drought of 1988". Periods of landscape stability and trajectories toward stability were coincident with extremely wet El Niño events. Commercial grazing had less correlation with soil stability than drought conditions. However, the landscape became more susceptible to erosion events under multiple droughts and grazing. Land managers now have nearly a year warning of El Niño and La Niña events and can adjust their management decisions according to predicted landscape erosion conditions. PMID:19130278

  6. Application of statistical modeling to occupational exposure assessment

    SciTech Connect

    Nicas, M.

    1991-01-01

    This dissertation applies statistical modeling to two problems: (1) describing a single worker's exposure distribution and estimating its associated arithemetic mean; and (2) describing the distribution of inhalation exposure levels among a population of respirator wearers while accounting for variability in ambient exposure and respirator penetration values within and between wearers. A task-based statistical construct for a single worker's exposure levels for a single agent is developed; the model accounts for variability in short-term time weighted average (TWA) exposure values within a task, and for variability in arithmetic mean exposure levels between tasks. Five sample survey designs for estimating a worker's arithmetic mean exposure level are examined. Stratified random sampling designs, in which short-term TWAs are measured for time periods selected on a task basis, can provide a more precise estimate of the arithmetic mean exposure level than the traditional survey design for the same fixed cost. For describing inhalation exposure levels (C{sub i}) among a population of air-purifying respirator wearers, a synthesis of lognormal one-way analysis of variance models for ambient exposure levels (C.) and respirator penetration (P) values provides the most tractable construct. The model is applied to assessing the risk of toxicant overexposure for a respirator wearer population. Overexposure to a chronic toxicant is equated with an arithmetic mean exposure level above the permissible exposure limit (PEL) value, while overexposure to an acute toxicant is equated with a 95th percentile exposure level above the PEL value.

  7. 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. PMID:24447976

  8. 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.

  9. Accuracy of a semiquantitative method for Dermal Exposure Assessment (DREAM)

    PubMed Central

    van Wendel, de Joo... B; Vermeulen, R; van Hemmen, J J; Fransman, W; Kromhout, H

    2005-01-01

    Background: The authors recently developed a Dermal Exposure Assessment Method (DREAM), an observational semiquantitative method to assess dermal exposures by systematically evaluating exposure determinants using pre-assigned default values. Aim: To explore the accuracy of the DREAM method by comparing its estimates with quantitative dermal exposure measurements in several occupational settings. Methods: Occupational hygienists observed workers performing a certain task, whose exposure to chemical agents on skin or clothing was measured quantitatively simultaneously, and filled in the DREAM questionnaire. DREAM estimates were compared with measurement data by estimating Spearman correlation coefficients for each task and for individual observations. In addition, mixed linear regression models were used to study the effect of DREAM estimates on the variability in measured exposures between tasks, between workers, and from day to day. Results: For skin exposures, spearman correlation coefficients for individual observations ranged from 0.19 to 0.82. DREAM estimates for exposure levels on hands and forearms showed a fixed effect between and within surveys, explaining mainly between-task variance. In general, exposure levels on clothing layer were only predicted in a meaningful way by detailed DREAM estimates, which comprised detailed information on the concentration of the agent in the formulation to which exposure occurred. Conclusions: The authors expect that the DREAM method can be successfully applied for semiquantitative dermal exposure assessment in epidemiological and occupational hygiene surveys of groups of workers with considerable contrast in dermal exposure levels (variability between groups >1.0). For surveys with less contrasting exposure levels, quantitative dermal exposure measurements are preferable. PMID:16109819

  10. Assessing the Validity of Can-Do Statements in Retrospective (Then-Now) Self-Assessment

    ERIC Educational Resources Information Center

    Brown, N. Anthony; Dewey, Dan P.; Cox, Troy L.

    2014-01-01

    In this study, the authors evaluated the strengths and limitations of a self-assessment based on ACTFL Can-Do statements ("ACTFL," 2013]) as a tool for measuring linguistic gains over an internship abroad in Russia. They assessed its reliability, determined how its items mapped with the ACTFL scale, and measured the degree to which…

  11. The Collaborative Assessment and Management of Suicidality versus Treatment as Usual: A Retrospective Study with Suicidal Outpatients

    ERIC Educational Resources Information Center

    Jobes, David A.; Wong, Steven A.; Conrad, Amy K.; Drozd, John F.; Neal-Walden, Tracy

    2005-01-01

    The Collaborative Assessment and Management of Suicidality (CAMS) is a novel clinical approach used to identify, assess, and manage suicidal outpatients (Jobes & Drozd, 2004). The results of a retrospective study evaluating the impact of CAMS versus treatment as usual (TAU) on suicidal outpatients are presented. Patients in the CAMS treatment…

  12. Assessing the risks from exposure to radon in dwellings

    SciTech Connect

    Walsh, P.J.; Lowder, W.M.

    1983-07-01

    The factors used to assess the radiation dose and health risks from human exposure to radon in dwellings are critically reviewed in this summary. Sources of indoor radon and determinants of air concentrations and exposure levels are given as well as the uncertainties that exist in their formulation. Methods of assessing health effects from inhalation of radon and its progeny are discussed with emphasis on dosimetry of radon daughters and formulation of risk per dose values. Finally, methods of assessing risks for general population exposures to indoor radon concentrations are treated.

  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. 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...

  15. The Stateville penitentiary malaria experiments: a case study in retrospective ethical assessment.

    PubMed

    Miller, Franklin G

    2013-01-01

    During World War II, malaria research was conducted in prisons. A notable example was the experiments at Stateville Penitentiary in Illinois, in which prisoner-subjects were infected with malaria for the purpose of testing the safety and efficacy of novel anti-malaria drugs. Over time, commentators have shifted from viewing the malaria research at Stateville as a model of ethical clinical research to seeing the experiments as paradigmatic of abusive human experimentation. This essay undertakes a retrospective ethical assessment of the Stateville malaria research during the 1940s in light of basic ethical principles and the Nuremberg Code, as well as contemporary malaria research. In addition to its historical interest, this case study provides a rich context for addressing basic issues of research ethics, including the voluntariness of consent, the justification of risks, and the exploitation of vulnerable subjects. PMID:24769747

  16. Quantitative Framework for Retrospective Assessment of Interim Decisions in Clinical Trials

    PubMed Central

    Stanev, Roger

    2016-01-01

    This article presents a quantitative way of modeling the interim decisions of clinical trials. While statistical approaches tend to focus on the epistemic aspects of statistical monitoring rules, often overlooking ethical considerations, ethical approaches tend to neglect the key epistemic dimension. The proposal is a second-order decision-analytic framework. The framework provides means for retrospective assessment of interim decisions based on a clear and consistent set of criteria that combines both ethical and epistemic considerations. The framework is broadly Bayesian and addresses a fundamental question behind many concerns about clinical trials: What does it take for an interim decision (e.g., whether to stop the trial or continue) to be a good decision? Simulations illustrating the modeling of interim decisions counterfactually are provided. PMID:27353825

  17. 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

  18. 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

  19. Assessing therapist reservations about exposure therapy for anxiety disorders: the Therapist Beliefs about Exposure Scale.

    PubMed

    Deacon, Brett J; Farrell, Nicholas R; Kemp, Joshua J; Dixon, Laura J; Sy, Jennifer T; Zhang, Annie R; McGrath, Patrick B

    2013-12-01

    Exposure therapy is underutilized in the treatment of pathological anxiety and is often delivered in a suboptimal manner. Negative beliefs about exposure appear common among therapists and may pose a barrier to its dissemination. To permit reliable and valid assessment of such beliefs, we constructed the 21-item Therapist Beliefs about Exposure Scale (TBES) and examined its reliability and validity in three samples of practicing clinicians. The TBES demonstrated a clear single-factor structure, excellent internal consistency (αs=.90-.96), and exceptionally high six-month test-retest reliability (r=.89). Negative beliefs about exposure therapy were associated with therapist demographic characteristics, negative reactions to a series of exposure therapy case vignettes, and the cautious delivery of exposure therapy in the treatment of a hypothetical client with obsessive-compulsive disorder. Lastly, TBES scores decreased markedly following a didactic workshop on exposure therapy. The present findings support the reliability and validity of the TBES.

  20. 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

  1. 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...

  2. 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...

  3. 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...

  4. 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…

  5. 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. ...

  6. 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...

  7. 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...

  8. 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...

  9. Profiling postgraduate workplace-based assessment implementation in Ireland: a retrospective cohort study.

    PubMed

    Barrett, Aileen; Galvin, Rose; Steinert, Yvonne; Scherpbier, Albert; O'Shaughnessy, Ann; Walsh, Gillian; Horgan, Mary

    2016-01-01

    In 2010, workplace-based assessment (WBA) was formally integrated as a method of formative trainee assessment into 29 basic and higher specialist medical training (BST/HST) programmes in six postgraduate training bodies in Ireland. The aim of this study is to explore how WBA is being implemented and to examine if WBA is being used formatively as originally intended. A retrospective cohort study was conducted and approved by the institution's Research Ethics Committee. A profile of WBA requirements was obtained from 29 training programme curricula. A data extraction tool was developed to extract anonymous data, including written feedback and timing of assessments, from Year 1 and 2 trainee ePortfolios in 2012-2013. Data were independently quality assessed and compared to the reference standard number of assessments mandated annually where relevant. All 29 training programmes mandated the inclusion of at least one case-based discussion (max = 5; range 1-5). All except two non-clinical programmes (93 %) required at least two mini-Clinical Evaluation Exercise assessments per year and Direct Observation of Procedural Skills assessments were mandated in 27 training programmes over the course of the programme. WBA data were extracted from 50 % of randomly selected BST ePortfolios in four programmes (n = 142) and 70 % of HST ePortfolios (n = 115) in 21 programmes registered for 2012-2013. Four programmes did not have an eligible trainee for that academic year. In total, 1142 WBAs were analysed. A total of 164 trainees (63.8 %) had completed at least one WBA. The average number of WBAs completed by HST trainees was 7.75 (SD 5.8; 95 % CI 6.5-8.9; range 1-34). BST trainees completed an average of 6.1 assessments (SD 9.3; 95 % CI 4.01-8.19; range 1-76). Feedback-of varied length and quality-was provided on 44.9 % of assessments. The majority of WBAs were completed in the second half of the year. There is significant heterogeneity with respect to the frequency and

  10. Semi-quantitative exposure assessment of occupational exposure to wood dust and nasopharyngeal cancer risk.

    PubMed

    Ekpanyaskul, Chatchai; Sangrajrang, Suleeporn; Ekburanawat, Wiwat; Brennan, Paul; Mannetje, Andrea; Thetkathuek, Anamai; Saejiw, Nutjaree; Ruangsuwan, Tassanu; Boffetta, Paolo

    2015-01-01

    Occupational exposure to wood dust is one cause of nasopharyngeal cancer (NPC); however, assessing this exposure remains problematic. Therefore, the objective of this study was to develop a semi-quantitative exposure assessment method and then utilize it to evaluate the association between occupational exposure to wood dust and the development of NPC. In addition, variations in risk by histology were examined. A case-control study was conducted with 327 newly diagnosed cases of NPC at the National Cancer Institute and regional cancer centers in Thailand with 1:1 controls matched for age, gender and geographical residence. Occupational information was obtained through personal interviews. The potential probability, frequency and intensity of exposure to wood dust were assessed on a job-by-job basis by experienced experts. Analysis was performed by conditional logistic regression and presented in odds ratio (ORs) estimates and 95% confidence intervals (CI). Overall, a non significant relationship between occupational wood dust exposure and NPC risk for all subjects was observed (ORs=1.61, 95%CI 0.99-2.59); however, the risk became significant when analyses focused on types 2 and 3 of NPC (ORs=1.62, 95%CI 1.03-2.74). The significant association was stronger for those exposed to wood dust for >10 year (ORs=2.26, 95%CI 1.10-4.63), for those with first-time exposure at age>25 year (ORs=2.07, 95%CI 1.08-3.94), and for those who had a high cumulative exposure (ORs=2.17, 95%CI 1.03-4.58) when compared with those considered unexposed. In conclusion, wood dust is likely to be associated with an increased risk of type 2 or 3 NPC in the Thai population. The results of this study show that semi-quantitative exposure assessment is suitable for occupational exposure assessment in a case control study and complements the information from self-reporting.

  11. 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.

  12. Exposure and control assessment of semiconductor manufacturing

    NASA Astrophysics Data System (ADS)

    Jones, James H.

    1988-07-01

    From 1980 to 1984, the National Institute for Occupational Safety and Health (NIOSH), along with the U.S. Environmental Protection Agency (EPA), sponsored a study of worker exposures and controls in semiconductor manufacturing. The study was conducted by Battelle Columbus Laboratories and PEDCO Environmental. Walk-through surveys were conducted at 21 plants and in-depth studies were done at four of these plants. Processes studied included photolithography, chemical vapor deposition, wet chemical etching and cleaning, plasma etching, diffusion, ion implantation, and metallization. Air samples were collected for acetone, antimony, arsenic, boron, n-butyl acetate, diborane, 2-ethoxyethyl acetate, hexamethyldisilizane, hydrogen chloride, hydrogen fluoride, 2-methoxyethanol, methyl ethyl ketone, nitric acid, phosphorus, sulfuric acid, and xylene. In addition, radio-frequency and ionizing radiation were monitored and ventilation measured. In general, results were well below recommended standards for routine operations. One exception was radio-frequency radiation where there was the potential for overexposure in several instances. Worker exposures during maintenance operations and process upset conditions were not able to be evaluated.

  13. Exposure assessment at 30 000 feet: challenges and future directions.

    PubMed

    Grajewski, Barbara; Pinkerton, Lynne E

    2013-07-01

    Few studies of cancer mortality and incidence among flight crew have included a detailed assessment of both occupational exposures and lifestyle factors that may influence the risk of cancer. In this issue, Kojo et al. (Risk factors for skin cancer among Finnish airline cabin crew. Ann Occup. Hyg 2013; 57: 695-704) evaluated the relative contributions of ultraviolet and cosmic radiation to the incidence of skin cancer in Finnish flight attendants. This is a useful contribution, yet the reason flight crew members have an increased risk of skin cancer compared with the general population remains unclear. Good policy decisions for flight crew will depend on continued and emerging effective collaborations to increase study power and improve exposure assessment in future flight crew health studies. Improving the assessment of occupational exposures and non-occupational factors will cost additional time and effort, which are well spent if the role of exposures can be clarified in larger studies. PMID:23818455

  14. Exposure Assessment at 30 000 Feet: Challenges and Future Directions

    PubMed Central

    Grajewski, Barbara; Pinkerton, Lynne E.

    2015-01-01

    Few studies of cancer mortality and incidence among flight crew have included a detailed assessment of both occupational exposures and lifestyle factors that may influence the risk of cancer. In this issue, Kojo et al. (Risk factors for skin cancer among Finnish airline cabin crew. Ann. Occup. Hyg 2013; 57: 695–704) evaluated the relative contributions of ultraviolet and cosmic radiation to the incidence of skin cancer in Finnish flight attendants. This is a useful contribution, yet the reason flight crew members have an increased risk of skin cancer compared with the general population remains unclear. Good policy decisions for flight crew will depend on continued and emerging effective collaborations to increase study power and improve exposure assessment in future flight crew health studies. Improving the assessment of occupational exposures and non-occupational factors will cost additional time and effort, which are well spent if the role of exposures can be clarified in larger studies. PMID:23818455

  15. Exposure assessment: Serum levels of TCDD in Seveso, Italy

    SciTech Connect

    Needham, L.L.; Patterson, D.G. Jr.; Smith, S.J.; Sampson, E.J.; Gerthoux, P.M.; Brambilla, P.; Mocarelli, P.

    1999-02-01

    Accurate exposure assessment is an important step in both risk assessment and epidemiologic studies involving potential human exposure to environmental toxicants. Various methods have been used to assess human exposure. These methods include models based on one`s temporal and spatial nearness to the source, environmental levels of toxicant, and biological measures. The authors believe that the latter measure is the ``gold standard.`` In this article they present the serum 2,3,7,8-tetrachlorodibenzo-p-dioxin levels in residents of the contaminated zones in Seveso, Italy, in 1976, and delineate these data by age and gender. Some of these serum levels are among the highest ever reported and thus this population serves as a benchmark for comparison of human exposure and potential adverse health effects. One such potential population is that population consuming potentially contaminated fish.

  16. 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

  17. 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

  18. Post-traumatic amnesia and confusional state: hazards of retrospective assessment.

    PubMed

    Friedland, Daniel; Swash, Michael

    2016-10-01

    Retrospective assessment of post-traumatic amnesia (PTA) must take into account factors other than traumatic brain injury (TBI) which may impact on memory both at the time of injury and subsequent to the injury. These include analgesics, anaesthesia required for surgery, and the development of acute or post-traumatic stress disorder. This is relevant in clinical and medicolegal settings. Repeated assessments of the post-injury state, involving tests for continuing amnesia, risk promoting recall of events suggested by the examiner, or generating confabulations. The PTA syndrome affects the categorical autobiographical memory, and is accompanied by confusion as an essential component; this should be suspected from the initial or early Glasgow Coma Scale score (13-14/15) if not directly recorded by clinical staff. PTA by itself is only one of several indices of severity of TBI. The nature of the head injury, including observers' accounts, clinical and neuroimaging data, the possible role of other external injuries, blood loss, acute stress disorder and the potential for hypoxic brain injury, must be taken into account as well as concomitant alcohol or substance abuse, and systemic shock. A plausible mechanism for a TBI must be demonstrable, and other causes of amnesia excluded.

  19. Post-traumatic amnesia and confusional state: hazards of retrospective assessment.

    PubMed

    Friedland, Daniel; Swash, Michael

    2016-10-01

    Retrospective assessment of post-traumatic amnesia (PTA) must take into account factors other than traumatic brain injury (TBI) which may impact on memory both at the time of injury and subsequent to the injury. These include analgesics, anaesthesia required for surgery, and the development of acute or post-traumatic stress disorder. This is relevant in clinical and medicolegal settings. Repeated assessments of the post-injury state, involving tests for continuing amnesia, risk promoting recall of events suggested by the examiner, or generating confabulations. The PTA syndrome affects the categorical autobiographical memory, and is accompanied by confusion as an essential component; this should be suspected from the initial or early Glasgow Coma Scale score (13-14/15) if not directly recorded by clinical staff. PTA by itself is only one of several indices of severity of TBI. The nature of the head injury, including observers' accounts, clinical and neuroimaging data, the possible role of other external injuries, blood loss, acute stress disorder and the potential for hypoxic brain injury, must be taken into account as well as concomitant alcohol or substance abuse, and systemic shock. A plausible mechanism for a TBI must be demonstrable, and other causes of amnesia excluded. PMID:26888959

  20. 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.

  1. 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...

  2. Assessing human exposure to airborne pollutants: Advances and opportunities

    SciTech Connect

    Lioy, P.J. )

    1991-08-01

    A committee which was convened by the National Research Council, recently completed an analysis of new methods and technologies for assessing exposure to air pollutants. The committee identified three major ways of determining human exposure to airborne pollutants. Monitoring the air around an individual with a portable personal air sampler is, of course, the most comprehensive and most accurate. It is also the costliest and most time consuming. The second method is more indirect and involves techniques such as measuring the amount of a contaminant with a stationary monitor and extrapolating exposure by means of personal activity records or mathematical models. Exposure to carbon monoxide inside a car, for example, might be roughly calculated from the amount of time spent in the car and the quantity of carbon monoxide in the car under typical operating conditions. The third method involves biological markers as a measure of the integrated dose within the body and of past contact with pollutants. For example, a marker for airborne lead exposure can be elevated lead levels in the blood. However, this must be weighed against contributions from other media. A final and major point made in the report is the need to have accurate and realistic assessments to ensure optimal reduction of human exposure. To accomplish this, exposure assessment research should be supported by government programs. Although not stated, such research should also be supported by other sectors, including the regulated community.

  3. Parental Retrospective Assessment of Development and Behavior in Asperger Syndrome during the First 2 Years of Life

    ERIC Educational Resources Information Center

    Dewrang, Petra; Sandberg, Annika Dahlgren

    2010-01-01

    Development and behavior during the first 2 years of life was assessed retrospectively by the parents to 23 adolescents and young adults with Asperger syndrome and 13 typically developing adolescents and young adults. The groups were matched on chronological age and the participants were within the normal range of intelligence. The questionnaire,…

  4. Biomonitoring as a method for assessing exposure to perchlorate.

    PubMed

    Blount, Benjamin C; Valentín-Blasini, Liza

    2007-09-01

    Biomonitoring provides direct and quantitative information regarding human exposure to environmental toxicants, such as perchlorate (ClO(4)(-)). Because of concerns surrounding widespread exposure to ClO(4)(-), we are using biomonitoring methods to assess exposure to ClO(4)(-) and other physiologically relevant anions that can impact iodide uptake by the thyroid. These methods quantify ClO(4)(-), thiocyanate, nitrate, and iodide in human urine, milk, serum, blood spots, amniotic fluid, and infant formula using ion chromatography coupled with electrospray ionization tandem mass spectrometry. In this paper we summarize recent ClO(4)(-) biomonitoring research and provide three additional examples of the utility of biomonitoring for characterizing ClO(4)(-) exposure. Specifically, we examine variability in ClO(4)(-) excretion, compare the relative importance of different exposure sources in adults, and estimate ClO(4)(-) exposure in formula-fed infants. These applications provide examples of how biomonitoring can improve individual exposure assessment. Individual biomarker data can subsequently be compared with individual thyroid function data to better evaluate potential linkage between ClO(4)(-) exposure and health. PMID:17822374

  5. 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

  6. 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.

  7. 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. PMID:26173853

  8. Tools for regulatory assessment of occupational exposure: development and challenges.

    PubMed

    Tielemans, Erik; Warren, Nick; Schneider, Thomas; Tischer, Martin; Ritchie, Peter; Goede, Henk; Kromhout, Hans; Van Hemmen, Joop; Cherrie, John W

    2007-12-01

    REACH (Registration, Evaluation and Authorization of CHemicals) requires improved exposure models that can be incorporated into screening tools and refined assessment tools. These are referred to as tier 1 and 2 models, respectively. There are a number of candidate in tier 1 models that could be used with REACH. Tier 2 models, producing robust and realistic exposure assessments, are currently not available. A research programme is proposed in this paper that will result in a new, advanced exposure assessment tool for REACH. In addition, issues related to variability and uncertainty are discussed briefly, and some examples of tier 1 screening tools are presented. The proposed framework for the tier 2 tool is based on a Bayesian approach, and makes full use of mechanistically modelled estimates and any relevant measurements of exposure. The new approach will preclude the necessity to conduct of case-by-case exposure measurements for each chemical and scenario, since the system will allow for the use of analogous exposure data from relatively comparable scenarios. The development of the new approach requires substantial effort in the area of mechanistic modelling, database development and Bayesian statistical techniques. In this paper, the data gaps and areas for future research are identified to help realise and further improve this type of approach within REACH. A structured data collection and storage system is a central element of the research programme and the availability of this type of tool may also facilitate the sharing of exposure data down and up the supply chain. In addition, new data that are stored according to the proposed structure could enable the validation of any exposure model and thus this programme enhances the exposure assessment field as a whole.

  9. Developing an Ethical and Legal Interoperability Assessment Process for Retrospective Studies.

    PubMed

    Tassé, Anne-Marie; Kirby, Emily; Fortier, Isabel

    2016-06-01

    The past decade has witnessed the creation of major international research consortia, aiming to facilitate the sharing of data from different studies to maximize health benefits. However, combining heterogeneous data across existing studies requires addressing issues related to both data harmonization and ethical and legal interoperability. This article proposes a rigorous interoperability assessment process to assess whether different data sets are sufficiently ethically and legally interoperable to allow for a given proposed research use. The methodology used to develop this process is based on a comprehensive analysis of the international ethical and legal framework governing the use of retrospective data in research, and includes the following steps: (I) finding existing processes; (II) comparing processes to identify similarities and differences and determining the limits of the "consistent whole"; (III) establishing common principles and procedures; and, (IV) changing or removing processes that do not contribute to the consistent whole. Each of these four steps were examined using step-specific methodologies, including (a) literature and policy reviews; (b) consultations with international ethical, legal and social implications (ELSI) experts; and (c) a case study piloting the proposed framework in an actual international research consortium. This assessment process takes into account key legal and ethical components such as consent, recontact, and waiver of consent. As a result, this analysis allows the development of a comprehensive filter used to verify the legal and ethical restrictions pertaining to a data set. This in turns helps in determining whether the given data set can to be used for a proposed research project, or is ethically and legally interoperable for use in research collaborations. By integrating this filter to the regular data access processes used by cohorts, not only will researchers be able to create virtual "mega-cohorts" of research

  10. Hypertension and Exposure to Noise near Airports (HYENA): study design and noise exposure assessment.

    PubMed

    Jarup, Lars; Dudley, Marie-Louise; Babisch, Wolfgang; Houthuijs, Danny; Swart, Wim; Pershagen, Göran; Bluhm, Gösta; Katsouyanni, Klea; Velonakis, Manolis; Cadum, Ennio; Vigna-Taglianti, Federica

    2005-11-01

    An increasing number of people live near airports with considerable noise and air pollution. The Hypertension and Exposure to Noise near Airports (HYENA) project aims to assess the impact of airport-related noise exposure on blood pressure (BP) and cardiovascular disease using a cross-sectional study design. We selected 6,000 persons (45-70 years of age) who had lived at least 5 years near one of six major European airports. We used modeled aircraft noise contours, aiming to maximize exposure contrast. Automated BP instruments are used to reduce observer error. We designed a standardized questionnaire to collect data on annoyance, noise disturbance, and major confounders. Cortisol in saliva was collected in a subsample of the study population (n = 500) stratified by noise exposure level. To investigate short-term noise effects on BP and possible effects on nighttime BP dipping, we measured 24-hr BP and assessed continuous night noise in another subsample (n = 200). To ensure comparability between countries, we used common noise models to assess individual noise exposure, with a resolution of 1 dB(A). Modifiers of individual exposure, such as the orientation of living and bedroom toward roads, window-opening habits, and sound insulation, were assessed by the questionnaire. For four airports, we estimated exposure to air pollution to explore modifying effects of air pollution on cardiovascular disease. The project assesses exposure to traffic-related air pollutants, primarily using data from another project funded by the European Union (APMoSPHERE, Air Pollution Modelling for Support to Policy on Health and Environmental Risks in Europe). PMID:16263498

  11. Explaining Differences between Retrospective and Traditional Pretest Self-Assessments: Competing Theories and Empirical Evidence

    ERIC Educational Resources Information Center

    Nimon, Kim

    2014-01-01

    Summarizing theory and results of empirical research, this article serves to illustrate why effects measured with retrospective pretests may be subject to bias and may not always be explained by response shift theory. It presents three contending theories to explain the difference between retrospective and traditional pretest results and considers…

  12. A Conceptual Framework for the Assessment of Cumulative Exposure to Air Pollution at a Fine Spatial Scale

    PubMed Central

    Wahida, Kihal-Talantikite; Padilla, Cindy M.; Denis, Zmirou-Navier; Olivier, Blanchard; Géraldine, Le Nir; Philippe, Quenel; Séverine, Deguen

    2016-01-01

    Many epidemiological studies examining long-term health effects of exposure to air pollutants have characterized exposure by the outdoor air concentrations at sites that may be distant to subjects’ residences at different points in time. The temporal and spatial mobility of subjects and the spatial scale of exposure assessment could thus lead to misclassification in the cumulative exposure estimation. This paper attempts to fill the gap regarding cumulative exposure assessment to air pollution at a fine spatial scale in epidemiological studies investigating long-term health effects. We propose a conceptual framework showing how major difficulties in cumulative long-term exposure assessment could be surmounted. We then illustrate this conceptual model on the case of exposure to NO2 following two steps: (i) retrospective reconstitution of NO2 concentrations at a fine spatial scale; and (ii) a novel approach to assigning the time-relevant exposure estimates at the census block level, using all available data on residential mobility throughout a 10- to 20-year period prior to that for which the health events are to be detected. Our conceptual framework is both flexible and convenient for the needs of different epidemiological study designs. PMID:26999170

  13. 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. PMID:26444190

  14. 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.

  15. Predicting biological effects of environmental mixtures using exposure:activity ratios (EAR) derived from US EPA’s ToxCast data: Retrospective application to chemical monitoring data

    EPA Science Inventory

    Chemical monitoring has been widely used in environmental surveillance to assess exposure to environmental contaminants which could represent potential hazards to exposed organisms. However, the ability to detect chemicals in the environment has rapidly outpaced assessment of pot...

  16. Lifetime history of indoor tanning in young people: a retrospective assessment of initiation, persistence, and correlates

    PubMed Central

    2012-01-01

    Background Despite educational and public health campaigns to convey the risks of indoor tanning, many individuals around the world continue to engage in this behavior. Few descriptive studies of indoor tanning have collected information pertaining to the lifetime history of indoor tanning, thereby limiting our ability to understand indoor tanning patterns and potentially target interventions for individuals who not only initiate, but continue to persistently engage in indoor tanning. Methods In-person interviews elicited detailed retrospective information on lifetime history of indoor tanning among white individuals (n = 401) under age 40 seen by a dermatologist for a minor benign skin condition. These individuals were controls in a case-control study of early-onset basal cell carcinoma. Outcomes of interest included ever indoor tanning in both males and females, as well as persistent indoor tanning in females - defined as females over age 31 who tanned indoors at least once in the last three or all four of four specified age periods (ages 11-15, 16-20, 21-30 and 31 or older). Multivariate logistic regression was used to identify sociodemographic and lifestyle correlates of ever and persistent indoor tanning in females. Results Approximately three-quarters (73.3%) of females and 38.3% of males ever tanned indoors, with a median age of initiation of 17.0 and 21.5, respectively. Among indoor tanners, 39.3% of females and 21.7% of males reported being burned while indoor tanning. Female ever indoor tanners were younger, had darker color eyes, and sunbathed more frequently than females who never tanned indoors. Using unique lifetime exposure data, 24.7% of female indoor tanners 31 and older persistently tanned indoors starting as teenagers. Female persistent indoor tanners drank significantly more alcohol, were less educated, had skin that tanned with prolonged sun exposure, and sunbathed outdoors more frequently than non-persistent tanners. Conclusions Indoor tanning

  17. 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.

  18. The ‘Maltreatment and Abuse Chronology of Exposure’ (MACE) Scale for the Retrospective Assessment of Abuse and Neglect During Development

    PubMed Central

    Teicher, Martin H.; Parigger, Angelika

    2015-01-01

    There is increasing interest in childhood maltreatment as a potent stimulus that may alter trajectories of brain development, induce epigenetic modifications and enhance risk for medical and psychiatric disorders. Although a number of useful scales exist for retrospective assessment of abuse and neglect they have significant limitations. Moreover, they fail to provide detailed information on timing of exposure, which is critical for delineation of sensitive periods. The Maltreatment and Abuse Chronology of Exposure (MACE) scale was developed in a sample of 1051 participants using item response theory to gauge severity of exposure to ten types of maltreatment (emotional neglect, non-verbal emotional abuse, parental physical maltreatment, parental verbal abuse, peer emotional abuse, peer physical bullying, physical neglect, sexual abuse, witnessing interparental violence and witnessing violence to siblings) during each year of childhood. Items included in the subscales had acceptable psychometric properties based on infit and outfit mean square statistics, and each subscale passed Andersen’s Likelihood ratio test. The MACE provides an overall severity score and multiplicity score (number of types of maltreatment experienced) with excellent test-retest reliability. Each type of maltreatment showed good reliability as did severity of exposure across each year of childhood. MACE Severity correlated 0.738 with Childhood Trauma Questionnaire (CTQ) score and MACE Multiplicity correlated 0.698 with the Adverse Childhood Experiences scale (ACE). However, MACE accounted for 2.00- and 2.07-fold more of the variance, on average, in psychiatric symptom ratings than CTQ or ACE, respectively, based on variance decomposition. Different types of maltreatment had distinct and often unique developmental patterns. The 52-item MACE, a simpler Maltreatment Abuse and Exposure Scale (MAES) that only assesses overall exposure and the original test instrument (MACE-X) with several

  19. Mercury from dental amalgam: exposure and risk assessment.

    PubMed

    Koral, Stephen M

    2013-02-01

    There has long been an undercurrent within the dental profession of anti-amalgam sentiment, a "mercury-free" movement. To assess whether anything is or is not scientifically wrong with amalgam, one must look to the vast literature on exposure, toxicology, and risk assessment of mercury. The subject of risk assessment goes straight to the heart of the debate over whether a malgam is safe, or not, for unrestricted use in dentistry in the population at large.

  20. 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.

  1. 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. PMID:25455887

  2. Advances in pesticide environmental fate and exposure assessments.

    PubMed

    Rice, Pamela J; Rice, Patricia J; Arthur, Ellen L; Barefoot, Aldos C

    2007-07-11

    Globalization of markets and the growing world population increase threats of invasive and exotic species and place greater demands on food and fiber production. Pest management in both agricultural and nonagricultural settings employs established practices and new biological, chemical, and management technologies. Pesticides are an essential tool in integrated pest management. Without pesticides a significant percentage of food and fiber crops would be lost, infectious diseases would increase, and valuable native habitats would be devastated. Therefore, it is important to understand the environmental fate of pesticides and assess their potential exposure and associated risks to human health and the environment. This paper summarizes the Advances in Pesticide Environmental Fate and Exposure Assessment symposium held at the 231st National Meeting of the American Chemical Society (Atlanta, GA, 2006). The focus of the symposium was to provide current information on advances in pesticide environmental fate and exposure assessments. Thirty papers were presented on advances ranging from subcellular processes to watershed-scale studies on topics including chemical degradation, sorption, and transport; improved methodologies; use of modeling and predictive tools; exposure assessment; and treatment and remediation. This information is necessary to develop more effective pesticide use and management practices, to better understand pesticide fate and associated exposures and risks, to develop mitigation and remediation strategies, and to establish sound science-based regulations.

  3. 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.

  4. Radiation exposure assessment for portsmouth naval shipyard health studies.

    PubMed

    Daniels, R D; Taulbee, T D; Chen, P

    2004-01-01

    Occupational radiation exposures of 13,475 civilian nuclear shipyard workers were investigated as part of a retrospective mortality study. Estimates of annual, cumulative and collective doses were tabulated for future dose-response analysis. Record sets were assembled and amended through range checks, examination of distributions and inspection. Methods were developed to adjust for administrative overestimates and dose from previous employment. Uncertainties from doses below the recording threshold were estimated. Low-dose protracted radiation exposures from submarine overhaul and repair predominated. Cumulative doses are best approximated by a hybrid log-normal distribution with arithmetic mean and median values of 20.59 and 3.24 mSv, respectively. The distribution is highly skewed with more than half the workers having cumulative doses <10 mSv and >95% having doses <100 mSv. The maximum cumulative dose is estimated at 649.39 mSv from 15 person-years of exposure. The collective dose was 277.42 person-Sv with 96.8% attributed to employment at Portsmouth Naval Shipyard. PMID:15266069

  5. Exposure assessment for power frequency electric and magnetic fields.

    PubMed

    Bracken, T D

    1993-04-01

    Over the past decade considerable data have been collected on electric and magnetic fields in occupational environments. These data have taken the form of area measurements, source characterizations, and personal exposure measurements. Occupational EMF levels are highly variable in space and time. Exposures associated with these fields exhibit similar large variations during a day, between days, and between individuals within a group. The distribution of exposure measures is skewed over several decades with only a few values occurring at the maximum field levels. The skewness of exposure measures implies that large sample sizes may be required for assessments and that multiple statistical descriptors are preferred to describe individual and group exposures. Except for the relatively few occupational settings where high voltage sources are prevalent, electric fields encountered in the workplace are probably similar to residential exposures. Consequently, high electric field exposures are essentially limited to utility environments and occupations. Within the electric utility industry, it is definitely possible to identify occupations with high electric field exposures relative to those of office workers or other groups. The highly exposed utility occupations are linemen, substation operators, and utility electricians. The distribution of electric field exposures in the utility worker population is very skewed even within a given occupation. As with electric fields, magnetic fields in the workplace appear to be comparable with residential levels, unless a clearly defined high-current source is present. Since high-current sources are more prevalent than high-voltage sources, environments with relatively high magnetic field exposures encompass a more diverse set of occupations than do those with high electric fields. Within the electric utility industry, it is possible to identify occupational environments with high magnetic field exposure relative to the office

  6. 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 ...

  7. Assessing recall in mothers' retrospective reports: concerns over children's speech and language development.

    PubMed

    Russell, Ginny; Miller, Laura L; Ford, Tamsin; Golding, Jean

    2014-01-01

    Retrospective recall about children's symptoms is used to establish early developmental patterns in clinical practice and is also utilised in child psychopathology research. Some studies have indicated that the accuracy of retrospective recall is influenced by life events. Our hypothesis was that an intervention: speech and language therapy, would adversely affect the accuracy of parent recall of early concerns about their child's speech and language development. Mothers (n = 5,390) reported on their child's speech development (child male to female ratio = 50:50) when their children were aged 18 or 30 months, and also reported on these early concerns retrospectively, 10 years later, when their children were 13 years old. Overall reliability of retrospective recall was good, 86 % of respondents accurately recalling their earlier concerns. As hypothesised, however, the speech and language intervention was strongly associated with inaccurate retrospective recall about concerns in the early years (Relative Risk Ratio = 19.03; 95 % CI:14.78-24.48). Attendance at speech therapy was associated with increased recall of concerns that were not reported at the time. The study suggests caution is required when interpreting retrospective reports of abnormal child development as recall may be influenced by intervening events.

  8. Opportunities for using spatial property assessment data in air pollution exposure assessments

    PubMed Central

    Setton, Eleanor M; Hystad, Perry W; Keller, C Peter

    2005-01-01

    Background Many epidemiological studies examining the relationships between adverse health outcomes and exposure to air pollutants use ambient air pollution measurements as a proxy for personal exposure levels. When pollution levels vary at neighbourhood levels, using ambient pollution data from sparsely located fixed monitors may inadequately capture the spatial variation in ambient pollution. A major constraint to moving toward exposure assessments and epidemiological studies of air pollution at a neighbourhood level is the lack of readily available data at appropriate spatial resolutions. Spatial property assessment data are widely available in North America and may provide an opportunity for developing neighbourhood level air pollution exposure assessments. Results This paper provides a detailed description of spatial property assessment data available in the Pacific Northwest of Canada and the United States, and provides examples of potential applications of spatial property assessment data for improving air pollution exposure assessment at the neighbourhood scale, including: (1) creating variables for use in land use regression modelling of neighbourhood levels of ambient air pollution; (2) enhancing wood smoke exposure estimates by mapping fireplace locations; and (3) using data available on individual building characteristics to produce a regional air pollution infiltration model. Conclusion Spatial property assessment data are an extremely detailed data source at a fine spatial resolution, and therefore a source of information that could improve the quality and spatial resolution of current air pollution exposure assessments. PMID:16262893

  9. 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. PMID:16393801

  10. 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

  11. Perinatal Immunotoxicity: Why Adult Exposure Assessment Fails to Predict Risk

    PubMed Central

    Dietert, Rodney R.; Piepenbrink, Michael S.

    2006-01-01

    Recent research has pointed to the developing immune system as a remarkably sensitive toxicologic target for environmental chemicals and drugs. In fact, the perinatal period before and just after birth is replete with dynamic immune changes, many of which do not occur in adults. These include not only the basic maturation and distribution of immune cell types and selection against autoreactive lymphocytes but also changes designed specifically to protect the pregnancy against immune-mediated miscarriage. The newborn is then faced with critical immune maturational adjustments to achieve an immune balance necessary to combat myriad childhood and later-life diseases. All these processes set the fetus and neonate completely apart from the adult regarding immunotoxicologic risk. Yet for decades, safety evaluation has relied almost exclusively upon exposure of the adult immune system to predict perinatal immune risk. Recent workshops and forums have suggested a benefit in employing alternative exposures that include exposure throughout early life stages. However, issues remain concerning when and where such applications might be required. In this review we discuss the reasons why immunotoxic assessment is important for current childhood diseases and why adult exposure assessment cannot predict the effect of xenobiotics on the developing immune system. It also provides examples of developmental immunotoxicants where age-based risk appears to differ. Finally, it stresses the need to replace adult exposure assessment for immune evaluation with protocols that can protect the developing immune system. PMID:16581533

  12. 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.

  13. 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.

  14. European consumer exposure to cosmetic products, a framework for conducting population exposure assessments.

    PubMed

    Hall, B; Tozer, S; Safford, B; Coroama, M; Steiling, W; Leneveu-Duchemin, M C; McNamara, C; Gibney, M

    2007-11-01

    Access to reliable exposure data is essential to evaluate the toxicological safety of ingredients in cosmetic products. This study was carried out by European cosmetic manufacturers acting within the trade association Colipa, with the aim to construct a probabilistic European population model of exposure. The study updates, in distribution form, the current exposure data on daily quantities of six cosmetic products. Data were collected using a combination of market information databases and a controlled product use study. In total 44,100 households and 18,057 individual consumers in five European countries provided data using their own products. All product use occasions were recorded, including those outside of home. The raw data were analysed using Monte Carlo simulation and a European Statistical Population Model of exposure was constructed. A significant finding was an inverse correlation between frequency of product use and quantity used per application for body lotion, facial moisturiser, toothpaste and shampoo. Thus it is not appropriate to calculate daily exposure to these products by multiplying the maximum frequency value by the maximum quantity per event value. The results largely confirm the exposure parameters currently used by the cosmetic industry. Design of this study could serve as a model for future assessments of population exposure to chemicals in products other than cosmetics.

  15. Carbon nanotube dosimetry: from workplace exposure assessment to inhalation toxicology

    PubMed Central

    2013-01-01

    Background Dosimetry for toxicology studies involving carbon nanotubes (CNT) is challenging because of a lack of detailed occupational exposure assessments. Therefore, exposure assessment findings, measuring the mass concentration of elemental carbon from personal breathing zone (PBZ) samples, from 8 U.S.-based multi-walled CNT (MWCNT) manufacturers and users were extrapolated to results of an inhalation study in mice. Results Upon analysis, an inhalable elemental carbon mass concentration arithmetic mean of 10.6 μg/m3 (geometric mean 4.21 μg/m3) was found among workers exposed to MWCNT. The concentration equates to a deposited dose of approximately 4.07 μg/d in a human, equivalent to 2 ng/d in the mouse. For MWCNT inhalation, mice were exposed for 19 d with daily depositions of 1970 ng (equivalent to 1000 d of a human exposure; cumulative 76 yr), 197 ng (100 d; 7.6 yr), and 19.7 ng (10 d; 0.76 yr) and harvested at 0, 3, 28, and 84 d post-exposure to assess pulmonary toxicity. The high dose showed cytotoxicity and inflammation that persisted through 84 d after exposure. The middle dose had no polymorphonuclear cell influx with transient cytotoxicity. The low dose was associated with a low grade inflammatory response measured by changes in mRNA expression. Increased inflammatory proteins were present in the lavage fluid at the high and middle dose through 28 d post-exposure. Pathology, including epithelial hyperplasia and peribronchiolar inflammation, was only noted at the high dose. Conclusion These findings showed a limited pulmonary inflammatory potential of MWCNT at levels corresponding to the average inhalable elemental carbon concentrations observed in U.S.-based CNT facilities and estimates suggest considerable years of exposure are necessary for significant pathology to occur at that level. PMID:24144386

  16. 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...

  17. 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...

  18. 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...

  19. 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 ...

  20. 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...

  1. 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...

  2. 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

  3. 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...

  4. 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...

  5. 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...

  6. 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.

  7. Sulfur Oxides Risk and Exposure Assessment Planning Document

    EPA Science Inventory

    In conducting risk/exposure assessments for the Sulfur Oxides NAAQS review, EPA will first develop a draft Scope and Methods Plan which will describe the proposed scope of the quantitative and qualitative analyses to be performed and the tools/methods that may be employed

  8. Data analysis techniques: a tool for cumulative exposure assessment.

    PubMed

    Lalloué, Benoît; Monnez, Jean-Marie; Padilla, Cindy; Kihal, Wahida; Zmirou-Navier, Denis; Deguen, Séverine

    2015-01-01

    Everyone is subject to environmental exposures from various sources, with negative health impacts (air, water and soil contamination, noise, etc.or with positive effects (e.g. green space). Studies considering such complex environmental settings in a global manner are rare. We propose to use statistical factor and cluster analyses to create a composite exposure index with a data-driven approach, in view to assess the environmental burden experienced by populations. We illustrate this approach in a large French metropolitan area. The study was carried out in the Great Lyon area (France, 1.2 M inhabitants) at the census Block Group (BG) scale. We used as environmental indicators ambient air NO2 annual concentrations, noise levels and proximity to green spaces, to industrial plants, to polluted sites and to road traffic. They were synthesized using Multiple Factor Analysis (MFA), a data-driven technique without a priori modeling, followed by a Hierarchical Clustering to create BG classes. The first components of the MFA explained, respectively, 30, 14, 11 and 9% of the total variance. Clustering in five classes group: (1) a particular type of large BGs without population; (2) BGs of green residential areas, with less negative exposures than average; (3) BGs of residential areas near midtown; (4) BGs close to industries; and (5) midtown urban BGs, with higher negative exposures than average and less green spaces. Other numbers of classes were tested in order to assess a variety of clustering. We present an approach using statistical factor and cluster analyses techniques, which seem overlooked to assess cumulative exposure in complex environmental settings. Although it cannot be applied directly for risk or health effect assessment, the resulting index can help to identify hot spots of cumulative exposure, to prioritize urban policies or to compare the environmental burden across study areas in an epidemiological framework.

  9. Exposure assessment of particulate matter for susceptible populations in Seattle.

    PubMed Central

    Liu, L-J Sally; Box, Michael; Kalman, David; Kaufman, Joel; Koenig, Jane; Larson, Tim; Lumley, Thomas; Sheppard, Lianne; Wallace, Lance

    2003-01-01

    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 asthma. The average personal exposures to PM with aerodynamic diameters < 2.5 microm (PM2.5) were similar to the average outdoor PM2.5 concentrations but significantly higher than the average indoor concentrations. Personal PM2.5 exposures in our study groups were lower than those reported in other panel studies of susceptible populations. Indoor and outdoor PM2.5, PM10 (PM with aerodynamic diameters < 10 microm), and the ratio of PM2.5 to PM10 were significantly higher during the heating season. The increase in outdoor PM10 in winter was primarily due to an increase in the PM2.5 fraction. A similar seasonal variation was found for personal PM2.5. The high-risk subjects in our study engaged in an equal amount of dust-generating activities compared with the healthy elderly subjects. The children in the study experienced the highest indoor PM2.5 and PM10 concentrations. Personal PM2.5 exposures varied by study group, with elderly healthy and CHD subjects having the lowest exposures and asthmatic children having the highest exposures. Within study groups, the PM2.5 exposure varied depending on residence because of different particle infiltration efficiencies. Although we found a wide range of longitudinal correlations between central-site and personal PM2.5 measurements, the longitudinal r is closely related to the particle infiltration efficiency. PM2.5 exposures among the COPD and CHD subjects can be predicted with relatively good power with a microenvironmental model composed of three microenvironments. The prediction power is the lowest for the asthmatic children. PMID:12782491

  10. Assessment of human exposure level to PM10 in China

    NASA Astrophysics Data System (ADS)

    An, Xingqin; Hou, Qing; Li, Nan; Zhai, Shixian

    2013-05-01

    Epidemiological studies have found that atmospheric particulate matter, especially PM10 (inhalable particulate matter with aerodynamic diameter less than or equal to 10 μm) is one of the pollutants that are harmful to human health. In recent years, particulate matter pollution in China is becoming increasingly serious and PM10 has become the primary pollutant in Beijing and other cities. Therefore, it is necessary to carry out studies and a health damage assessment of PM10. In human health damage assessment, measuring human exposure level to PM10 is required and crucial to provide accurate exposure data for the exposure-response relationship, and also for the accurate quantitative assessment of human exposure. The spatial distribution of particle concentration in China is variable because of spatial differences in the local economic level and the geographical environment. Along with the accelerating urbanisation in China, city population density is high, and the population distribution is variable between and within cities, thus resulting in different population numbers exposed to different concentration ranges. Therefore, an accurate assessment of China's level of exposure to particulate matter is a priority and the basis for assessing the damage to public health caused by particle pollution. Using high accuracy population and PM10 monitoring data, this study analysed the human exposure to PM10 in different regions and typical cities of China. The results show that for most areas of China, the population-weighted PM10 exposure concentration is slightly higher than the annual mean concentration, meaning that more of the population is exposed to high concentrations, and most of the population is exposed to levels that meet the second national standard (between 40 and 100 μg m-3), occupying about 83.7% of population and 76.3% of area in China. The population exposure to PM10 is higher in two types of typical regions and cities: areas with dense human populations

  11. 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...

  12. 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.

  13. Environmental exposure assessment framework for nanoparticles in solid waste.

    PubMed

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

    2014-01-01

    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.

  14. [Risk assessment of human exposure to pesticides in food].

    PubMed

    Knežević, Zorka; Serdar, Maja

    2011-09-01

    This review presents methods for the assessment of acute and chronic risk from pesticide residues in food. Multiple pesticide residues can often be found in food. Currently, there is no internationally accepted procedure for the assessment of cumulative exposure to multiple pesticide residues in food. Therefore, risk assessment is based on toxicological evaluation of single compounds in a food matrix. The international estimation of short-term intake model (IESTI) has been used to calculate acute intake. IESTI is based on "the worst-case scenario" and addresses the possibility that consumers sometimes eat large amounts of a food item, and such a large amount might contain residues at highest levels. However, it should take into account uneven distribution of pesticide residues in food. Chronic exposure is based on a deterministic approach, analogous to the calculation of the theoretical maximum daily intake.

  15. 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.

  16. Assessing the reproductive health of men with occupational exposures.

    PubMed

    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.

  17. 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

  18. 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.

  19. 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).

  20. 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.

  1. 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.

  2. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study

    PubMed Central

    Pearce, Mark S; Salotti, Jane A; Little, Mark P; McHugh, Kieran; Lee, Choonsik; Kim, Kwang Pyo; Howe, Nicola L; Ronckers, Cecile M; Rajaraman, Preetha; Craft, Alan W; Parker, Louise; de González, Amy Berrington

    2012-01-01

    Summary Background Although CT scans are very useful clinically, potential cancer risks exist from associated ionising radiation, in particular for children who are more radiosensitive than adults. We aimed to assess the excess risk of leukaemia and brain tumours after CT scans in a cohort of children and young adults. Methods In our retrospective cohort study, we included patients without previous cancer diagnoses who were first examined with CT in National Health Service (NHS) centres in England, Wales, or Scotland (Great Britain) between 1985 and 2002, when they were younger than 22 years of age. We obtained data for cancer incidence, mortality, and loss to follow-up from the NHS Central Registry from Jan 1, 1985, to Dec 31, 2008. We estimated absorbed brain and red bone marrow doses per CT scan in mGy and assessed excess incidence of leukaemia and brain tumours cancer with Poisson relative risk models. To avoid inclusion of CT scans related to cancer diagnosis, follow-up for leukaemia began 2 years after the first CT and for brain tumours 5 years after the first CT. Findings During follow-up, 74 of 178 604 patients were diagnosed with leukaemia and 135 of 176 587 patients were diagnosed with brain tumours. We noted a positive association between radiation dose from CT scans and leukaemia (excess relative risk [ERR] per mGy 0·036, 95% CI 0·005–0·120; p=0·0097) and brain tumours (0·023, 0·010–0·049; p<0·0001). Compared with patients who received a dose of less than 5 mGy, the relative risk of leukaemia for patients who received a cumulative dose of at least 30 mGy (mean dose 51·13 mGy) was 3·18 (95% CI 1·46–6·94) and the relative risk of brain cancer for patients who received a cumulative dose of 50–74 mGy (mean dose 60·42 mGy) was 2·82 (1·33–6·03). Interpretation Use of CT scans in children to deliver cumulative doses of about 50 mGy might almost triple the risk of leukaemia and doses of about 60 mGy might triple the risk of brain

  3. 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. PMID:26330016

  4. 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.

  5. Assessing total exposures to gasoline vapor using the source exposure model.

    PubMed

    Edgerton, S A; Shah, J J

    1992-01-01

    Recent developments in source apportionment modeling of volatile organic compounds (VOCs) include receptor modeling (RM) applications to "total" (indoor and outdoor) exposure assessment for source of VOC. Source fingerprints are available for major VOC sources such as gasoline vapor, automobile exhaust, refinery emissions, cleaning solvent vapors, printing inks, and waste-water treatment facilities. The relative proportion of each VOC species in the source fingerprint enables the RM method, through a least squares analysis, to identify each source's presence and quantify its contribution to ambient air concentrations. Sampling periods and locations may be selected to represent microenvironmental exposures. Receptor modeling has direct applicability to determining the relative contribution of gasoline vapors to VOC exposures in the general population.

  6. Assessing total exposures to gasoline vapor using the source exposure model.

    PubMed

    Edgerton, S A; Shah, J J

    1992-01-01

    Recent developments in source apportionment modeling of volatile organic compounds (VOCs) include receptor modeling (RM) applications to "total" (indoor and outdoor) exposure assessment for source of VOC. Source fingerprints are available for major VOC sources such as gasoline vapor, automobile exhaust, refinery emissions, cleaning solvent vapors, printing inks, and waste-water treatment facilities. The relative proportion of each VOC species in the source fingerprint enables the RM method, through a least squares analysis, to identify each source's presence and quantify its contribution to ambient air concentrations. Sampling periods and locations may be selected to represent microenvironmental exposures. Receptor modeling has direct applicability to determining the relative contribution of gasoline vapors to VOC exposures in the general population. PMID:1504631

  7. Creation of a retrospective job-exposure matrix using surrogate measures of exposure for a cohort of US career firefighters from San Francisco, Chicago and Philadelphia

    PubMed Central

    Dahm, Matthew M; Bertke, Stephen; Allee, Steve; Daniels, Robert D

    2015-01-01

    Objectives To construct a cohort-specific job-exposure matrix (JEM) using surrogate metrics of exposure for a cancer study on career firefighters from the Chicago, Philadelphia and San Francisco Fire Departments. Methods Departmental work history records, along with data on historical annual fire-runs and hours, were collected from 1950 to 2009 and coded into separate databases. These data were used to create a JEM based on standardised job titles and fire apparatus assignments using several surrogate exposure metrics to estimate firefighters’ exposure to the combustion byproducts of fire. The metrics included duration of exposure (cumulative time with a standardised exposed job title and assignment), fire-runs (cumulative events of potential fire exposure) and time at fire (cumulative hours of potential fire exposure). Results The JEM consisted of 2298 unique job titles alongside 16 174 fire apparatus assignments from the three departments, which were collapsed into 15 standardised job titles and 15 standardised job assignments. Correlations were found between fire-runs and time at fires (Pearson coefficient=0.92), duration of exposure and time at fires (Pearson coefficient=0.85), and duration of exposure and fire-runs (Pearson coefficient=0.82). Total misclassification rates were found to be between 16–30% when using duration of employment as an exposure surrogate, which has been traditionally used in most epidemiological studies, compared with using the duration of exposure surrogate metric. Conclusions The constructed JEM successfully differentiated firefighters based on gradient levels of potential exposure to the combustion byproducts of fire using multiple surrogate exposure metrics. PMID:26163543

  8. Retrospective studies.

    PubMed

    Silveira, Patrícia Pelufo; Manfro, Gisele Gus

    2015-01-01

    Large retrospective, epidemiological studies accumulated in the late 1980s, providing increasing evidence to the deeply rooted thought that perinatal events could persistently affect the individual's functioning and health/disease patterns throughout the lifetime. Evidences of such associations can be found in the literature since the beginning of the twentieth century, but studies from Barker, Hales, and colleagues serve as an important hallmark. They proposed the "thrifty phenotype" hypothesis, stating that poor nutrition in fetal and early infant life is detrimental to the development and function of the individuals' organism, predisposing them to the later development of adult chronic diseases. At first used to explain the increased risk for type 2 diabetes in low birth weight individuals, the hypothesis was soon adapted to other systems, becoming one of the core assumptions of the Developmental Origins of Adult Health and Disease (DOHaD) model. The central nervous system is also vulnerable to the effects of environmental variation during fetal or neonatal life. Many researchers have explored the effects of perinatal programming on the human neurodevelopment, and some aspects of the brain structure and/or functioning (such as cognitive function, physiological reactivity to stress, and the risk for behavioral disorders or psychopathology) were shown to be modifiable by the exposure to certain adverse events early in life such as neonatal infections, exposure to gestational psychosocial stress, nutrition during gestation, exposure to drugs, or tobacco smoking during pregnancy. Until recently, most studies focused on birth weight as a strong surrogate of the intrauterine environment, investigating the effects of low birth weight (as a marker of suboptimal fetal environment) on a variety of neurodevelopmental outcomes. Despite the fact that literature reviews on this topic are as old as 1940, the more recent retrospective studies are summarized in this chapter.

  9. A retrospective study on acute health effects due to volcanic ash exposure during the eruption of Mount Etna (Sicily) in 2002

    PubMed Central

    2013-01-01

    Background Mount Etna, located in the eastern part of Sicily (Italy), is the highest and most active volcano in Europe. During the sustained eruption that occurred in October-November 2002 huge amounts of volcanic ash fell on a densely populated area south-east of Mount Etna in Catania province. The volcanic ash fall caused extensive damage to infrastructure utilities and distress in the exposed population. This retrospective study evaluates whether or not there was an association between ash fall and acute health effects in exposed local communities. Methods We collected the number and type of visits to the emergency department (ED) for diseases that could be related to volcanic ash exposure in public hospitals of the Province of Catania between October 20 and November 7, 2002. We compared the magnitude of differences in ED visits between the ash exposure period in 2002 and the same period of the previous year 2001. Results We observed a significant increase of ED visits for acute respiratory and cardiovascular diseases, and ocular disturbances during the ash exposure time period. Conclusions There was a positive association between exposure to volcanic ash from the 2002 eruption of Mount Etna and acute health effects in the Catania residents. This study documents the need for public health preparedness and response initiatives to protect nearby populations from exposure to ash fall from future eruptions of Mount Etna. PMID:23924394

  10. Contribution of locally grown foods in cumulative exposure assessments.

    PubMed

    Lobscheid, Agnes B; Maddalena, Randy L; McKone, Thomas E

    2004-01-01

    Both laboratory and field studies confirm the importance of vegetation for scavenging semivolatile organic chemicals (SVOCs) from the atmosphere and a number of exposure studies have found that the dietary pathway is often a significant contributor to cumulative exposure for these chemicals. However, little information exists on the atmospheric source-to-dietary intake linkage for SVOCs. Because of higher SVOC emissions to urban regions, this linkage is particularly important for foods that are grown, distributed and consumed in or near urban regions. The food pathway can also contribute to dietary exposure for populations that are remote from a pollutant source if the pollutants can migrate to agricultural regions and subsequently to the agricultural commodities distributed to that population. We use available data, the characteristic travel distance, and the CalTOX multimedia model framework to assess the contribution of local sources of food to cumulative SVOC intake. Based on published concentration data for foods, our exposure calculations indicate that the potential intake through ingestion can be up to 1000 times that of inhalation for certain persistent SVOCs. We use the population-based intake fraction (iF) to determine how SVOC intake can vary among food commodities and exposure pathways, and to determine the contribution of airborne emitted SVOCs to the diet in the Northern Hemisphere. We focus on three representative multimedia SVOCs-benzo(a)pyrene, fluoranthene, and 2,3,7,8-tetrachlorodibenzo-p-dioxin. The approach presented here provides a useful framework and starting point for source-to-intake assessments for the ambient air-to-dietary exposure pathway.

  11. 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

  12. 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.

  13. Methyldibromo glutaronitrile: clinical experience and exposure-based risk assessment.

    PubMed

    Zachariae, Claus; Rastogi, Suresh; Devantier, Charlotte; Menné, Torkil; Johansen, Jeanne Duus

    2003-03-01

    In the year 2000, the level of methyldibromo glutaronitrile (MDGN) allergy in dermatology clinics in Europe exceeded the level of allergies to all other preservatives, with a prevalence of 3.5%. In the present study, cases of primary sensitization and elicitation to MDGN due to cosmetic products were collected over an 8-month period at the Department of Dermatology, Gentofte University Hospital. The aim was to identify the products related to hand eczema, assess exposure to MDGN in these products and relate the findings to results from a newly developed updated risk assessment model for contact allergy. Out of 24 patients with a positive patch test to MDGN, 17 patients with hand eczema were identified. In 11 of these patients, cosmetic products used in relation to the onset of the disease were shown to contain MDGN (65%). In 8 of these 11 cases, primary sensitization was probable, 5 due to hand/body lotions and 3 due to lotions and/or liquid hand soap. Chemical analysis of 12 products showed that lotions contained 149-390 ppm of MDGN, liquid hand soap 144-399 ppm, a rinsing cream 293 ppm and shampoos 78-79 ppm. The shampoo exposure was not of certain relevance to the eczema. Applying the newly developed updated risk assessment model showed that the concentrations of MDGN in lotions of 149-390 ppm exceeded the calculated maximum acceptable exposure level for MDGN, which would be expected to lead to sensitization in consumers using such products, as seen in the current study. The present cases and updated exposure-based risk assessment process add to the evidence and need for re-defining safe-use concentrations of MDGN in cosmetic products.

  14. Human exposure assessment and the National Toxicology Program.

    PubMed Central

    Lucier, G W; Schecter, A

    1998-01-01

    The National Institute of Environmental Health Sciences/National Toxicology Program (NIEHS/NTP) is developing a new interagency initiative in exposure assessment. This initiative involves the NIEHS, the Centers for Disease Control and Prevention through its National Center for Environmental Health, the National Institute for Occupational Safety and Health, the EPA, and other participating institutes and agencies of the NTP. This initiative will benefit public health and priority setting in a number of ways. First, as discussed above, it will strengthen the scientific foundation for risk assessments by the development of more credible exposure/response relationships in people by improving cross-species extrapolation, the development of biologically based dose-response models, and the identification of sensitive subpopulations and for "margin of exposure" based estimates of risk. Second, it will provide the kind of information necessary for deciding which chemicals should be studied with the limited resources available for toxicological testing. For example, there are 85,000 chemicals in commerce today, and the NTP can only provide toxicological evaluations on 10-20 per year. Third, we would use the information obtained from the exposure initiative to focus our research on mixtures that are actually present in people's bodies. Fourth, we would obtain information on the kinds and amount of chemicals in children and other potentially sensitive subpopulations. Determinations of whether additional safety factors need to be applied to children must rest, in part, upon comparative exposure analyses between children and adults. Fifth, this initiative, taken together with the environmental genome initiative, will provide the science base essential for meaningful studies on gene/environment interactions, particularly for strengthening the evaluation of epidemiology studies. Sixth, efficacy of public health policies aimed at reducing human exposure to chemical agents could be

  15. 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

  16. 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....

  17. 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...

  18. 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...

  19. 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

  20. Assessment of human exposure to environmental sources of nickel in Europe: Inhalation exposure.

    PubMed

    Buekers, Jurgen; De Brouwere, Katleen; Lefebvre, Wouter; Willems, Hanny; Vandenbroele, Marleen; Van Sprang, Patrick; Eliat-Eliat, Maxime; Hicks, Keegan; Schlekat, Christian E; Oller, Adriana R

    2015-07-15

    The paper describes the inhalation nickel (Ni) exposure of humans via the environment for the regional scale in the EU, together with a tiered approach for assessing additional local exposure from industrial emissions. The approach was designed, in the context of REACH, for the purpose of assessing and controlling emissions and air quality in the neighbourhood of Ni producers and downstream users. Two Derived No Effect Level (DNEL) values for chronic inhalation exposure to total Ni in PM10 (20 and 60ngNi/m(3)) were considered. The value of 20ngNi/m(3) is the current EU air quality guidance value. The value of 60ngNi/m(3) is derived here based on recently published Ni data (Oller et al., 2014). Both values are protective for respiratory toxicity and carcinogenicity but differ in the application of toxicokinetic adjustments and cancer threshold considerations. Estimates of air Ni concentrations at the European regional scale were derived from the database of the European Environment Agency. The 50th and 90th percentile regional exposures were below both DNEL values. To assess REACH compliance at the local scale, measured ambient air data are preferred but are often unavailable. A tiered approach for the use of modelled ambient air concentrations was developed, starting with the application of the default EUSES model and progressing to more sophisticated models. As an example, the tiered approach was applied to 33 EU Ni sulphate producers' and downstream users' sites. Applying the EUSES model demonstrates compliance with a DNEL of 60ngNi/m(3) for the majority of sites, while the value of the refined modelling is demonstrated when a DNEL of 20ngNi/m(3) is considered. The proposed approach, applicable to metals in general, can be used in the context of REACH, for refining the risk characterisation and guiding the selection of risk management measures. PMID:25863314

  1. 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

  2. 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

  3. Pesticide Exposure, Safety Issues, and Risk Assessment Indicators

    PubMed Central

    Damalas, Christos A.; Eleftherohorinos, Ilias G.

    2011-01-01

    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

  4. 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.

  5. Biomonitoring and Biomarkers: Exposure Assessment Will Never Be the Same

    PubMed Central

    Paustenbach, Dennis; Galbraith, David

    2006-01-01

    Using modern analytical technology, it is now possible to measure almost any chemical present in our bodies. The future role of classical exposure assessment will perhaps be marginalized because biomonitoring programs can directly measure the concentration of chemicals that are present in biologic matrices. Although the concentration of chemicals in the environment will continue to be measured and related to exposure parameters, the prioritization of the national environmental agenda will be dictated by biomonitoring. Recent biomonitoring studies have examined the levels of > 200 chemicals. Biomonitoring data, by themselves, are not informative in helping consumers understand their individual health risk. A major challenge facing those who conduct biomonitoring programs is how to best communicate the information to the public. In this article, we review benefits and challenges, along with select results from the Centers for Disease Control and Prevention’s 2005 National Report on Human Exposure to Environmental Chemicals. We recommend that these data be carefully interpreted, with the goal of establishing baseline exposure information, rather than creating surrogates for conclusions about human health risk. PMID:16882516

  6. Biomonitoring and biomarkers: exposure assessment will never be the same.

    PubMed

    Paustenbach, Dennis; Galbraith, David

    2006-08-01

    Using modern analytical technology, it is now possible to measure almost any chemical present in our bodies. The future role of classical exposure assessment will perhaps be marginalized because biomonitoring programs can directly measure the concentration of chemicals that are present in biologic matrices. Although the concentration of chemicals in the environment will continue to be measured and related to exposure parameters, the prioritization of the national environmental agenda will be dictated by biomonitoring. Recent biomonitoring studies have examined the levels of >200 chemicals. Biomonitoring data, by themselves, are not informative in helping consumers understand their individual health risk. A major challenge facing those who conduct biomonitoring programs is how to best communicate the information to the public. In this article, we review benefits and challenges, along with select results from the Centers for Disease Control and Prevention's 2005 National Report on Human Exposure to Environmental Chemicals. We recommend that these data be carefully interpreted, with the goal of establishing baseline exposure information, rather than creating surrogates for conclusions about human health risk.

  7. Is exposure to Agent Orange a risk factor for hepatocellular cancer?—A single-center retrospective study in the U.S. veteran population

    PubMed Central

    Hazratjee, Nyla; Opris, Dan; Agrawal, Sangeeta; Markert, Ronald

    2016-01-01

    Background Approximately 15% to 35% of those with chronic hepatitis C (CHC) related cirrhosis will develop hepatocellular cancer (HCC). With this burden increasing across the globe, identification of risk factors for HCC has become imperative. Exposure to Agent Orange has been implicated as a possible risk factor for liver cancer in a study from the Republic of Korea. However, there has been no study in U.S. veterans with CHC and cirrhosis that has evaluated exposure to Agent Orange as a risk factor for HCC. We conducted a retrospective study of U.S. military veterans diagnosed with CHC and cirrhosis over a period of 14 years to evaluate potential risk factors for HCC including exposure to Agent Orange. Methods We retrospectively reviewed 390 patients with confirmed CHC-related cirrhosis between 2000 and 2013 and identified patients with HCC. We compared demographic, laboratory, and other clinical characteristics of patients with and without HCC. Results The mean age of the cohort was 51 years (SD =7.5), with the majority being male (98.5%). Seventy-nine of 390 (20.2%) patients developed HCC, diagnosed on average 8 (SD =4.8) years after diagnosis of CHC. Nearly half (49.4%) were Childs A, 40.5% were Childs B, and 10.1% were Childs C. HCC patients were more likely to be African American than non-HCC patients (40.5% vs. 25.4%, P=0.009) and to be addicted to alcohol (86.1% vs. 74.3%, P=0.027). A trend toward significance was seen in the HCC group for exposure to Agent Orange (16.5% vs. 10.0%, P=0.10) and smoking addiction (88.6% vs. 80.7%, P=0.10). Consequently, race, alcohol addiction, Agent Orange exposure, and smoking addiction were included in the multivariable logistic regression (MLR) analysis. Alcohol addiction [odds ratio (OR) =2.17; 95% confidence interval (CI), 1.07–4.43] and African American race (OR =2.07; 95% CI, 1.22–3.51) were found to be the only two definitive independent risk factors for HCC in our sample. Conclusions African American race and

  8. Personal exposure meets risk assessment: a comparison of measured and modeled exposures and risks in an urban community.

    PubMed Central

    Payne-Sturges, Devon C; Burke, Thomas A; Breysse, Patrick; Diener-West, Marie; Buckley, Timothy J

    2004-01-01

    Human exposure research has consistently shown that, for most volatile organic compounds (VOCs), personal exposures are vastly different from outdoor air concentrations. Therefore, risk estimates based on ambient measurements may over- or underestimate risk, leading to ineffective or inefficient management strategies. In the present study we examine the extent of exposure misclassification and its impact on risk for exposure estimated by the U.S. Environmental Protection Agency (U.S. EPA) Assessment System for Population Exposure Nationwide (ASPEN) model relative to monitoring results from a community-based exposure assessment conducted in Baltimore, Maryland (USA). This study is the first direct comparison of the ASPEN model (as used by the U.S. EPA for the Cumulative Exposure Project and subsequently the National-Scale Air Toxics Assessment) and human exposure data to estimate health risks. A random sampling strategy was used to recruit 33 nonsmoking adult community residents. Passive air sampling badges were used to assess 3-day time-weighted-average personal exposure as well as outdoor and indoor residential concentrations of VOCs for each study participant. In general, personal exposures were greater than indoor VOC concentrations, which were greater than outdoor VOC concentrations. Public health risks due to actual personal exposures were estimated. In comparing measured personal exposures and indoor and outdoor VOC concentrations with ASPEN model estimates for ambient concentrations, our data suggest that ASPEN was reasonably accurate as a surrogate for personal exposures (measured exposures of community residents) for VOCs emitted primarily from mobile sources or VOCs that occur as global "background" source pollutant with no indoor source contributions. Otherwise, the ASPEN model estimates were generally lower than measured personal exposures and the estimated health risks. ASPEN's lower exposures resulted in proportional underestimation of cumulative

  9. 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.

  10. 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. PMID:25582860

  11. A retrospective approach to assess human health risks associated with growing air pollution in urbanized area of Thar Desert, western Rajasthan, India

    PubMed Central

    2014-01-01

    Air pollution has been a matter of great concern globally because of the associated health risks to individuals. The situation is getting worse in developing countries with more urbanization, industrialization and more importantly the rapidly growing population posing a threat to human life in the form of pulmonary, cardiovascular, carcinogenic or asthmatic diseases by accumulating toxic pollutants, harmful gases, metals, hydrocarbons etc. Objective The present study was undertaken to assess the magnitude of ambient air pollutants and their human health risks like respiratory ailments, infectious diseases, cardiovascular diseases and cancer using a Retrospective Approach of Bart Ostra. Methodology The parameters PM2.5, PM10, NOx, SO2, NH3 and O3 were monitored at all selected study sites monitored through a high volume sampler (APM 451 Envirotech, Envirotech Instruments Pvt. Ltd., New Delhi, India). Retrospective Approach was used for assessment of risk factors and disease burden of respiratory and cardiopulmonary health problems. Results Environmental burden of disease showed that the problem of health related to air pollution is a main concern particularly in the growing cities of India. High to critical level of air pollution including PM10, PM2.5, NOx, SO2, NH3 and O3 was observed in all seasons at traffic intersections and commercial sites. The respiratory infections (25% incidence in population exposed to indoor smoke problems) and a prevalence of asthma/COPD (4.4%) in households exposed to high vehicular pollution along with signs of coronary artery/heart disease and/or hypertension and cancers (37.9-52.2%), were reported requiring preventive measures. Conclusion The study reflects a great concern for the mankind with the need of having streamline ways to limit air pollution and emphasize upon efficiently determining the risk of illness upon exposure to air pollution. PMID:24406114

  12. 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.

  13. 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

  14. 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.

  15. 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. PMID:26364754

  16. 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...

  17. 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.

  18. 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. PMID:21503692

  19. Application of POCIS for exposure assessment of munitions constituents during constant and fluctuating exposure.

    PubMed

    Belden, Jason B; Lotufo, Guilherme R; Biedenbach, James M; Sieve, Kristal K; Rosen, Gunther

    2015-05-01

    The present study examined the potential use of polar organic chemical integrative samplers (POCIS) for exposure assessment of munitions constituents, including 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and their breakdown products (aminodinitrotoluenes [ADNTs], diaminonitrotoluenes [DANTs], and hexahydro-1,3,5-trinitroso-1,3,5-triazine [TNX]). Loss of munitions constituents from the sorbent phase after uptake was observed for the "pesticide" POCIS configuration but not for the "pharmaceutical" configuration. Therefore, the latter was selected for further investigation. Under constant exposure conditions, TNT, ADNTs, DANT, RDX, and atrazine (a common environmental contaminant) accumulated at a linear rate for at least 14 d, with sampling rates between 34 mL/d and 215 mL/d. When POCIS were exposed to fluctuating concentrations, analyte accumulation values were similar to values found during constant exposure, indicating that the sampler was indeed integrative. In contrast, caffeine (a common polar contaminant) and TNX did not accumulate at a linear rate and had a reduction in accumulation of greater than 50% on the POCIS during fluctuating exposures, demonstrating that POCIS did not sample those chemicals in an integrative manner. Moreover, in a flow-through microcosm containing the explosive formulation Composition B, TNT and RDX were readily measured using POCIS, despite relatively high turnover rates and thus reduced water concentrations. Mean water concentrations estimated from POCIS were ± 37% of mean water concentrations measured by traditional grab sample collection. Thus, POCIS were found to have high utility for quantifying exposure to most munitions constituents evaluated (TNT, ADNTs, and RDX) and atrazine. PMID:25475692

  20. 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

  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. Assessment of mortality in patients enrolled in a risedronate clinical trial program: a retrospective cohort study.

    PubMed

    Steinbuch, Michael; D'Agostino, Ralph B; Mandel, Jack S; Gabrielson, Edward; McClung, Michael R; Stemhagen, Annette; Hofman, Albert

    2002-06-01

    Risedronate, a pyridinyl bisphosphonate, has been shown in large clinical trials to be effective in the prevention and treatment of osteoporosis. Analysis of safety data from these trials has shown that risedronate (2.5- and 5-mg doses) has an overall safety profile comparable to placebo during the course of the clinical trials. The clinical trials were powered appropriately to analyze the efficacy endpoints; however, patients were not systematically followed after completion of the clinical trials and therefore vital status for most of the patient cohort after the cessation of the clinical trials was unknown. In order to investigate further the safety profile of risedronate observed in the clinical trials database, we conducted a retrospective cohort mortality study among 7981 patients comprising the intent-to-treat population in three North American risedronate osteoporosis trials. No difference in all cause mortality was observed in patients receiving risedronate treatment compared with patients receiving placebo. There were also no differences between these groups in mortality due to all cancers, lung cancer, and gastrointestinal tract cancer. A trend toward lower cardiovascular mortality was observed in the risedronate groups compared with placebo; this difference was largely due to a significant reduction in stroke mortality in the active treatment groups. Follow-up mortality data in this retrospective cohort study demonstrate that treatment with risedronate has no effect on overall mortality rates.

  3. Assessment of retrospective dose estimation, with fluorescence in situ hybridization (FISH), of six victims previously exposed to accidental ionizing radiation.

    PubMed

    Liu, Qing-Jie; Lu, Xue; Zhao, Xiao-Tao; Feng, Jiang-Bin; Lü, Yu-Min; Jiang, En-Hai; Zhang, Shu-Lan; Chen, De-Qing; Jia, Ting-Zhen; Liang, Li

    2014-01-01

    The present study aims to evaluate the use of the fluorescence in situ hybridization (FISH) translocation assay for retrospective dose estimation of acute accidental exposure to radiation in the past. Reciprocal translocation analysis by FISH with three whole-chromosome probes was performed on normal peripheral blood samples. Samples were irradiated with 0-5Gy (60)Co γ-rays in vitro, and dose-effect curves were established. FISH-based translocation analyses for six accident victims were then performed, and biological doses were estimated retrospectively by comparison with the dose-effect curves. Reconstructed doses by FISH were compared with estimated doses obtained by analysis of di-centrics performed soon after exposure, or with dose estimates from tooth-enamel electron paramagnetic resonance (EPR) data obtained at the same time as the FISH analysis. Follow-up FISH analyses for an adolescent victim were performed. Results showed that dose-effect curves established in the present study follow a linear-quadratic model, regardless of the background translocation frequency. Estimated doses according to two dose-effect curves for all six victims were similar. FISH dose estimations of three adult victims exposed to accidental radiation less than a decade prior to analysis (3, 6, or 7 years ago) were consistent with those estimated with tooth-enamel EPR measurements or analyses of di-centrics. Estimated doses of two other adult victims exposed to radiation over a decade prior to analysis (16 or 33 years ago) were underestimated and two to three times lower than the values obtained from analysis of di-centrics or tooth-enamel EPR. Follow-up analyses of the adolescent victim showed that doses estimated by FISH analysis decrease rapidly over time. Therefore, the accuracy of dose estimates by FISH is acceptable only when analysis is performed less than 7 years after exposure. Measurements carried out more than a decade after exposure through FISH analysis resulted in

  4. 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.

  5. The influence of maternal smoking and exposure to residential ETS on pregnancy outcomes: a retrospective national study.

    PubMed

    Krstev, Srmena; Marinković, Jelena; Simić, Snežana; Kocev, Nikola; Bondy, Susan J

    2013-11-01

    In a nationwide study of Serbian births, in 2008, we estimated the influence of maternal prenatal smoking and environmental tobacco smoke (ETS) exposure on birth outcomes. Using stratified two-stage random cluster sampling, 2,721 women were interviewed in-person (response rates 98.1 %), and 2,613 singleton live births were included. Date of birth, gender, birthweight, birth height and head circumference were copied from the official hospital Birth Certificate. Six exposure categories were defined according to mother's smoking history and exposure to ETS. We calculated adjusted mean values and group differences by analysis of covariance, and adjusted odds ratios for the low birthweight (LBW < 2,500 g). Compared to the reference category (non-smoking, non-exposed to ETS) we observed birthweight reductions in infants whose mothers smoked continuously during the pregnancy and were exposed to ETS (-162.6 g) and whose mothers were not exposed to ETS (-173 g) (p = 0.000, and p = 0.003, respectively), as well as reduction in birth length (-1.01 and -1.06 cm; p = 0.003 and p = 0.000, respectively). Reduction in birthweight and birth length related to exposure categories was not linear. Adjusted OR for LBW was almost tripled for mothers who smoked over the entire pregnancy and were non-exposed to ETS (aOR 2.85; 95 % CI 1.46-5.08), and who were exposed to ETS (aOR 2.68; 95 % CI 1.15-6.25). Our results showed strong effects of smoking throughout the pregnancy on reduced birthweight, birth length and head circumference, and increased risk for LBW. We were not able to detect an effect for ETS exposure alone. PMID:23090285

  6. Affinity for risky behaviors following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study

    PubMed Central

    2011-01-01

    Background Many studies of adults with acute and chronic solvent exposure have shown adverse effects on cognition, behavior and mood. No prior study has investigated the long-term impact of prenatal and early childhood exposure to the solvent tetrachloroethylene (PCE) on the affinity for risky behaviors, defined as smoking, drinking or drug use as a teen or adult. Objectives This retrospective cohort study examined whether early life exposure to PCE-contaminated drinking water influenced the occurrence of cigarette smoking, alcohol consumption, and drug use among adults from Cape Cod, Massachusetts. Methods Eight hundred and thirty-one subjects with prenatal and early childhood PCE exposure and 547 unexposed subjects were studied. Participants completed questionnaires to gather information on risky behaviors as a teenager and young adult, demographic characteristics, other sources of solvent exposure, and residences from birth through 1990. PCE exposure was estimated using the U.S. EPA's water distribution system modeling software (EPANET) that was modified to incorporate a leaching and transport model to estimate PCE exposures from pipe linings. Results Individuals who were highly exposed to PCE-contaminated drinking water during gestation and early childhood experienced 50-60% increases in the risk of using two or more major illicit drugs as a teenager or as an adult (Relative Risk (RR) for teen use = 1.6, 95% CI: 1.2-2.2; and RR for adult use = 1.5, 95% CI: 1.2-1.9). Specific drugs for which increased risks were observed included crack/cocaine, psychedelics/hallucinogens, club/designer drugs, Ritalin without a prescription, and heroin (RRs:1.4-2.1). Thirty to 60% increases in the risk of certain smoking and drinking behaviors were also seen among highly exposed subjects. Conclusions The results of this study suggest that risky behaviors, particularly drug use, are more frequent among adults with high PCE exposure levels during gestation and early childhood

  7. A retrospective tiered environmental assessment of the Mount Storm Wind Energy Facility, West Virginia,USA

    SciTech Connect

    Efroymson, Rebecca Ann; Day, Robin; Strickland, M. Dale

    2012-11-01

    Bird and bat fatalities from wind energy projects are an environmental and public concern, with post-construction fatalities sometimes differing from predictions. Siting facilities in this context can be a challenge. In March 2012 the U.S. Fish and Wildlife Service (USFWS) released Land-based Wind Energy Guidelines to assess collision fatalities and other potential impacts to species of concern and their habitats to aid in siting and management. The Guidelines recommend a tiered approach for assessing risk to wildlife, including a preliminary site evaluation that may evaluate alternative sites, a site characterization, field studies to document wildlife and habitat and to predict project impacts, post construction studies to estimate impacts, and other post construction studies. We applied the tiered assessment framework to a case study site, the Mount Storm Wind Energy Facility in Grant County, West Virginia, USA, to demonstrate the use of the USFWS assessment approach, to indicate how the use of a tiered assessment framework might have altered outputs of wildlife assessments previously undertaken for the case study site, and to assess benefits of a tiered ecological assessment framework for siting wind energy facilities. The conclusions of this tiered assessment for birds are similar to those of previous environmental assessments for Mount Storm. This assessment found risk to individual migratory tree-roosting bats that was not emphasized in previous preconstruction assessments. Differences compared to previous environmental assessments are more related to knowledge accrued in the past 10 years rather than to the tiered structure of the Guidelines. Benefits of the tiered assessment framework include good communication among stakeholders, clear decision points, a standard assessment trajectory, narrowing the list of species of concern, improving study protocols, promoting consideration of population-level effects, promoting adaptive management through post

  8. 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.

  9. 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.

  10. 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. PMID:25249274

  11. 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

  12. 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

  13. Agricultural burning smoke in Eastern Washington: Part II. Exposure assessment

    NASA Astrophysics Data System (ADS)

    Wu, Chang-Fu; Jimenez, Jorge; Claiborn, Candis; Gould, Tim; Simpson, Christopher D.; Larson, Tim; Sally Liu, L.-J.

    Several studies have documented potential health effects due to agricultural burning smoke. However, there is a paucity of literature characterizing community residents' exposure to agricultural burning smoke. This study assesses personal exposures to particulate matter (PM) with aerodynamic diameters <2.5 μm (PM 2.5) from agriculture burning smoke ( Eb) for 33 asthmatic adults in Pullman, WA. PM 2.5 concentrations were measured on 16 subjects, inside of all but four residences, outside of 6 residences, and at a central site. The mean±standard deviation of personal exposure to PM 2.5 was 13.8±11.1 μg m -3, which was on average 8.0 μg m -3 higher during the agricultural burning episodes (19.0±11.8 μg m -3) than non-episodes (11.0±9.7 μg m -3). The levoglucosan (LG, a unique marker for biomass burning PM) on personal filter samples also was higher during the episodes than non-episodes (0.026±0.030 vs. 0.010±0.012 μg m -3). We applied the random component superposition model on central-site and home indoor PM measurements, and estimated a central-site infiltration factor between 0.21 and 2.05 for residences with good modeling performance. We combined the source apportionment and total exposure modeling results to estimate individual Eb, which ranged from 1.2 to 6.7 μg m -3 and correlated with personal LG with an r of 0.51. The sensitivity analysis of applying the infiltration efficiency estimated from the recursive model showed that the Eb (range: 1.3-4.3 μg m -3) obtained from this approach have a higher correlation with personal LG ( r=0.75). Nevertheless, the small sample size of personal LG measurements prevents a comparative and conclusive assessment of the model performance. We found a significant between-subject variation between episodes and non-episodes in both the Eb estimates and subjects' activity patterns. This suggests that the LG measurements at the central site may not always represent individual exposures to agricultural burning smoke

  14. Spatiotemporal air pollution exposure assessment for a Canadian population-based lung cancer case-control study

    PubMed Central

    2012-01-01

    Background Few epidemiological studies of air pollution have used residential histories to develop long-term retrospective exposure estimates for multiple ambient air pollutants and vehicle and industrial emissions. We present such an exposure assessment for a Canadian population-based lung cancer case-control study of 8353 individuals using self-reported residential histories from 1975 to 1994. We also examine the implications of disregarding and/or improperly accounting for residential mobility in long-term exposure assessments. Methods National spatial surfaces of ambient air pollution were compiled from recent satellite-based estimates (for PM2.5 and NO2) and a chemical transport model (for O3). The surfaces were adjusted with historical annual air pollution monitoring data, using either spatiotemporal interpolation or linear regression. Model evaluation was conducted using an independent ten percent subset of monitoring data per year. Proximity to major roads, incorporating a temporal weighting factor based on Canadian mobile-source emission estimates, was used to estimate exposure to vehicle emissions. A comprehensive inventory of geocoded industries was used to estimate proximity to major and minor industrial emissions. Results Calibration of the national PM2.5 surface using annual spatiotemporal interpolation predicted historical PM2.5 measurement data best (R2 = 0.51), while linear regression incorporating the national surfaces, a time-trend and population density best predicted historical concentrations of NO2 (R2 = 0.38) and O3 (R2 = 0.56). Applying the models to study participants residential histories between 1975 and 1994 resulted in mean PM2.5, NO2 and O3 exposures of 11.3 μg/m3 (SD = 2.6), 17.7 ppb (4.1), and 26.4 ppb (3.4) respectively. On average, individuals lived within 300 m of a highway for 2.9 years (15% of exposure-years) and within 3 km of a major industrial emitter for 6.4 years (32% of exposure-years). Approximately 50% of individuals

  15. An improved method for retrospective quantification of sulfur mustard exposure by detection of its albumin adduct using ultra-high pressure liquid chromatography-tandem mass spectrometry.

    PubMed

    Liu, ChangCai; Liang, LongHui; Xiang, Yu; Yu, HuiLan; Zhou, ShiKun; Xi, HaiLing; Liu, ShiLei; Liu, JingQuan

    2015-09-01

    Sulfur mustard (HD) adduct to human serum albumin (ALB) at Cys-34 residue has become an important and long-term retrospective biomarker of HD exposure. Here, a novel, sensitive, and convenient approach for retrospective quantification of HD concentration exposed to plasma was established by detection of the HD-ALB adduct using ultra-high pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with a novel non-isotope internal standard (IS). The HD-ALB adduct was isolated from HD-exposed plasma with blue Sepharose. The adduct was digested with proteinase K to form sulfur-hydroxyethylthioethyl ([S-HETE])-Cys-Pro-Phe tripeptide biomarker. The tripeptide adduct could be directly analyzed by UHPLC-MS/MS without an additional solid phase extraction (SPE), which was considered as a critical procedure in previous methods. The easily available 2-chloroethyl ethylsulfide (2-CEES) as HD surrogate was first reported to be used as IS in place of traditional d8-HD for quantification of HD exposure. Furthermore, 2-CEES was also confirmed to be a good IS alternative for quantification of HD exposure by investigation of product ion spectra for their corresponding tripeptide adducts which exhibited identical MS/MS fragmentation behaviors. The method was found to be linear between 1.00 and 250 ng•mL(-1) HD exposure (R(2)>0.9989) with precision of <4.50% relative standard deviation (%RSD), accuracy range between 96.5% and 114%, and a calculated limit of detection (LOD) of 0.532 ng•mL(-1). The lowest reportable limit (LRL) is 1.00 ng•mL(-1), over seven times lower than that of the previous method. The entire method required only 0.1 mL of plasma sample and took under 7 h without special sample preparation equipment. It is proven to be a sensitive, simple, and rugged method, which is easily applied in international laboratories to improve the capabilities for the analysis of biomedical samples related to verification of the Chemical Weapon Convention (CWC).

  16. Health risk assessment for inhalation exposure to arsenic.

    PubMed

    Fabiánová, E; Hettychová, L; Koppová, K; Hrubá, F; Marko, M; Maroni, M; Grech, G; Bencko, V

    2000-02-01

    Health risk assessment was used as the formal process to estimate the likelihood and magnitude of the health effects occurring in humans as a result of environmental and occupational exposure to polluting agents. This study was focused at estimating the human health risk of the general and working population living in the region polluted by arsenic for more than 40 years, from combustion of coal with high arsenic content in the power plant. The exposure to arsenic from inhalation was under investigation. A study period of 40 years (1973-1993) was chosen. The study period was defined taking into account, besides the availability of data, the temporal patterns of the technological processes and the trends over time of environmental concentrations. The results from the arsenic risk assessment study were used for the evaluation of the health risk for different population groups in the polluted areas and for different professions of workers exposed to As in a power plant. The results are applicable for the evaluation of risk in real conditions, for health surveillance and for remedial changes and a potential suggestion on technological improvement.

  17. 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.

  18. 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.

  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 human exposures to animal vaccines using poison control records, 2000-2009.

    PubMed

    Edison, L; Schulte, J; Schauben, J; Kay, R; Rubin, C

    2014-05-01

    To characterize human exposures to vaccines intended for animals, evaluate the human risk due to these exposures and determine whether there is sufficient surveillance in place to monitor them. Retrospective analysis of surveillance data (2000-2009). Information collected by poison specialists during calls reporting human exposure to an animal vaccine product, made to one of the 57 United States Poison Control Centers. Data from the National Poison Data System were analysed to determine the number of calls due to human exposures to animal vaccines, and descriptive statistics were generated to characterize the exposures by age, gender, medical outcome, exposure site, exposure route, vaccine type and intended species, aetiologic agent, call date and exposure reason. Overall, the human health effects were minor, primarily due to unintentional parenteral exposure. Less than 15% of the reports were classified as occupational, and 80% of the exposures took place outside of a workplace or healthcare facility. Almost 60% of calls were due to exposure to the West Nile Virus vaccine; the others distributed among a variety of vaccines. Unintentional exposure to animal vaccines appears to occur almost exclusively among untrained individuals who may benefit from more effective education about the risks and benefits of administering vaccines. Improved reporting of adverse outcomes is essential to adequately define the extent of human exposure and risks associated with availability of new vaccines.

  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. An assessment of exposure indices in computed radiography for the posterior-anterior chest and the lateral lumbar spine.

    PubMed

    Warren-Forward, H; Arthur, L; Hobson, L; Skinner, R; Watts, A; Clapham, K; Lou, D; Cook, A

    2007-01-01

    Studies have indicated that computed radiography (CR) can increase radiation dose to the patient, leading to potential biological effects. Although manufacturers have set parameters to safeguard against overexposure, it is unclear whether these are being used by radiographers or if their recommended values are consistent with the ALARA principle. The research aims are to investigate (i) whether radiographers are producing images with exposure indices within the manufacturers recommended range (MRR); (ii) the phenomenon of exposure creep, and (iii) the relationship between exposure indices (EIs) and radiation dose. A retrospective analysis of exposure indices over an 18-month period for the posteroanterior (PA) chest and lateral (LAT) lumbar spine at two centres using Kodak 800 and 850 CR systems was conducted. A phantom study was performed to assess the relationship between EI and entrance surface dose (ESD) for fixed and varying tube potentials. Kodak recommends that images have EIs between 1700 and 1900. Thirty percent of LAT lumbar spine examinations at hospital B and 38% of PA chest examinations at hospital A were produced with EIs below 1700. In the phantom study, when using a varied tube potential (70-125 kVp) and maintaining a constant EI of 1550, ESD was reduced by 56%. All clinical and phantom images were assessed to be of a diagnostic quality. The retrospective results indicate that there is a potential to reduce the MRR and optimize patient dose. There is also evidence to suggest that EI is not a reliable indicator of patient dose. The authors recommend that staff training is essential on these newer systems. PMID:16916804

  3. Challenges in Dietary Exposure Assessment in Epidemiology: Research Trends.

    PubMed

    Ishihara, Junko

    2015-01-01

    Although exposure assessment of the usual diet is an essential component of nutrition epidemiology, it remains one of the most challenging issues in the field. Dietary exposure is widely measured using Food Frequency Questionnaires (FFQs), which impose a low burden on respondents and are inexpensive in large-scale studies. FFQs have long satisfied the needs of epidemiological research, and have helped deliver the tremendous recent growth in knowledge of the diet-disease association. However, issues surrounding measurement errors with FFQs have attracted substantial research interest around the world. Attenuation of the diet-disease association due to measurement errors identified in Western populations has led to extended methodological investigations comparing the performance of FFQs with biomarkers. The need for better dietary assessment methods has increased. Dietary records or recall provide relatively accurate estimates of intake for specific days, and of the usual diet if collected on multiple days. Until recently, however, their use in large-scale studies was not feasible, mainly due to cost. One innovative tool which may overcome the limitations of dietary records or recall is computerized 24-h dietary recall systems. These systems have been demonstrated to provide high-quality dietary intake data among Western populations. Incorporation of such new technology into large-scale epidemiological studies would make multiple-day administration of 24-h recall feasible in terms of cost. Research efforts to improve dietary assessment among Japanese and Asian populations are still under development. The development of innovative methods for Japanese remains an urgent research challenge. PMID:26598878

  4. A cross-lagged analysis of the relationship between symptoms of PTSD and retrospective reports of exposure.

    PubMed

    Bolton, Elisa E; Gray, Matthew J; Litz, Brett T

    2006-01-01

    As part of a larger longitudinal investigation, 522 U.S. peacekeepers who served in Somalia were administered a comprehensive psychosocial questionnaire. The questionnaire included the PTSD Checklist [PCL; Weathers, F. W., Litz, B. T., Herman, D. S., Huska, J. A., & Keane, T. M. (1993, November). The PTSD Checklist (PCL): reliability, validity, and diagnostic utility. Paper presented at the annual meeting of the International Society for Traumatic Stress Studies, San Antonio, TX], the Mississippi Scale [Keane, T. M., Caddell, J. M., & Taylor, K. L. (1988). Mississippi Scale for combat-related posttraumatic stress disorder: three studies in reliability and validity. Journal of Consulting and Clinical Psychology, 56, 85-90], the War-Zone Exposure Scale [WZES; Litz, B. T., Orsillo, S. M, Freidman, M., Ehlich, P., & Batres, A. (1997). Posttraumatic stress disorder associated with peacekeeping duty in Somalia for US military personnel. American Journal of Psychiatry, 154(2), 178-184], and the Other Stressors Associated with Peacekeeping Scale [Litz, B. T., King, L. A., King, D. W., Orsillo, S. M., & Friedman, M. J. (1997). Warriors as peacekeepers: features of the Somalia experience and PTSD. Journal of Consulting and Clinical Psychology, 65, 1001-1010]. These measures were administered approximately 15 weeks postdeployment and roughly a year and a half later. Using a cross-lagged panel design, PTSD symptom severity was associated with increases in reports of exposure at Time 2. However, this finding was modest and was not specific to the recall of traumatic events. PMID:16530379

  5. Novel Jumbo Biopsy Forceps for Surveillance of Inflammatory Bowel Disease: A Comparative Retrospective Assessment

    PubMed Central

    Song, Kenneth; Toweill, Daniel; Rulyak, Stephen J.; Lee, Scott D.

    2011-01-01

    Background and Study Aims. Most available jumbo cup forceps require a 3.7 mm biopsy channel, necessitating the use of standard-sized colonoscope. A newer jumbo forceps (Radial Jaw 4 Jumbo Biopsy Forceps [RJ4]) fits within a 3.2 mm biopsy channel, allowing use with a pediatric colonoscope. To assure the RJ4 did not alter biopsy adequacy, we compared the size and quality of specimens to a historical jumbo cup forceps (Radial Jaw 3 Max Capacity Biopsy Forceps, [RJ3 MC]). Patients and Methods. A retrospective comparative study of biopsies taken with either forceps. Biopsies were compared for diameter, depth, crush artifact, and acceptability for diagnosis. Results. 333 specimens were taken with RJ4 and 335 specimens with the RJ3 MC. Mean sample diameter was 4.45 mm and 4.55 mm for the RJ4 and RJ3 MC (P = 0.41). Mean depth of biopsies with the RJ4 was greater (P < 0.01). Conclusions. Biopsies from the RJ4 are similar in size and quality to biopsies from the RJ3 MC. The RJ4 has the advantage of fitting in a smaller biopsy channel. PMID:22007197

  6. Novel jumbo biopsy forceps for surveillance of inflammatory bowel disease: a comparative retrospective assessment.

    PubMed

    Song, Kenneth; Toweill, Daniel; Rulyak, Stephen J; Lee, Scott D

    2011-01-01

    Background and Study Aims. Most available jumbo cup forceps require a 3.7 mm biopsy channel, necessitating the use of standard-sized colonoscope. A newer jumbo forceps (Radial Jaw 4 Jumbo Biopsy Forceps [RJ4]) fits within a 3.2 mm biopsy channel, allowing use with a pediatric colonoscope. To assure the RJ4 did not alter biopsy adequacy, we compared the size and quality of specimens to a historical jumbo cup forceps (Radial Jaw 3 Max Capacity Biopsy Forceps, [RJ3 MC]). Patients and Methods. A retrospective comparative study of biopsies taken with either forceps. Biopsies were compared for diameter, depth, crush artifact, and acceptability for diagnosis. Results. 333 specimens were taken with RJ4 and 335 specimens with the RJ3 MC. Mean sample diameter was 4.45 mm and 4.55 mm for the RJ4 and RJ3 MC (P = 0.41). Mean depth of biopsies with the RJ4 was greater (P < 0.01). Conclusions. Biopsies from the RJ4 are similar in size and quality to biopsies from the RJ3 MC. The RJ4 has the advantage of fitting in a smaller biopsy channel.

  7. 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.

  8. 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. PMID:27283207

  9. 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 ...

  10. 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...

  11. 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

  12. 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

  13. 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 ...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Personalized Cancer Risk Assessments for Space Radiation Exposures.

    PubMed

    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

  19. Assessing exposure to cosmic radiation on board aircraft.

    PubMed

    Bottollier-Depois, J F; Chau, Q; Bouisset, P; Kerlau, G; Plawinski, L; Lebaron-Jacobs, L

    2003-01-01

    The assessment of exposure to cosmic radiation on board aircraft is one of the preoccupations of organizations responsible for radiation protection. The cosmic radiation particle flux increases with altitude and latitude and depends on the solar activity. The radiation exposure has been estimated on several airlines using transatlantic, Siberian and transequatorial routes on board subsonic and supersonic aircraft, to illustrate the effect of these parameters. Measurements have been obtained with a tissue equivalent proportional counter using the microdosimetric technique. Data have been collected at maximum solar activity in 1991-92 and at minimum in 1996-98. The lowest mean dose rate measured was 3 microSv/h during a Paris-Buenos Aires flight in 1991; the highest was 6.6 microSv/h during a Paris-Tokyo flight using a Siberian route and 9.7 microSv/h on Concorde in 1996-97. The mean quality factor is around 1.8. The corresponding annual effective dose, based on 700 hours of flight for subsonic aircraft and 300 hours for Concorde, can be estimated between 2 mSv for least-exposed routes and 5 mSv for more exposed routes.

  20. 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

  1. Organic dust exposures from compost handling: case presentation and respiratory exposure assessment.

    PubMed

    Weber, S; Kullman, G; Petsonk, E; Jones, W G; Olenchock, S; Sorenson, W; Parker, J; Marcelo-Baciu, R; Frazer, D; Castranova, V

    1993-10-01

    Inhalation of dust from contaminated organic materials may result in acute respiratory tract illness. Possible mechanisms include toxic and cellular reactions to microbial and other organic products or immunologic responses after prior sensitization to an antigen. A case is presented of a 52 year old male who developed fever, myalgia, and marked dyspnea 12 hr after shoveling composted wood chips and leaves. Inspiratory crackles, hypoxemia, and bilateral patchy pulmonary infiltrates were seen. Precipitating antibody tests for the usual antigens were inconclusive. He improved over 3 days. In order to assess the environmental conditions the patient had experienced, we returned to the site to reproduce and measure respiratory exposures during hand loading of the compost. Visible clouds of fine particulate were easily generated during handling activities. Microscopic examination of these dusts indicated a predominance of spores. Endotoxin concentrations from inspirable and respirable dust samples ranged from 636 to 16,300 endotoxin units/m3. Levels of contaminants found were consistent with those associated with respiratory illness in other agricultural settings. Two respiratory disorders, hypersensitivity pneumonitis (HP) and organic dust toxic syndrome (ODTS), may occur after exposure to organic dusts containing fungal spores and endotoxins. Despite extensive clinical and environmental investigations, we were unable to differentiate these two disorders, and suggest they may represent parts of a spectrum of responses to complex organic dusts, rather than completely distinct clinical entities.

  2. Advances in assessing the volume of odontogenic cysts and tumors in the mandible: a retrospective clinical trial

    PubMed Central

    2013-01-01

    Purpose To compare two methods of creating three-dimensional representations of mandibular cysts and tumors on the basis of computed tomography (CT) and cone beam computed tomography (CBCT) data. Methods A total of 71 patients with acquired jaw cysts took part in this retrospective clinical study. CT and CBCT scans were obtained from all patients and saved in the Digital Imaging and Communications in Medicine (DICOM) format. Data were analyzed twice with iPlan software. Analysis was performed manually and using an interpolarization algorithm. The accuracy of the two methods in assessing cyst volume was compared. Results Manual delineation did not provide more accurate results than the interpolarization algorithm. Conclusion There are no major differences between manual analysis and analysis using the interpolarization algorithm. The use of the algorithm, however, has the advantage of rapidity. PMID:23601144

  3. Evaluating the Discriminatory Power of a Computer-based System for Assessing Penetrating Trauma on Retrospective Multi-Center Data

    PubMed Central

    Matheny, Michael E.; Ogunyemi, Omolola I.; Rice, Phillip L.; Clarke, John R.

    2005-01-01

    Objective To evaluate the discriminatory power of TraumaSCAN-Web, a system for assessing penetrating trauma, using retrospective multi-center case data for gunshot and stab wounds to the thorax and abdomen. Methods 80 gunshot and 114 stab cases were evaluated using TraumaSCAN-Web. Areas under the Receiver Operator Characteristic Curves (AUC) were calculated for each condition modeled in TraumaSCAN-Web. Results Of the 23 conditions modeled by TraumaSCAN-Web, 19 were present in either the gunshot or stab case data. The gunshot AUCs ranged from 0.519 (pericardial tamponade) to 0.975 (right renal injury). The stab AUCs ranged from 0.701 (intestinal injury) to 1.000 (tracheal injury). PMID:16779090

  4. 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.

  5. Prenatal alcohol exposure: An assessment strategy for the legal context.

    PubMed

    Brown, Natalie Novick; Burd, Larry; Grant, Therese; Edwards, William; Adler, Richard; Streissguth, Ann

    2015-01-01

    Studies over the last two decades have shown that people with fetal alcohol spectrum disorders (FASD) have the kind of brain damage that increases risk of criminal behavior. Thus, it is generally accepted that FASD is likely to affect a sizable minority of individuals involved in the justice system. Most of these defendants have never been diagnosed because they lack the facial abnormalities and severe intellectual deficiency that would have improved identification and diagnosis in childhood. Despite the fact that an FASD diagnosis and associated cognitive deficits may be directly relevant to offense conduct and post-arrest capacities, screening for prenatal alcohol exposure (PAE) by legal teams remains relatively rare. This article addresses the relatively straightforward screening process with strategies that may be used singly or in combination to produce information that can establish PAE and provide a foundation for diagnostic assessment by medical and mental health experts. PMID:26338492

  6. {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.

  7. 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.

  8. Prenatal alcohol exposure: An assessment strategy for the legal context.

    PubMed

    Brown, Natalie Novick; Burd, Larry; Grant, Therese; Edwards, William; Adler, Richard; Streissguth, Ann

    2015-01-01

    Studies over the last two decades have shown that people with fetal alcohol spectrum disorders (FASD) have the kind of brain damage that increases risk of criminal behavior. Thus, it is generally accepted that FASD is likely to affect a sizable minority of individuals involved in the justice system. Most of these defendants have never been diagnosed because they lack the facial abnormalities and severe intellectual deficiency that would have improved identification and diagnosis in childhood. Despite the fact that an FASD diagnosis and associated cognitive deficits may be directly relevant to offense conduct and post-arrest capacities, screening for prenatal alcohol exposure (PAE) by legal teams remains relatively rare. This article addresses the relatively straightforward screening process with strategies that may be used singly or in combination to produce information that can establish PAE and provide a foundation for diagnostic assessment by medical and mental health experts.

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

    PubMed

    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.

  10. 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.

  11. Deoxynivalenol Exposure Assessment for Pregnant Women in Bangladesh.

    PubMed

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

    2015-10-01

    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

  12. Deoxynivalenol Exposure Assessment for Pregnant Women in Bangladesh

    PubMed Central

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

    2015-01-01

    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

  13. Radon exposure assessment in a former uranium production facility

    SciTech Connect

    Akbar-Khanzadch, F.; Merrill, E.A.

    1996-06-01

    Storage of radon-producing materials in three silos and six waste pits is one of the major environmental and occupational issues at a former uranium production facility, now a Superfund Site. The concentrations of radium up to 190,000 pCi g{sup -1} for silos and up to 1,200 pCi g{sup -1} for waste pits have been reported. This study was conducted to identify conditions and climatic factors that contribute to higher radon levels and to assess workers` exposure at the site. Data covering a 12-mo period were compiled from monitoring radon levels by hourly real-time indoor (within 3 buildings) and outdoor (at 14 on-site and 2 off-site stations) and from hourly site specific meteorological information. The ranges of radon levels were 0.05-98.8 pCi L{sup -1} outdoor on-site, 0.1-8.9 pCi L{sup -1} outdoor off-side, and 0.05-3.0 pCi L{sup -1} indoor on-site. Only radon levels in the vicinity of the storage silos, which is an exclusion zone, were significantly higher than levels off-site. Significantly higher levels of radon were detected in the production areas vs. those at the perimeter areas, suggesting that there were significant sources of on-site radon contamination other than the silos. Radon concentrations showed diurnal variations, maximum levels occurring at early morning and minimum levels in the afternoon. A seasonal variation was also observed, with radon levels highest during mid summer while lowest during winter. Wind direction, wind speed, relative humidity, and ambient temperature appeared to be the most significant predictors of radon concentration. The dose, calculated by using exposure models and annual average levels of radon in the work area, was below recommended exposure limits. These results suggest that the emission control methods at this site have been effective in maintaining environmental radon contamination and workers` exposure at acceptable levels.

  14. 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

  15. Improving Exposure Science and Dose Metrics for Toxicity Testing, Screening, Prioritizing, and Risk Assessment

    EPA Science Inventory

    Advance the characterization of exposure and dose metrics required to translate advances and findings in computational toxicology to information that can be directly used to support exposure and risk assessment for decision making and improved public health.

  16. 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...

  17. ARE ALL ARSENIC EXPOSURES TOXIC? SUPPORTING REGIONAL RISK ASSESSMENTS THROUGH IMPROVED ARSENIC SPECIATION METHODOLOGY

    EPA Science Inventory

    Arsenic exposure assessments require the evaluation of the relative contribution of both media (water, food, etc.) and routes of exposure (ingestion, inhalation, dermal). For arsenic, the important media are predominately water and food and therefore, the route of concern for ...

  18. A Retrospective Chart Study: The Pathway to a Diagnosis for Adults Referred for ASD Assessment

    ERIC Educational Resources Information Center

    Geurts, Hilde M.; Jansen, Marcel D.

    2012-01-01

    Charts of 125 adults (18 to 82 years), referred to an autism expert team for Autism Spectrum Disorder (ASD) assessment, were reviewed to explore the pathway to an adulthood ASD diagnosis. The participants first contacted the mental health care clinic at a median age of 19 years (range 2 to 78 years). Men contacted the clinic slightly earlier than…

  19. Assessing Early Communication Skills at 12 Months: A Retrospective Study of Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Swain, Nathaniel Robert; Eadie, Patricia Ann; Prior, Margot Ruth; Reilly, Sheena

    2015-01-01

    Background: Early identification of Autism Spectrum Disorder (ASD) is currently limited by the absence of reliable biological markers for the disorder, as well as the reliability of screening and assessment tools for children aged between 6 and 18 months. Ongoing research has demonstrated the importance of early social communication skills in…

  20. Prediction models and risk assessment for silicosis using a retrospective cohort study among workers exposed to silica in China

    PubMed Central

    Tse, Lap Ah; Dai, Juncheng; Chen, Minghui; Liu, Yuewei; Zhang, Hao; Wong, Tze Wai; Leung, Chi Chiu; Kromhout, Hans; Meijer, Evert; Liu, Su; Wang, Feng; Yu, Ignatius Tak-sun; Shen, Hongbing; Chen, Weihong

    2015-01-01

    This study aims to develop a prognostic risk prediction model for the development of silicosis among workers exposed to silica dust in China. The prediction model was performed by using retrospective cohort of 3,492 workers exposed to silica in an iron ore, with 33 years of follow-up. We developed a risk score system using a linear combination of the predictors weighted by the LASSO penalized Cox regression coefficients. The model’s predictive accuracy was evaluated using time-dependent ROC curves. Six predictors were selected into the final prediction model (age at entry of the cohort, mean concentration of respirable silica, net years of dust exposure, smoking, illiteracy, and no. of jobs). We classified workers into three risk groups according to the quartile (Q1, Q3) of risk score; 203 (23.28%) incident silicosis cases were derived from the high risk group (risk score ≥ 5.91), whilst only 4 (0.46%) cases were from the low risk group (risk score < 3.97). The score system was regarded as accurate given the range of AUCs (83–96%). This study developed a unique score system with a good internal validity, which provides scientific guidance to the clinicians to identify high-risk workers, thus has important cost efficient implications. PMID:26090590

  1. 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.

  2. Toxicological evaluation of complex industrial wastes: Implications for exposure assessment

    SciTech Connect

    DeMarini, D.M.; Gallagher, J.E.; Houk, V.S.; Simmons, J.E.

    1990-07-01

    We evaluated a variety of short-term bioassays to construct a battery of tests that could be used for assessing the biological effects of potentially hazardous complex industrial wastes. Ten samples were studied for hepatotoxicity; these samples and an additional five were studied for mutagenicity. Although the data are limited to these samples, the results suggest that the Salmonella assay (strain TA98) or a prophage-induction assay (both in the presence of S9) in combination with determination of relative liver weight and levels of a set of serum enzymes in rats may provide a battery of tests suitable to characterize complex industrial wastes for mutagenic and hepatotoxic potential. The biological activities exhibited by the wastes were not readily predicted by the chemical profiles of the wastes, emphasizing the importance of characterizing potentially hazardous complex industrial wastes by both chemical and biological means. DNA from liver, lung, and bladder of rats exposed to some of the wastes was analyzed by the 32P-postlabeling technique for the presence of DNA adducts. A waste that produced mutagenic urine produced a DNA adduct in bladder DNA. The implications of this approach for assessment of exposure to complex hazardous waste mixtures are discussed.

  3. Exposure and risk assessment of zinc in Japanese surface waters.

    PubMed

    Naito, Wataru; Kamo, Masashi; Tsushima, Koji; Iwasaki, Yuichi

    2010-09-15

    In recent years, due to concerns on the potential effects of zinc on aquatic biota, zinc is receiving particular attention from regulatory agencies. A comprehensive exposure and risk assessment of zinc in Japanese surface waters was conducted to provide a scientific basis for developing realistic risk reduction measures for zinc. Emissions from corrosion contribute approximately 37% of the total zinc emissions to surface water in Japan. The zinc concentration distributions estimated using 12 years of monitoring data from 2075 sites by a maximum likelihood method indicated that the mean concentrations have gradually declined. The threshold concentrations (HC5 and PHC5) derived from organism- and population-level species sensitivity distributions were estimated to be 27 and 107 microg/L for total zinc, respectively. The risk characterization identified that during 1991-2002, 14.5-26.8% of the monitoring sites likely exceeded the HC5, whereas only 0.7-3.5% likely exceeded the PHC5. Evaluation of the effect of stormwater runoff to zinc concentrations in a river showed that zinc concentrations in river water increased significantly from roadway drainage flowing into the river. The cost-effectiveness analyses demonstrated that enforcement of the zinc national effluent standard may be effective at a certain level for public water areas in Japan; however, the degree of the effectiveness is highly dependent on the characteristics (e.g., sources and background) of the watersheds. An emissions and exposure assessment along with cost-effectiveness analysis is crucial for developing realistic and appropriate ecological risk management of zinc. The zinc RAD in Japan illustrated that in any "state-of-the science" method used, some degree of ecological risk from zinc can be observed in some Japanese water environments. On the other hand, zinc is a beneficial material for human industrial activities. Because zinc is an element, its role in industrial activities would be difficult

  4. A hazardous substance exposure prevention rating method for intervention needs assessment and effectiveness evaluation: the Small Business Exposure Index

    PubMed Central

    2009-01-01

    Aims This paper describes the refinement and adaptation to small business of a previously developed method for systematically prioritizing needs for intervention on hazardous substance exposures in manufacturing worksites, and evaluating intervention effectiveness. Methods We developed a checklist containing six unique sets of yes/no variables organized in a 2 × 3 matrix of exposure potential versus exposure protection at three levels corresponding to a simplified hierarchy of controls: materials, processes, and human interface. Each of the six sets of indicator variables was reduced to a high/moderate/low rating. Ratings from the matrix were then combined to generate an exposure prevention 'Small Business Exposure Index' (SBEI) Summary score for each area. Reflecting the hierarchy of controls, material factors were weighted highest, followed by process, and then human interface. The checklist administered by an industrial hygienist during walk-through inspection (N = 149 manufacturing processes/areas in 25 small to medium-sized manufacturing worksites). One area or process per manufacturing department was assessed and rated. A second hygienist independently assessed 36 areas to evaluate inter-rater reliability. Results The SBEI Summary scores indicated that exposures were well controlled in the majority of areas assessed (58% with rating of 1 or 2 on a 6-point scale), that there was some room for improvement in roughly one-third of areas (31% of areas rated 3 or 4), and that roughly 10% of the areas assessed were urgently in need of intervention (rated as 5 or 6). Inter-rater reliability of EP ratings was good to excellent (e.g., for SBEI Summary scores, weighted kappa = 0.73, 95% CI 0.52–0.93). Conclusion The SBEI exposure prevention rating method is suitable for use in small/medium enterprises, has good discriminatory power and reliability, offers an inexpensive method for intervention needs assessment and effectiveness evaluation, and complements

  5. 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...

  6. INNOVATIVE TOOLS AND METHODS FOR ASSESSING CHILDREN'S POTENTIAL CHEMICAL EXPOSURE

    EPA Science Inventory

    Children's exposures to environmental contaminants are different than adults, due in part to differences in physiologic functions. Research on children's exposure to environmental contaminants is currently being performed within EPA, academia, industry, and other research organi...

  7. 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...

  8. 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 ...

  9. Application of brown bear (Ursus arctos) records for retrospective assessment of mercury.

    PubMed

    Solgi, Eisa; Ghasempouri, Seyed Mahmoud

    2015-01-01

    Because mercury (Hg) is released into the atmosphere, wildlife living in habitats located far from point sources of metal may still be at risk. Mercury accumulation, previously considered a risk for aquatic ecosystems, is also found in many wildlife terrestrial species. The aim of the present study was to examine total Hg concentrations in the brown bear (Ursus arctos) by measurement of metal in hair from museum collections in Iran. Another objective of this investigation was to characterize the risk of Hg exposure in bears in several parts of Iran. Brown bear (Ursus arctos) hair samples (n = 35) were collected from 14 provinces in Iran for analysis of Hg contamination, performed using an advanced mercury analyzer (model Leco 254 AMA, USA) according to ASTM standard D-6722. Total Hg levels in Iranian bears from all areas ranged from 115.81 to 505.82 μg/kg, with a mean of 193.39 ng/g. Mercury concentrations in brown bear hair from different provinces in Iran were as follows in descending order: Khorasan Razavi > Esfahan > Khozestan > Yazd > Lorestan > Charmahalva Bakhtiari > Bushehr > Mazandaran > Markazi > Tehran > Ardebil > Gilan > East Azerbaijan. The highest content of Hg was found in the south (206.62 ± 31.95 ng/g), whereas the lowest levels were detected in the west (167.71 ± 32.97 ng/g). Overall total Hg content in bear hair was below harmful levels for this species. A decreasing trend was noted in the period 1986-2006, which may be mainly due to reduction of global Hg emissions. Data suggest that food habits and habitat are two important factors that influence Hg accumulation in bears. PMID:25734629

  10. 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...

  11. 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...

  12. Comparison of the Risk of Gastrointestinal Bleeding among Different Statin Exposures with Concomitant Administration of Warfarin: Electronic Health Record-Based Retrospective Cohort Study

    PubMed Central

    Lim, Sun Gyo; Hong, Ji Man; Park, Rae Woong; Lee, Jin Soo

    2016-01-01

    Background and Objective Patients who should be treated with both warfarin and a statin are frequently seen in vascular clinics. The risk for bleeding and potential drug interactions should be considered when prescribing both medications together. This study aimed to compare the risk for gastrointestinal bleeding among different statin exposures with concomitant administration of warfarin. Materials and Methods This is a single-hospital retrospective cohort study. We included patients who were concomitantly exposed to one of four statins (pravastatin, simvastatin, atorvastatin, and rosuvastatin) and warfarin for up to 2 years (730 days). The observation period ended when a gastrointestinal bleeding event occurred or the observation was censored. Within-class comparisons were used, and 1:1 matching using a propensity score was performed for comparisons between each statin and all of the other statins. Kaplan-Meier analyses with log-rank tests and Cox proportional hazard regression analyses were conducted to determine associations with the risk of gastrointestinal bleeding. Results Data were analyzed for 1,686 patients who were concomitantly administered a statin and warfarin. Log-rank tests for the gastrointestinal bleeding-free survival rate showed that the risk for gastrointestinal bleeding was significantly lower in the pravastatin group (p = 0.0499) and higher in the rosuvastatin group (p = 0.009). In the Cox proportional hazard regression analysis, the hazard ratio of 5.394 for gastrointestinal bleeding based on statin exposure in the rosuvastatin group was significant (95% confidence interval, 1.168–24.916). Conclusions There was a relatively high risk of gastrointestinal bleeding with rosuvastatin when administered concomitantly with warfarin. PMID:27386858

  13. Impact of the national venous thromboembolism risk assessment tool in secondary care in England: retrospective population-based database study.

    PubMed

    Catterick, David; Hunt, Beverly J

    2014-09-01

    Venous thromboembolism (VTE) is a common and important cause of death in hospital patients. We therefore investigated possible associations between the introduction of the compulsory national VTE risk assessment tool in England in 2010 and patient outcomes. A retrospective database study, using data from the Health and Social Care Information Centre and Office of National Statistics, was undertaken. The main outcome measures were VTE-related secondary diagnosis rates, 30-day and 90-day readmission rates and mortality rates. The observed mean VTE-related secondary diagnosis rate for 2011-2012 was 91% of the rate estimated from a linear regression model of the data for 2006-2007 to 2010-2011 (P = 0.001). Similarly, the observed mean 30-day VTE-related readmission rate for 2011 was 96% of the estimated rate (P = 0.067) and the observed mean 90-day VTE-related readmission rate for 2011 was 96% of the estimated rate (P = 0.022). The observed annual VTE-related national mortality rate was 91% of the estimated rate for 2011 and 92% of the estimated rate for 2012. This study shows a reduction in VTE-related secondary diagnoses and readmissions among adults admitted to hospital, and a reduction in VTE-related population mortality, since the introduction of a national VTE risk assessment screening tool in England. Despite some study limitations, this suggests that the concerted effort made by NHS England to improve prevention of hospital-acquired VTE has been successful.

  14. A Retrospective Study on Students' and Teachers' Perceptions of the Reflective Ability Clinical Assessment.

    PubMed

    Tsingos-Lucas, Cherie; Bosnic-Anticevich, Sinthia; Smith, Lorraine

    2016-08-25

    Objective. To evaluate student and teacher perceptions of the utility of the Reflective Ability Clinical Assessment (RACA) in an undergraduate pharmacy curriculum at an Australian university. Methods. A mixed-method study comprising the administration of a 7-item student survey on a 6-point Likert-type scale and a 45-minute focus group/phone interview with teachers. Results. Student (n=199) and teaching staff respondents (n=3) provided their perceptions of the implementation of the new educational tool. Student responses showed significant positive correlations between self-directed learning, counseling skills, relevance to future practice, and performance in an oral examination. Seven key themes emerged from the teacher interviews. Conclusion. The study revealed both students and teachers perceive the RACA as an effective educational tool that may enhance skill development for future clinical practice. PMID:27667838

  15. A Retrospective Study on Students’ and Teachers’ Perceptions of the Reflective Ability Clinical Assessment

    PubMed Central

    Bosnic-Anticevich, Sinthia; Smith, Lorraine

    2016-01-01

    Objective. To evaluate student and teacher perceptions of the utility of the Reflective Ability Clinical Assessment (RACA) in an undergraduate pharmacy curriculum at an Australian university. Methods. A mixed-method study comprising the administration of a 7-item student survey on a 6-point Likert-type scale and a 45-minute focus group/phone interview with teachers. Results. Student (n=199) and teaching staff respondents (n=3) provided their perceptions of the implementation of the new educational tool. Student responses showed significant positive correlations between self-directed learning, counseling skills, relevance to future practice, and performance in an oral examination. Seven key themes emerged from the teacher interviews. Conclusion. The study revealed both students and teachers perceive the RACA as an effective educational tool that may enhance skill development for future clinical practice. PMID:27667838

  16. A Retrospective Study on Students’ and Teachers’ Perceptions of the Reflective Ability Clinical Assessment

    PubMed Central

    Bosnic-Anticevich, Sinthia; Smith, Lorraine

    2016-01-01

    Objective. To evaluate student and teacher perceptions of the utility of the Reflective Ability Clinical Assessment (RACA) in an undergraduate pharmacy curriculum at an Australian university. Methods. A mixed-method study comprising the administration of a 7-item student survey on a 6-point Likert-type scale and a 45-minute focus group/phone interview with teachers. Results. Student (n=199) and teaching staff respondents (n=3) provided their perceptions of the implementation of the new educational tool. Student responses showed significant positive correlations between self-directed learning, counseling skills, relevance to future practice, and performance in an oral examination. Seven key themes emerged from the teacher interviews. Conclusion. The study revealed both students and teachers perceive the RACA as an effective educational tool that may enhance skill development for future clinical practice.

  17. A retrospective study to assess resource utilization in patients with cervical dystonia in the United Kingdom

    PubMed Central

    Raluy-Callado, Mireia; Gabriel, Sylvie; Dinet, Jérôme; Wang, Meng; Wasiak, Radek

    2015-01-01

    Purpose Cervical dystonia (CD) is a hypertonic condition caused by damage to the central nervous system. Very few studies have assessed the overall economic burden of the disease. The objective of this study was to describe the utilization of health care resources of patients with CD in the UK primary care setting, using a large population-based database. Patients and methods Adults with a first diagnosis of CD between January 1, 2007 and January 31, 2011, who were registered to a general practitioner (GP) practice contributing to The Health Improvement Network (THIN), were included. Sociodemographic and clinical characteristics were assessed at the time of diagnosis. Health care resource utilization and pharmacological treatment were investigated at the end of the first and second year after diagnosis. Results Overall, 4,024 newly diagnosed patients with CD were identified, with average age at diagnosis of 45 years old; 65.3% were female. Depression in the year prior to diagnosis was the most common comorbidity. Primary care utilization was high in the first year, with 99.2% of patients visiting their GP (on average 6.2 times), and 43% visiting a nurse (on average 2.5 times). Patients were most commonly referred to an orthopedic surgeon, and 15.9% reported at least one physiotherapy visit. In the second year, utilization was similar. Prescriptions of at least one of the investigated treatments were found in 82.0% and 45.3%, in the first and second year, respectively. Conclusion Findings suggest a high number of new CD cases are being identified in primary care, but not all will be referred to secondary care. Health care resource utilization was compared with that of all patients registered in THIN, which is representative of the UK, and the adjusted usage of primary care resources was found to be similar to that of the THIN population. PMID:25834443

  18. 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

  19. Methods for assessing the stability of slopes during earthquakes-A retrospective

    USGS Publications Warehouse

    Jibson, R.W.

    2011-01-01

    During the twentieth century, several methods to assess the stability of slopes during earthquakes were developed. Pseudostatic analysis was the earliest method; it involved simply adding a permanent body force representing the earthquake shaking to a static limit-equilibrium analysis. Stress-deformation analysis, a later development, involved much more complex modeling of slopes using a mesh in which the internal stresses and strains within elements are computed based on the applied external loads, including gravity and seismic loads. Stress-deformation analysis provided the most realistic model of slope behavior, but it is very complex and requires a high density of high-quality soil-property data as well as an accurate model of soil behavior. In 1965, Newmark developed a method that effectively bridges the gap between these two types of analysis. His sliding-block model is easy to apply and provides a useful index of co-seismic slope performance. Subsequent modifications to sliding-block analysis have made it applicable to a wider range of landslide types. Sliding-block analysis provides perhaps the greatest utility of all the types of analysis. It is far easier to apply than stress-deformation analysis, and it yields much more useful information than does pseudostatic analysis. ?? 2010.

  20. International Symposia on Integrated Exposure Assessment for Hazardous Materials

    PubMed Central

    Kwon, Ho-Jang; Ha, Mina

    2012-01-01

    Objectives On September 2, 2010 and November 25, 2011, the Korean Research Project on Integrated Exposure Assessment to Hazardous Materials for Food Safety (KRIEFS) organized two international symposia in Seoul, Korea. KRIEFS, established by the Korean Food and Drug Administration in March 2010, envisioned these international symposia as means to obtain advanced experiences from other countries and to reflect on and refine the KRIEFS's survey design and methods. Methods For the first symposium KRIEFS invited human biomonitoring (HBM) experts from Germany, the US, and Canada. The visiting HBM experts shared the details of their national studies while the KRIEFS discussed study design, as well as the methods, results and policymaking processes of the KRIEFS project. The second symposium was organized to share the survey design and results on endocrine disruptors from Taiwan. Results The Speaker from Germany introduced the German Environmental Survey and shared their experiences in HBM design, such as the process of developing reference values, and discussed the new HBM plan in Germany and the European Union. The Representative from Canada shared insights from national HBM approach. In the case of the US, the speaker focused on risk communication with subjects in epidemiological studies. In the second international symposium, the speaker shared the experience of endocrine disruptors'studies from Taiwan. Conclusions KRIEFS was able to better understand previous nationwide HBM research designs, policy making process, and risk communication with research subjects.

  1. Physiologic assessment of fetal compromise: biomarkers of toxic exposure

    SciTech Connect

    Longo, L.D.

    1987-10-01

    Understanding the physiologic and endocrinologic basis of fetal development is a major goal of perinatal biology. During the past decade a number of technological developments have allowed more precise evaluation of the fetus in utero and diagnosis of abnormalities. Despite these methodological achievements, however, there are no specific biological markers currently available to indicate that exposure to a given xenobiotic is associated with a cellular, subcellular, or pharmacodynamic event. This paper evaluates the following issues: what are some of the unique physiologic and endocrinologic features of the fetal milieu interieur. What problems are peculiar to fetal assessment. What are some examples of validated biomarkers and their applicability. What promising biomarkers are on the horizon. How may molecular probes be of value as biological markers of fetal compromise. What are some of the major research gaps and needs, and how should research priorities be set. Some of these topics are addressed. Moreover, the more general role(s) that various diagnostic methods and biological markers can have in an understanding of the regulation of fetal growth and differentiation and the role of xenobiotics in affecting the normal course of events are discussed.

  2. Assessing host extinction risk following exposure to Batrachochytrium dendrobatidis.

    PubMed

    Louca, Stilianos; Lampo, Margarita; Doebeli, Michael

    2014-06-22

    Wildlife diseases are increasingly recognized as a major threat to biodiversity. Chytridiomycosis is an emerging infectious disease of amphibians caused by the fungus Batrachochytrium dendrobatidis (Bd). Using a mathematical model and simulations, we study its effects on a generic riparian host population with a tadpole and adult life stage. An analytical expression for the basic reproduction quotient, Qo, of the pathogen is derived. By sampling the entire relevant parameter space, we perform a statistical assessment of the importance of all considered parameters in determining the risk of host extinction, upon exposure to Bd. We find that Qo not only gives a condition for the initial invasion of the fungus, but is in fact the best predictor for host extinction. We also show that the role of tadpoles, which in some species tolerate infections, is ambivalent. While tolerant tadpoles may provide a reservoir for the fungus, thus facilitating its persistence or even amplifying its outbreaks, they can also act as a rescue buffer for a stressed host population. Our results have important implications for amphibian conservation efforts.

  3. Assessing host extinction risk following exposure to Batrachochytrium dendrobatidis

    PubMed Central

    Louca, Stilianos; Lampo, Margarita; Doebeli, Michael

    2014-01-01

    Wildlife diseases are increasingly recognized as a major threat to biodiversity. Chytridiomycosis is an emerging infectious disease of amphibians caused by the fungus Batrachochytrium dendrobatidis (Bd). Using a mathematical model and simulations, we study its effects on a generic riparian host population with a tadpole and adult life stage. An analytical expression for the basic reproduction quotient, Qo, of the pathogen is derived. By sampling the entire relevant parameter space, we perform a statistical assessment of the importance of all considered parameters in determining the risk of host extinction, upon exposure to Bd. We find that Qo not only gives a condition for the initial invasion of the fungus, but is in fact the best predictor for host extinction. We also show that the role of tadpoles, which in some species tolerate infections, is ambivalent. While tolerant tadpoles may provide a reservoir for the fungus, thus facilitating its persistence or even amplifying its outbreaks, they can also act as a rescue buffer for a stressed host population. Our results have important implications for amphibian conservation efforts. PMID:24807247

  4. 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.

  5. 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

  6. 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...

  7. Review of methods applicable to the assessment of mold exposure to children.

    PubMed Central

    Dillon, H K; Miller, J D; Sorenson, W G; Douwes, J; Jacobs, R R

    1999-01-01

    This article presents discussion of the assessment of the exposure of children to fungi, substances derived from fungi, and the environmental conditions that may lead to exposure. The principles driving investigations of fungal contamination and subsequent exposure are presented as well as guidelines for conducting these investigations. A comprehensive description of available research sampling and analysis techniques is also presented. PMID:10423390

  8. Retrospective assessment of personnel neutron dosimetry for workers at the Hanford Site

    SciTech Connect

    Fix, J.J.; Wilson, R.H.; Baumgartner, W.B.

    1996-09-01

    This report was prepared to examine the specific issue of the potential for unrecorded neutron dose for Hanford workers, particularly in comparison with the recorded whole body (neutron plus photon) dose. During the past several years, historical personnel dosimetry practices at Hanford have been documented in several technical reports. This documentation provides a detailed history of the technology, radiation fields, and administrative practices used to measure and record dose for Hanford workers. Importantly, documentation has been prepared by personnel whose collective experience spans nearly the entire history of Hanford operations beginning in the mid-1940s. Evaluations of selected Hanford radiation dose records have been conducted along with statistical profiles of the recorded dose data. The history of Hanford personnel dosimetry is complex, spanning substantial evolution in radiation protection technology, concepts, and standards. Epidemiologic assessments of Hanford worker mortality and radiation dose data were initiated in the early 1960s. In recent years, Hanford data have been included in combined analyses of worker cohorts from several Department of Energy (DOE) sites and from several countries through the International Agency for Research on Cancer (IARC). Hanford data have also been included in the DOE Comprehensive Epidemiologic Data Resource (CEDR). In the analysis of Hanford, and other site data, the question of comparability of recorded dose through time and across the respective sites has arisen. DOE formed a dosimetry working group composed of dosimetrists and epidemiologists to evaluate data and documentation requirements of CEDR. This working group included in its recommendations the high priority for documentation of site-specific radiation dosimetry practices used to measure and record worker dose by the respective DOE sites.

  9. Assessment of providers' referral decisions in Rural Burkina Faso: a retrospective analysis of medical records

    PubMed Central

    2012-01-01

    Background A well-functioning referral system is fundamental to primary health care delivery. Understanding the providers' referral decision-making process becomes critical. This study's aim was to assess the correctness of diagnoses and appropriateness of the providers' referral decisions from health centers (HCs) to district hospitals (DHs) among patients with severe malaria and pneumonia. Methods A record review of twelve months of consultations was conducted covering eight randomly selected HCs to identify severe malaria (SM) cases among children under five and pneumonia cases among adults. The correctness of the diagnosis and appropriateness of providers' referral decisions were determined using the National Clinical Guidebook as a 'gold standard'. Results Among the 457 SM cases affecting children under five, only 66 cases (14.4%) were correctly diagnosed and of those 66 correctly diagnosed cases, 40 cases (60.6%) received an appropriate referral decision from their providers. Within these 66 correctly diagnosed SM cases, only 60.6% were appropriately referred. Among the adult pneumonia cases, 5.9% (79/1331) of the diagnoses were correctly diagnosed; however, the appropriateness rate of the provider's referral decision was 98.7% (78/79). There was only one case that should not have been referred but was referred. Conclusions The adherence to the National Guidelines among the health center providers when making a diagnosis was low for both severe malaria cases and pneumonia cases. The appropriateness of the referral decisions was particularly poor for children with severe malaria. Health center providers need to be better trained in the diagnostic process and in disease management in order to improve the performance of the referral system in rural Burkina Faso. PMID:22397326

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

    PubMed

    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

  11. 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

  12. Contrast Circulation Time to Assess Right Ventricular Dysfunction in Pulmonary Embolism: A Retrospective Pilot Study

    PubMed Central

    Platon, Alexandra; Poletti, Pierre-Alexandre; Perrier, Arnaud; Bendjelid, Karim

    2016-01-01

    Objective To optimize enhancement of pulmonary arteries and facilitate diagnosis of pulmonary embolism (PE), modern computed tomography angiography (CTA) contains a contrast bolus tracking system. We explored the diagnostic accuracy of the time-intensity curves given by this automated system to identify right ventricular dysfunction (RVD) in acute PE. Methods 114 CTAs with a diagnosis of PE were reviewed. RVD was defined as right-to-left ventricular diameter ratio of 1 or greater. Four parameters on time-intensity curves were identified. Parameters between CTAs with and those without RVD were compared with the Wilcoxon rank-sum test. The ability of the four parameters to discriminate patients with RVD was explored by compiling the area under the operating curves (AUC). Results The time needed by the contrast media to reach the pulmonary artery [8 seconds (IQR: 7–9) versus 7 seconds (IQR: 6–8), p<0.01], the time needed to reach 40 Hounsfield units (HU) [11 seconds (IQR: 8.5–14) versus 9.5 seconds (IQR: 8–10.5), p<0.01], and the contrast intensity reached after 10 seconds [19 HU (IQR: 4–67) versus 53 HU (IQR: 32–80), p<0.05] were all statistically different between CTA with and CTA without RVD. Those three parameters changed gradually across severity categories of RVD (p<0.05 for trend). Their AUC to identify RVD ranged from 0.63 to 0.66. The slope of contrast intensity over time was not informative: [31 HU/s (IQR: 20–57) in CTA with, compared to 36 HU/s (IQR: 22.5–53) in CTA without RVD, p = 0.60]. Conclusion Several parameters of the time-intensity curve obtained by the bolus tracking system are associated with RVD assessed on CTA images. Of those, the time needed to reach a predefined threshold seems to be the easiest to obtain in any CTA without additional processing time or contrast injection. However, the performance of those parameters is globally low. PMID:27551831

  13. Assessment of multipathway exposure of small children to PAH.

    PubMed

    Vyskocil; Fiala; Chénier; Krajak; Ettlerova; Bukac; Viau; Emminger

    2000-01-01

    The aim of study was to assess the uptake of polycyclic aromatic hydrocarbons (PAH) by children living in a city and its effect on 1-hydroxypyrene (1-OHP) excretion. Two groups of children (n=11 and 13; 3-6 years old) were chosen: (1) a group from a kindergarten situated near a road with a high traffic density ('polluted' area); (2) a group from a kindergarten situated in a green zone ('non polluted' area). Food consumption was recorded in all children and PAH uptake from foodstuffs was estimated. Ambient air samples were collected on the playground and indoor of kindergartens during 3 days in summer 1997. Soil samples were collected on the playground. Urine samples were collected in the morning and in the evening. Mean outdoor total PAH concentration (sum of 12 individual PAH) in 'polluted' area was 12 times higher than that in 'non polluted' area (22.9 vs. 1.9 ng/m(3)). However, indoor concentrations were similar (3.0 vs. 2.1 ng/m(3)). The same trend was observed for pyrene concentrations. The contribution to the total pyrene absorbed dose from food consumption (estimated daily absorbed dose of 167 and 186 ng, respectively, in 'polluted' and 'non polluted' area) was much more important than that from inhalation (8.4 and 5.4 ng, respectively) in both areas. The estimated daily absorbed doses of pyrene from the soil were 0.061 and 0.104 ng in 'polluted' and 'non polluted' kindergarten, respectively, which correspond to 0.032 and 0.059% of the total absorbed dose. Higher urinary concentrations of 1-OHP were found in children from 'polluted' kindergarten. In conclusion, the food seems to be a main source of the total pyrene and total PAH uptake in small children, even under a relative high PAH air exposure in the city. Pyrene concentration in soil had a negligible contribution to the total pyrene absorbed dose. Usefulness of the urinary 1-OHP as an indicator of the environmental exposure to PAH needs further research.

  14. 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...

  15. Reliability of Questionnaire Data in the Distant Past: Relevance for Radiation Exposure Assessment.

    PubMed

    Drozdovitch, Vladimir; Kukhta, Tatiana; Minenko, Victor; Trofimik, Sergey; Bouville, André; Potischman, Nancy

    2016-01-01

    Interviews with questionnaires are often employed to provide information that may be used for exposure assessment, although the reliability of such information is largely unknown. In this work, the consistency of individual behavior and dietary data collected by means of personal interviews during two study screenings was evaluated. Data were collected for a cohort of about 11,000 persons exposed to 131I in childhood and adolescence shortly after the Chernobyl accident. The best recollection was found for residential history, milk consumption patterns, and, to a lesser degree, stable iodine administration, while reproducibility of responses about consumption of milk products and leafy vegetables was poor. Consistency of information reported during the personal interviews by the study subjects younger than 10 y at the time of the accident was somewhat lower than for the subjects aged 10-18 y. The authors found slightly better reproducibility of responses for female study subjects than for male subjects and when the time span between two interviews was shorter. In the majority of instances, the best consistency in responses was observed when the mother was interviewed during both screenings rather than the subject. Information that was collected during two personal interviews was used to calculate two sets of thyroid doses due to 131I intakes. This study shows that, because dose-related measurements are available for all study subjects, the quality of individual behavior and dietary data has, in general, a small influence on the results of the retrospective dose assessment. For studies in which dose-related measurements are not available for all study subjects and only modeling is used for dose reconstruction, high quality individual behavior and dietary data for the study subjects are required to provide realistic and reliable dose estimates.

  16. 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.

  17. A Retrospective Observational Study to Assess Prescription Pattern in Patients with Type B Aortic Dissection and Treatment Outcome

    PubMed Central

    Wang, Shih-Han; Huang, Jiann-Woei

    2016-01-01

    Aortic dissection is a life-threatening condition. However, the use of medication to treat it remains unclear in our population, particularly in patients with a type B aortic dissection (TBAD) who do not receive surgery. This retrospective cohort study evaluated antihypertensive prescription patterns and outcomes in patients with nonsurgical TBAD. We reviewed the hospital records of patients with TBAD at a medical center in Taiwan from January 2008 to June 2013 to assess the baseline information, prescribing pattern, event rate, and clinical effectiveness of different antihypertensive treatment strategies. A Cox proportional hazards model was used to estimate outcomes in different antihypertensive strategies. The primary endpoints were all-cause mortality and hospital admission for an aortic dissection. We included 106 patients with a mean follow-up period of 2.75 years. The most common comorbidity was hypertension followed by dyslipidemia and diabetes mellitus. Study endpoints mostly occurred within 6 months after the index date. Over 80% of patients received dual or triple antihypertensive strategies. Patients treated with different treatment strategies did not have a significantly increased risk of a primary outcome compared with those treated with a monotherapy. We found no significant difference in the primary outcome following the use of different antihypertensive medication regimes. PMID:27563668

  18. Assessing clinical outcomes of patients with acute calculous cholecystitis in addition to the Tokyo grading: a retrospective study.

    PubMed

    Cheng, Wei-Chun; Chiu, Yen-Cheng; Chuang, Chiao-Hsiung; Chen, Chiung-Yu

    2014-09-01

    The management of acute cholecystitis is still based on clinical expertise. This study aims to investigate whether the outcome of acute cholecystitis can be related to the severity criteria of the Tokyo guidelines and additional clinical comorbidities. A total of 103 patients with acute cholecystitis were retrospectively enrolled and their medical records were reviewed. They were all classified according to therapeutic modality, including early cholecystectomy and antibiotic treatment with or without percutaneous cholecystostomy. The impact of the Tokyo guidelines and the presence of comorbidities on clinical outcome were assessed by univariate and multivariate regression analyses. According to Tokyo severity grading, 48 patients were Grade I, 31 patients were Grade II, and 24 patients were Grade III. The Grade III patients had a longer hospital stay than Grade II and Grade I patients (15.2 days, 9.2 days, and 7.3 days, respectively, p < 0.05). According to multivariate analysis, patients with Grade III Tokyo severity, higher Charlson's Comorbidity Score, and encountering complications had a longer hospital stay. Based on treatment modality, surgeons selected the patients with less severity and fewer comorbidities for cholecystectomy, and these patients had a shorter hospital stay. In addition to the grading of the Tokyo guidelines, comorbidities had an additional impact on clinical outcomes and should be an important consideration when making therapeutic decisions.

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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…

  5. EMF exposure assessment in the Finnish garment industry: evaluation of proposed EMF exposure metrics.

    PubMed

    Hansen, N H; Sobel, E; Davanipour, Z; Gillette, L M; Niiranen, J; Wilson, B W

    2000-01-01

    Recently published studies indicate that having worked in occupations that involve moderate to high electromagnetic field (EMF) exposure is a risk factor for neurodegenerative diseases, including Alzheimer's disease. In these studies, the occupational groups most over-represented for EMF exposure comprised seamstresses, dressmakers, and tailors. Future epidemiologic studies designed to evaluate the possibility of a causal relationship between exposure to EMF and a neuro degenerative disease endpoint such as incidence of Alzheimer's disease, will benefit from the measurement of electromagnetic field metrics with potential biological relevance. Data collection methodology in such studies would be highly dependent upon how the metrics are defined. In this research the authors developed and demonstrated (1) protocols for collecting EMF exposure data suitable for estimating a variety of exposure metrics that may have biological relevance, and (2) analytical methods for calculation of these metrics. The authors show how exposure might be estimated under each of the three prominent EMF health-effects mechanism theories and evaluate the assertion that relative exposure ranking is dependent on which mechanism is assumed. The authors also performed AC RMS magnetic flux density measurements, confirming previously reported findings. The results indicate that seamstresses, as an occupational group, should be considered for study of the possible health effects of long-term EMF exposure.

  6. 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.

  7. Fabrication of vertical nanowire resonators for aerosol exposure assessment

    NASA Astrophysics Data System (ADS)

    Merzsch, Stephan; Wasisto, Hutomo Suryo; Stranz, Andrej; Hinze, Peter; Weimann, Thomas; Peiner, Erwin; Waag, Andreas

    2013-05-01

    Vertical silicon nanowire (SiNW) resonators are designed and fabricated in order to assess exposure to aerosol nanoparticles (NPs). To realize SiNW arrays, nanolithography and inductively coupled plasma (ICP) deep reactive ion etching (DRIE) at cryogenic temperature are utilized in a top-down fabrication of SiNW arrays which have high aspect ratios (i.e., up to 34). For nanolithography process, a resist film thickness of 350 nm is applied in a vacuum contact mode to serve as a mask. A pattern including various diameters and distances for creating pillars is used (i.e., 400 nm up to 5 μm). In dry etching process, the etch rate is set high of 1.5 μm/min to avoid underetching. The etch profiles of Si wires can be controlled aiming to have either perpendicularly, negatively or positively profiled sidewalls by adjusting the etching parameters (e.g., temperature and oxygen content). Moreover, to further miniaturize the wire, multiple sacrificial thermal oxidations and subsequent oxide stripping are used yielding SiNW arrays of 650 nm in diameter and 40 μm in length. In the resonant frequency test, a piezoelectric shear actuator is integrated with the SiNWs inside a scanning electron microscope (SEM) chamber. The observation of the SiNW deflections are performed and viewed from the topside of the SiNWs to reduce the measurement redundancy. Having a high deflection of ~10 μm during its resonant frequency of 452 kHz and a low mass of 31 pg, the proposed SiNW is potential for assisting the development of a portable aerosol resonant sensor.

  8. Baleen hormones: a novel tool for retrospective assessment of stress and reproduction in bowhead whales (Balaena mysticetus)

    PubMed Central

    Hunt, Kathleen E.; Stimmelmayr, Raphaela; George, Craig; Hanns, Cyd; Suydam, Robert; Brower, Harry; Rolland, Rosalind M.

    2014-01-01

    Arctic marine mammals are facing increasing levels of many anthropogenic stressors. Novel tools are needed for assessment of stress physiology and potential impacts of these stressors on health, reproduction and survival. We have investigated baleen as a possible novel tissue type for retrospective assessment of stress and reproductive hormones. We found that pulverized baleen powder from bowhead whales (Balaena mysticetus) contained immunoreactive cortisol and progesterone that were detectable with commercially available enzyme immunoassay kits. Both assays passed parallelism and accuracy validations using baleen extracts. We analysed cortisol and progesterone at the base of the baleen plate (most recently grown baleen) from 16 bowhead whales of both sexes. For a subset of 11 whales, we also analysed older baleen from 10, 20 and 30 cm distal to the base of the baleen plate. Immunoreactive cortisol and progesterone were detectable in all baleen samples tested. In base samples, females had significantly higher concentrations of cortisol and progesterone compared with males. Cortisol concentrations in older baleen (10, 20 and 30 cm locations) were significantly lower than at the base and did not exhibit correlations with age-class or sex. Progesterone concentrations were significantly higher in females than in males at all baleen locations tested and were significantly higher in pregnant females than in non-pregnant females. Four of five mature females showed dramatic variation in progesterone concentrations at different locations along the baleen plate that may be indicative of previous pregnancies or luteal phases. In contrast, all males and all immature females had uniformly low progesterone. Baleen hormone analysis is a novel approach that, with further methodological development, may be useful for determining individual longitudinal profiles of reproductive cycles and stress responses. PMID:27293651

  9. Design strategy for assessing multi-pathway exposure for children: the Minnesota Children's Pesticide Exposure Study (MNCPES).

    PubMed

    Quackenboss, J J; Pellizzari, E D; Shubat, P; Whitmore, R W; Adgate, J L; Thomas, K W; Freeman, N C; Stroebel, C; Lioy, P J; Clayton, A C; Sexton, K

    2000-01-01

    Although children are exposed to a variety of environmental hazards, including pesticides, there is a scarcity of information available to estimate exposures realistically. This article reports on one of the first attempts to measure multi-pathway pesticide exposures in a population-based sample of urban and non-urban children. A design strategy was developed to assess multi-pathway pesticide exposures in children using personal exposure measurements in combination with complimentary measurements of biological markers of exposure, concentrations in relevant environmental media, and time spent in important microenvironments and participating in exposure-related activities. Sample collection and analysis emphasized measurement of three insecticides (i.e., chlorpyrifos, diazinon, and malathion) and one herbicide (i.e., atrazine). These compounds were selected because of their frequent use, presence in multiple environmental media, expected population exposures, and related hazard/toxicity. The study was conducted during the summer of 1997 in Minnesota and involved a stratified sample of households with children ages 3-12 years. Participants resided in either (a) the cities of Minneapolis and St. Paul (urban households), or (b) Rice and Goodhue Counties just south of the metropolitan area (non-urban households). Results from a residential inventory documenting storage and use of products containing the target pesticides were used to preferentially select households where children were likely to have higher exposures. The study successfully obtained pesticide exposure data for 102 children, including measurements of personal exposures (air, hand rinse, duplicate diet), environmental concentrations (residential indoor/outdoor air, drinking water, residential surfaces, soil), activity patterns (obtained by questionnaire, diary, videotaping), and internal dose (metabolites in urine).

  10. Sulfuric acid aerosol exposure in humans assessed by bronchoalveolar lavage

    SciTech Connect

    Frampton, M.W.; Voter, K.Z.; Morrow, P.E.; Roberts, N.J. Jr.; Culp, D.J.; Cox, C.; Utell, M.J. )

    1992-09-01

    Epidemiologic and experimental evidence suggests that exposure to acidic aerosols may affect human health. Brief exposures to acidic aerosols alter mucociliary clearance and increase airway responsiveness, but effects on host defense mechanisms at the alveolar level have not been studied in humans. Twelve healthy, nonsmoking volunteers between 20 and 39 yr of age were exposed for 2 h to aerosols of approximately 1,000 micrograms/m3 sulfuric acid (H2SO4) or sodium chloride (NaCl (control)), with intermittent exercise, in a randomized, double-blind fashion. Each subject received both exposures, separated by at least 2 wk. Bronchoalveolar lavage (BAL) was performed 18 h after exposure in order to detect evidence of an inflammatory response, changes in alveolar cell subpopulations, or changes in alveolar macrophage (AM) function, which is important in host defense. When compared with NaCl, exposure to H2SO4 did not increase polymorphonuclear leukocytes in BAL fluid. The percentage of T lymphocytes decreased in association with H2SO4 exposure, but the difference was not statistically significant (14.9% after NaCl, 11.5% after H2SO4; p = 0.14). Antibody-mediated cytotoxicity of AM increased in association with H2SO4 exposure (percent lysis 19.1 after NaCl, 23.6 after H2SO4; p = 0.16). No significant change was seen in release of superoxide anion or inactivation of influenza virus in vitro. Brief exposures to H2SO4 aerosol at 1,000 micrograms/m3 do not cause an influx of inflammatory cells into the alveolar space, and no evidence was found for alteration in antimicrobial defense 18 h after exposure.

  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. PMID:27255804

  12. Exposure assessment and risk characterization for perfluorooctanoate in selected consumer articles.

    PubMed

    Washburn, Stephen T; Bingman, Timothy S; Braithwaite, Scott K; Buck, Robert C; Buxton, L William; Clewell, Harvey J; Haroun, Lynne A; Kester, Janet E; Rickard, Robert W; Shipp, Annette M

    2005-06-01

    An exposure assessment and risk characterization was conducted to better understand the potential human health significance of trace levels of perfluorooctanoate (PFO) detected in certain consumer articles. PFO is the anion of perfluorooctanoic acid (PFOA). Concentrations of PFO in the consumer articles were determined from extraction tests and product formulation information. Potential exposures during consumer use of the articles were quantified based on an assessment of behavior patterns and regulatory guidance. Health benchmarks were developed and then compared to the exposure estimates to yield margins of exposure (MOEs). A simple one-compartment model was also developed to estimate contributions of potential consumer exposures to PFO concentrations in serum. While there are considerable uncertainties in this assessment, it indicates that exposures to PFO during consumer use of the articles evaluated in this study are not expected to cause adverse human health effects in infants, children, adolescents, adult residents, or professionals nor result in quantifiable levels of PFO in human serum.

  13. 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...

  14. Exposure assessment to glyphosate of two species of annelids.

    PubMed

    García-Torres, Tristán; Giuffré, Lidia; Romaniuk, Romina; Ríos, Ruth P; Pagano, Eduardo A

    2014-08-01

    Adult mortality, biomass, fecundity and viability of cocoons were studied in Eisenia fetida and Octolasion tyrtaeum, in response to glyphosate exposure in soil. Exposure tests were carried out following USEPA procedure, with five concentrations of glyphosate in soil and a control. O. tyrtaeum was more sensitive to the highest concentration of glyphosate (50,000 mg kg(-1)), with 100 % mortality by day 7 of exposure, compared with 71 % for E. fetida. Although biomass of O. tyrtaeum was significantly different between the control and 5,000 mg kg(-1) dose at day 14, E. fetida was not affected at that concentration, and only showed a significant weight loss after 7 days of exposure to 50,000 mg kg(-1). Adverse effects upon adult fecundity and cocoon viability were observed at glyphosate concentrations of 5,000 mg kg(-1) and above. Adverse effects were observed at concentrations that greatly exceeded the recommended field application rates of glyphosate.

  15. 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.

  16. ENVIRONMENTAL MONITORING AND HUMAN EXPOSURE ASSESSMENT USING IMMUNOCHEMICAL TECHNIQUES

    EPA Science Inventory

    The use of immunochemical technologies including, but not limited to, immunoassays is expanding to include various aspects of environmental analysis. Ultimately, the basis for environmental investigations is concern about human and ecological exposure to potentially toxic compoun...

  17. The practice of exposure assessment: a state-of-the-art review.

    PubMed

    Paustenbach, D J

    2000-01-01

    Each of us encounters hundreds of toxic agents everyday, without exposure and subsequent absorption (uptake) however, there is no risk of injury. Thus, exposure assessment is one of the three legs of the stool (along with toxicity assessment and dose-response assessment) upon which the practice of risk assessment rests. The field of exposure assessment has evolved out of at least 3 other disciplines over the past 50 years, including health physics, industrial hygiene, and epidemiology. Exposure assessments are a necessary component to understanding the hazard posed by exposure to naturally (e.g., aflatoxins in foods, radon in air) and nonnaturally occurring toxicants (e.g., benzene in groundwater, MTBE in air, and food additives). This article presents a thorough review of the field, including a discussion of the terminology used in exposure assessment, a description of how to quantitatively estimate dose for the major sources of exposure (food, water, air, and soil), and many of the best sources of information. In addition, techniques for assessing both variability and uncertainty are presented. Lessons learned over the past twenty years are emphasized. Some example calculations are included, nearly 400 references are cited, and a glossary of terms is provided.

  18. Reliable exposure assessment strategies for physical ergonomics stressors in construction and other non-routinized work.

    PubMed

    Paquet, Victor; Punnett, Laura; Woskie, Susan; Buchholz, Bryan

    2005-07-15

    The objective of this research was to provide guidelines for the reliable assessment of ergonomics exposures in non-routinized work. Using a discrete-interval observational sampling approach, two or three observers collected a total of 5852 observations on tasks performed by three construction trades (iron workers, carpenters and labourers) for periods of several weeks. For each observation, nine exposure variables associated with awkward body postures, tool use and load handling were recorded. The frequency of exposure to each variable was calculated for each worker during each of the tasks on each of the days. ANOVA was used to assess the importance of task in explaining between-worker and within-worker variability in exposures across days. A statistical re-sampling method (bootstrap) was used to evaluate the reliability of exposure estimates for groups of workers performing the same task for different sampling periods. Most exposures were found to vary significantly across construction tasks within trade, and between-worker exposure variability was generally smaller than within-worker exposure variability within task. Bootstrapping showed that the reliability of the group estimates exposure for the most variable exposures within task tended to improve as the assessment periods approached 5-6 d, with marginal improvements for longer assessment periods. Reliable group estimates of exposure for the least variable exposures within task were obtained with 1 or 2 d of observation. The results of this study demonstrate that an initial estimate of the important environmental or task sources of exposure variability can be used to develop an efficient sampling strategy that provides reliable estimates of ergonomics exposures during non-routinized work.

  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. Use of retrospective data to assess ecotoxicological monitoring needs for terrestrial vertebrates residing in Atlantic coast estuaries

    USGS Publications Warehouse

    Cohen, J.B.; Rattner, B.A.; Golden, N.H.

    2003-01-01

    The 'Contaminant Exposure and Effects--Terrestrial Vertebrates' (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n=2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The U.S. Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.

  1. Assessing herd immunity against rubella in Japan: a retrospective seroepidemiological analysis of age-dependent transmission dynamics

    PubMed Central

    Kinoshita, Ryo; Nishiura, Hiroshi

    2016-01-01

    Objective We aimed to epidemiologically assess rubella herd immunity as a function of time, age and gender in Japan, with reference to the recent 2012–2014 rubella epidemic. Design This study is a retrospective seroepidemiological analysis. Main outcome measures The susceptible fraction of the population was examined as a function of age and time. The age at infection was assessed using reported case data. Results Whereas 30 years ago rubella cases were seen only among children, the median (25–75th centiles) age of cases in 2014 was elevated to 32.0 (17.0–42.0) years among males and 27.0 (7.0–37.0) years among females. Susceptible pockets among male birth cohorts 1989–1993 and 1974–1978 were identified, with seropositive proportions of 70.0% and 68.0%, respectively. The majority of female age groups had greater seropositive proportions than the herd immunity threshold, with a minor susceptible pocket for those born from 1989 to 1993 (78.3% seropositive). The age-standardised seronegative proportion decreased to 18.3% (95% CI 16.8% to 19.8%) among males and 15.6% (95% CI 10.0% to 21.2%) among females in 2013, and the immune fraction was not sufficiently below the herd immunity threshold. While the number of live births born to susceptible mothers in 1983 was estimated at 171 876 across Japan, in 2013 it was reduced to 23 698. Conclusions An elevated age at rubella virus infection and the presence of susceptible pockets among adults were observed in Japan. Although, overall, the absolute number of rubella cases has steadily declined in Japan, the elevated age of rubella cases, along with increased numbers of susceptible adults, contributed to the observation of as many as 45 congenital rubella syndrome (CRS) cases, which calls for supplementary vaccination among susceptible adults. Assessing herd immunity is considered essential for routinely monitoring the risk of future rubella epidemics and CRS cases. PMID:26817640

  2. Health risk assessment of personal inhalation exposure to volatile organic compounds in Tianjin, China.

    PubMed

    Zhou, Jian; You, Yan; Bai, Zhipeng; Hu, Yandi; Zhang, Jiefeng; Zhang, Nan

    2011-01-01

    Volatile Organic Compounds (VOCs) exposure can induce a range of adverse human health effects. To date, however, personal VOCs exposure and residential indoor and outdoor VOCs levels have not been well characterized in the mainland of China, less is known about health risk of personal exposure to VOCs. In this study, personal exposures for 12 participants as well as residential indoor/outdoor, workplace and in vehicle VOCs concentrations were measured simultaneously in Tianjin, China. All VOCs samples were collected using passive samplers for 5 days and were analyzed using Thermal Desorption GC-MS method. U.S. Environmental Protect Agency's Inhalation Unit Risks were used to calculate the inhalation cancer health risk. To assess uncertainty of health risk estimate, Monte Carlo simulation and sensitivity analysis were implemented. Personal exposures were greater than residential indoor exposures as expected with the exception of carbon tetrachloride. Exposure assessment showed modeled and measured concentrations are statistically linearly correlated for all VOCs (P<0.01) except chloroform, confirming that estimated personal exposure using time-weighted model can provide reasonable estimate of personal inhalation exposure to VOCs. Indoor smoking and recent renovation were identified as two major factors influencing personal exposure based on the time-activity pattern and factor analysis. According to the cancer risk analysis of personal exposure, benzene, chloroform, carbon tetrachloride and 1,3-butadiene had median upper-bound lifetime cancer risks that exceeded the U.S. EPA benchmark of 1 per one million, and benzene presented the highest median risks at about 22 per one million population. The median cumulative cancer risk of personal exposure to 5 VOCs was approximately 44 per million, followed by indoor exposure (37 per million) and in vehicle exposure (36 per million). Sensitivity analysis suggested that improving the accuracy of exposure measurement in further

  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. Exposure assessment at extremely low frequencies: Issues, instrumentation, modeling, and data

    NASA Astrophysics Data System (ADS)

    Sussman, Stanley S.

    1995-01-01

    Epidemiologic studies suggesting a possible link between exposure to ELF magnetic fields and increased cancer risk have spurred interest in the assessment of field levels and exposures in residences, the workplace, and other environments. Characteristics such as high degrees of spatial and temporal variability and the presence of multiple frequencies can complicate assessment strategies. Instrumentation development has proceeded rapidly, and a number of measurement systems of varying sophistication are now commercially available. For situations where measurement is not feasible or practical, computer modeling is expanding the scope of exposure estimation. Health-oriented studies and measurement surveys are adding to a growing database of field and exposure levels.

  6. 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

  7. 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

  8. 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. PMID:11859431

  9. Hydrogeologic assessment of exposure to solvent-contaminated drinking water: Pregnancy outcomes in relation to exposure

    SciTech Connect

    Wrensch, M.; Swan, S.; Murphy, P.J.; Lipscomb, J.; Claxton, K.; Epstein, D.; Neutra, R. )

    1990-07-01

    We recently concluded that exposure to solvent-contaminated drinking water was an unlikely explanation for observed excesses of adverse pregnancy outcomes during 1980-1981 in the Los Paseos neighborhood of Santa Clara County, California, because these excesses were not observed in an adjacent exposed area. The validity of this conclusion depends on the assumption that the two areas had comparable exposure. Using quantitative methods to model movement of the solvent leak plume and water flow within the distribution system, we estimated that women with adverse outcomes were no more likely to have received contaminated water than women with normal live births. These results strengthen the conclusion that exposures to water from the contaminated well were not responsible for the excess of adverse outcomes observed in the Los Paseos area.

  10. Estimated exposure to phthalates in cosmetics and risk assessment.

    PubMed

    Koo, Hyun Jung; Lee, Byung Mu

    2004-12-01

    Some phthalates such as di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) and their metabolites are suspected of producing teratogenic or endocrine-disrupting effects. To predict possible human exposure to phthalates in cosmetics, the levels of DEHP, diethyl phthalate (DEP), DBP, and butylbenzyl phthalate (BBP) were determined by high-performance liquid chromatography (HPLC) in 102 branded hair sprays, perfumes, deodorants, and nail polishes. DBP was detected in 19 of the 21 nail polishes and in 11 of the 42 perfumes, and DEP was detected in 24 of the 42 perfumes and 2 of the 8 deodorants. Median exposure levels to phthalates in cosmetics by dermal absorption were estimated to be 0.0006 g/kg body weight (bw)/d for DEHP, 0.6 g/kg bw/d for DEP, and 0.103 g/kg bw/d for DBP. Furthermore, if phthalates in cosmetics were assumed to be absorbed exclusively via 100% inhalation, the median daily exposure levels to phthalates in cosmetics were estimated to be 0.026 g/kg bw/d for DEHP, 81.471 g/kg bw/d for DEP, and 22.917 g/kg bw/d for DBP, which are far lower than the regulation levels set buy the Scientific Committee on Toxicity, Ecotoxicity, and the Environment (CSTEE) (37 g/kg bw/d, DEHP), Agency for Toxic Substances and Disease Registry (ATSDR) (7000 g/kg bw/d, DEP), and International Programme on Chemical Safety (IPCS) (66 g/kg bw/d, DBP), respectively. Based on these data, hazard indices (HI, daily exposure level/regulation level) were calculated to be 0.0007 for DEHP, 0.012 for DEP, and 0.347 for DBP. These data suggest that estimated exposure to-phthalates in the cosmetics mentioned are relatively small. However, total exposure levels from several sources may be greater and require further investigation.

  11. Effects analysis of time-varying or repeated exposures in aquatic ecological risk assessment of agrochemicals.

    PubMed

    Reinert, Kevin H; Giddings, Jeffrey M; Judd, Laura

    2002-09-01

    Exposure to agrochemicals in the aquatic environment often occurs as time-varying or repeated pulses. Time-varying exposures may occur due to runoff events and spray drift associated with precipitation and application events. Hydrologic dilution, dispersion, and degradation also produce pulsed exposures. Standard laboratory toxicity tests using constant exposure concentrations typically do not investigate the toxicity of time-varying or repeated exposures. Detoxification, elimination, and recovery may occur within organisms or populations during the periods between exposures. The difficulty of estimating effects of realistic time-varying exposures from measurements made under constant exposure conditions is often an important source of uncertainty in ecological risk assessment of pesticides. This article discusses the criteria and tools for deciding whether time-varying exposures are relevant in a particular risk assessment, approaches for laboratory toxicity testing with time-varying exposure, modeling approaches for addressing effects oftime-varying exposure, deterministic and probabilistic ecological risk characterization of time-varyingexposures and toxicity, and uncertainty analysis.

  12. 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

  13. 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.

  14. 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.

  15. 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. PMID:22401880

  16. 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.

  17. 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...

  18. 30 CFR 62.110 - Noise exposure assessment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... must: (i) Be made without adjustment for the use of any hearing protector; (ii) Integrate all sound... Cn is the total time the miner is exposed at a specified sound level, and Tn is the reference duration of exposure at that sound level shown in Table 62-1. (1) The mine operator must use Table...

  19. 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

  20. 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.

  1. 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...

  2. Assessing Sources of Human Methylmercury Exposure Using Stable Mercury Isotopes

    PubMed Central

    2015-01-01

    Seafood consumption is the primary route of methylmercury (MeHg) exposure for most populations. Inherent uncertainties in dietary survey data point to the need for an empirical tool to confirm exposure sources. We therefore explore the utility of Hg stable isotope ratios in human hair as a new method for discerning MeHg exposure sources. We characterized Hg isotope fractionation between humans and their diets using hair samples from Faroese whalers exposed to MeHg predominantly from pilot whales. We observed an increase of 1.75‰ in δ202Hg values between pilot whale muscle tissue and Faroese whalers’ hair but no mass-independent fractionation. We found a similar offset in δ202Hg between consumed seafood and hair samples from Gulf of Mexico recreational anglers who are exposed to lower levels of MeHg from a variety of seafood sources. An isotope mixing model was used to estimate individual MeHg exposure sources and confirmed that both Δ199Hg and δ202Hg values in human hair can help identify dietary MeHg sources. Variability in isotopic signatures among coastal fish consumers in the Gulf of Mexico likely reflects both differences in environmental sources of MeHg to coastal fish and uncertainty in dietary recall data. Additional data are needed to fully refine this approach for individuals with complex seafood consumption patterns. PMID:24967674

  3. 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…

  4. 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...

  5. DOSE-RESPONSE MODELING FOR THE ASSESSMENT OF CUMULATIVE RISK DUE TO EXPOSURE TO N-METHYL CARBAMATE PESTICIDES

    EPA Science Inventory

    The US EPAs N-Methyl Carbamate Cumulative Risk Assessment (NMCRA) assesses the effect on acetylcholine esterase (AChE) activity of exposure to 10 N-methyl carbamate (NMC) pesticides through dietary, drinking water, and residential exposures.

  6. No Evidence of an Association Between Efavirenz Exposure and Suicidality Among HIV Patients Initiating Antiretroviral Therapy in a Retrospective Cohort Study of Real World Data.

    PubMed

    Nkhoma, Ella T; Coumbis, John; Farr, Amanda M; Johnston, Stephen S; Chu, Bong Chul; Rosenblatt, Lisa C; Seekins, Daniel; Villasis-Keever, Angelina

    2016-01-01

    Recently, published studies have reported conflicting results regarding the association between efavirenz exposure and the risk of suicidality among patients with human immunodeficiency virus. The objective of this analysis was to compare the rate of suicidality among patients initiating efavirenz-containing versus efavirenz-free antiretroviral (ARV) regimens.This retrospective cohort study used US administrative claims data for commercially and Medicaid-insured individuals for the years 2006 to 2013. ARV-naive patients aged ≥12 years initiating an efavirenz-containing or efavirenz-free ARV regimen with ≥6 months of continuous insurance enrollment prior to ARV initiation were selected. The primary outcome was suicidality, defined as the occurrence of any medical claim with a diagnosis code for suicidal ideation or an inpatient or emergency department medical claim for suicide attempt. Unadjusted incidence rates were calculated and propensity score-adjusted hazard ratios were estimated to account for differences in patient characteristics.There were 19,983 patients (efavirenz-containing, n = 11,187; efavirenz-free, n = 8796) in the commercial database and 5154 patients (efavirenz-containing, n = 2224; efavirenz-free, n = 2930) in the Medicaid database. Unadjusted incidence rates (95% confidence interval [CI]) of suicidality per 1000 person-years were: commercial, efavirenz-containing (3.3 [2.4-4.4]), efavirenz-free (4.0 [2.7-5.8]); Medicaid, efavirenz-containing (25.7 [18.8-34.4]), efavirenz-free (40.6 [31.9-50.9]). In propensity score-adjusted analyses, efavirenz use was not associated with suicidality: adjusted hazard ratio (95% CI) of suicidality compared with efavirenz-free regimen, commercial, 1.029 (0.636-1.665); Medicaid, 0.902 (0.617-1.319).This analysis found no conclusive evidence of an increased risk of suicidality among patients initiating an efavirenz-containing ARV regimen. However, channeling bias may exist even after adjusting for

  7. No Evidence of an Association Between Efavirenz Exposure and Suicidality Among HIV Patients Initiating Antiretroviral Therapy in a Retrospective Cohort Study of Real World Data

    PubMed Central

    Nkhoma, Ella T.; Coumbis, John; Farr, Amanda M.; Johnston, Stephen S.; Chu, Bong Chul; Rosenblatt, Lisa C.; Seekins, Daniel; Villasis-Keever, Angelina

    2016-01-01

    Abstract Recently, published studies have reported conflicting results regarding the association between efavirenz exposure and the risk of suicidality among patients with human immunodeficiency virus. The objective of this analysis was to compare the rate of suicidality among patients initiating efavirenz-containing versus efavirenz-free antiretroviral (ARV) regimens. This retrospective cohort study used US administrative claims data for commercially and Medicaid-insured individuals for the years 2006 to 2013. ARV-naive patients aged ≥12 years initiating an efavirenz-containing or efavirenz-free ARV regimen with ≥6 months of continuous insurance enrollment prior to ARV initiation were selected. The primary outcome was suicidality, defined as the occurrence of any medical claim with a diagnosis code for suicidal ideation or an inpatient or emergency department medical claim for suicide attempt. Unadjusted incidence rates were calculated and propensity score-adjusted hazard ratios were estimated to account for differences in patient characteristics. There were 19,983 patients (efavirenz-containing, n = 11,187; efavirenz-free, n = 8796) in the commercial database and 5154 patients (efavirenz-containing, n = 2224; efavirenz-free, n = 2930) in the Medicaid database. Unadjusted incidence rates (95% confidence interval [CI]) of suicidality per 1000 person-years were: commercial, efavirenz-containing (3.3 [2.4–4.4]), efavirenz-free (4.0 [2.7–5.8]); Medicaid, efavirenz-containing (25.7 [18.8–34.4]), efavirenz-free (40.6 [31.9–50.9]). In propensity score-adjusted analyses, efavirenz use was not associated with suicidality: adjusted hazard ratio (95% CI) of suicidality compared with efavirenz-free regimen, commercial, 1.029 (0.636–1.665); Medicaid, 0.902 (0.617–1.319). This analysis found no conclusive evidence of an increased risk of suicidality among patients initiating an efavirenz-containing ARV regimen. However, channeling bias may exist

  8. Exposure assessment of oxidant gases and acidic aerosols

    SciTech Connect

    Lioy, P.J.

    1989-01-01

    Clearly the presence of high ozone and acidic species in North America is primarily dependent upon photochemical air pollution. Evidence shows, however, that high acid exposures may occur in specific types of areas of high sulfur fuel use during the winter. At the present time, our concerns about exposure to local populations and regional populations should be directed primarily toward the outdoor activity patterns of individuals in the summer, and how those activity patterns relate to the location, duration, and concentrations of ozone and acid aerosol in photochemical air pollution episodes. Lioy Dyba and Mage et al have examined the activity patterns of children in summer camps. Because they spend more time outside than the normal population, these children form an important group of exercising individuals subject to photochemical pollution exposures. The dose of ozone inhaled by the children in the two camps was within 50% and 25% of the dose inhaled by adults in controlled clinical situations that produced clinically significant decrements in pulmonary function and increased the symptoms after 6.6 hr exposure in a given day. The chamber studies have used only ozone, whereas in the environment this effect may be enhanced by the presence of a complex mixture. The work of Lioy et al in Mendham, New Jersey found that hydrogen ion seemed to play a role in the inability of the children to return immediately to their normal peak expiratory flow rate after exposure. The camp health study conducted in Dunsville, Ontario suggested that children participating in a summer camp where moderate levels of ozone (100 ppb) but high levels of acid (46 micrograms/m3) occurred during an episode had a similar response. Thus, for children or exercising adults who are outdoors for at least one hour or more during a given day, the presence and persistence of oxidants in the environment are of particular concern. 63 references.

  9. 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.

  10. 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.

  11. A task-based approach to assessing lead exposure among iron workers engaged in bridge rehabilitation.

    PubMed

    Goldberg, M; Levin, S M; Doucette, J T; Griffin, G

    1997-03-01

    The assessment of worker exposures to airborne contaminants in the dynamic environment present at most construction sites poses considerable challenges to the industrial hygienist. In this study, we applied a task-based approach to the assessment of lead exposure among structural steel iron workers engaged in a large, complex bridge rehabilitation project. We evaluated the usefulness of task-based exposure data for the development of worker protection programs. Task-specific and multitask samples were collected, and operation-specific and 8-hr time-weighted averages were calculated. The task-specific data showed significant differences in exposure levels among different tasks. Arithmetic mean exposures varied from 1,357 micrograms/m3 lead for torch cutting and 989 micrograms/m3 for scaling to 31 micrograms/m3 for reaming and 4 micrograms/m3 for drilling. Our task-specific data were compared with the task-based exposure levels presented by OSHA in its Lead Exposure in Construction-Interim Final Rule (29 CFR 1926). There was good general agreement between our results and OSHA's reported data. Task-based data were very useful in exposure assessment and much more precise than full-shift and operation-based measurements in guiding strategies for worker protection. These findings suggest that task-based data should routinely be collected in evaluating exposure to lead and perhaps other toxic substances in construction work.

  12. 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...

  13. 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.…

  14. A FRAMEWORK FOR ASSESSING HEALTH RISK OF ENVIRONMENTAL EXPOSURES TO CHILDREN (FINAL)

    EPA Science Inventory

    EPA has released a 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...

  15. 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...

  16. 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. PMID:27090106

  17. 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...

  18. 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. PMID:26684750

  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. 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.

  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. 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...

  3. 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.

  4. 43 CFR 11.37 - Must the authorized official confirm exposure before implementing the Assessment Plan?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... authorized official confirm exposure before implementing the Assessment Plan? (a) Before including any type B... data, such as those collected for response actions by the OSC, or other available studies or surveys of... analyses shall be limited to the number and type required for confirmation of exposure. (3) Where...

  5. Implementation and validation of a modeling framework to assess personal exposure to black carbon.

    PubMed

    Dons, Evi; Van Poppel, Martine; Kochan, Bruno; Wets, Geert; Int Panis, Luc

    2014-01-01

    Because people tend to move from one place to another during the day, their exposure to air pollution will be determined by the concentration at each location combined with the exposure encountered in transport. In order to estimate the exposure of individuals in a population more accurately, the activity-based modeling framework for Black Carbon exposure assessment, AB(2)C, was developed. An activity-based traffic model was applied to model the whereabouts of individual agents. Exposure to black carbon (BC) in different microenvironments is assessed with a land use regression model, combined with a fixed indoor/outdoor factor for exposure in indoor environments. To estimate exposure in transport, a separate model was used taking into account transport mode, timing of the trip and degree of urbanization. The modeling framework is validated using weeklong time-activity diaries and BC exposure as revealed from a personal monitoring campaign with 62 participants. For each participant in the monitoring campaign, a synthetic population of 100 model-agents per day was made up with all agents meeting similar preconditions as each real-life agent. When these model-agents pass through every stage of the modeling framework, it results in a distribution of potential exposures for each individual. The AB(2)C model estimates average personal exposure slightly more accurately compared to ambient concentrations as predicted for the home subzone; however the added value of a dynamic model lies in the potential for detecting short term peak exposures rather than modeling average exposures. The latter may bring new opportunities to epidemiologists: studying the effect of frequently repeated but short exposure peaks on long term exposure and health. PMID:24161448

  6. 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

  7. Refinement of the Nanoparticle Emission Assessment Technique into the Nanomaterial Exposure Assessment Technique (NEAT 2.0).

    PubMed

    Eastlake, Adrienne C; Beaucham, Catherine; Martinez, Kenneth F; Dahm, Matthew M; Sparks, Christopher; Hodson, Laura L; Geraci, Charles L

    2016-09-01

    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.

  8. 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. PMID:21964505

  9. 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.

  10. Evaluating Exposures to Chemical and Non-Chemical Stressors in a Cumulative Risk Assessment

    EPA Science Inventory

    Characteristically toxicological and epidemiological studies involving chemical mixtures (e.g., multi-pollutant exposures) have been increasing. Human health assessment of chemical and nonchemical mixture risk remains rare. Recently, there has been an increased emphasis on integr...

  11. 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...

  12. The influence of clinicians' previous trauma exposure on their assessment of child abuse risk.

    PubMed

    Regehr, Cheryl; LeBlanc, Vicki; Shlonsky, Aron; Bogo, Marion

    2010-09-01

    Research has identified high levels of trauma exposure and PTSD in professionals responsible for assessing children at risk for abuse. An important question arising is the influence of stress and trauma on professional judgment. This study examined the association between critical incident exposure, PTSD and workers' judgments of child risk. Ninety-six child protection workers participated in 2 simulated clinical interviews and subsequently completed standardized risk assessment measures. Workers reported high levels of exposure to critical events in the workplace and high levels of traumatic stress symptoms. Number of prior critical events encountered was negatively associated with assessment of risk. Level of traumatic stress symptoms was negatively associated with risk on one, but not other measures of risk. It is concluded that standardized measures for assessing a child's risk of abuse may be influenced by previous exposure to critical workplace events and levels of traumatic stress in workers. PMID:20823721

  13. 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 (...

  14. 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...

  15. Chronic disease and early exposure to air-borne mixtures. 2. Exposure assessment

    SciTech Connect

    James Argo

    2007-10-15

    This work is part of a larger study of the impact of early exposure to releases from industry on the etiology of cancer. Releases from all kraft and sulfite mills, coke ovens, oil refineries, copper, nickel, and lead/zinc smelters operating in Canada during the exposure period of 1967-1970 have been determined. All plumes have been expressed in g BaP eq/d using the RASH methodology. The releases have been divided into process, boiler fuel, dioxin, and SO{sub 2} emissions. Combustion sources have been defined with FIREv6.23. Dioxin congenors are expected in all source types when the boiler fuel is heavy fuel oil, wood or wood bark, or coal. All about 90 communities examined have an inverted sex ratio. 53 refs., 2 figs., 4 tabs.

  16. Using transportation demand models to assess regional noise exposure

    NASA Astrophysics Data System (ADS)

    Kaliski, Kenneth

    2005-09-01

    In the United States, most metropolitan areas run some type of transportation demand model to estimate regional travel patterns, and, to some extent, air pollution. The more advanced of these models accurately represent the geographic contours of the roadways (in contrast to the older straight-line node and link models). This allows an almost seamless integration of these new transportation demand models into noise prediction models. Combined with the locations of individual homes from a separate E911 database, we can readily make estimates of the noise exposure of populations over large areas. In this paper, the regional traffic noise exposure of residences of Chittenden County, VT is estimated and mapped. It was found that 30% of the residences are exposed to noise levels exceeding the WHO sleep disturbance level of 45 dB LAeq(8) and 20% of residences are exposed to levels exceeding the WHO ``serious annoyance'' level of 55 dB LAeq(16). Maps show noise contours as well as individual homes color coded based on relative day and night noise exposure levels. Measured sound level data are given for particular locations to validate the predictions.

  17. Assessment of noise exposure for indoor and outdoor firing ranges.

    PubMed

    Murphy, William J; Tubbs, Randy L

    2007-09-01

    The National Institute for Occupational Safety and Health (NIOSH) received an employee request for a health hazard evaluation of a Special Weapons Assault Team (SWAT) in January 2002. The department was concerned about noise exposures and potential hearing damage from weapons training on their indoor and outdoor firing ranges. NIOSH investigators conducted noise sampling with an acoustic mannequin head and 1/4 -inch microphone to characterize the noise exposures that officers might experience during small arms qualification and training when wearing a variety of hearing protection devices provided by the department. The peak sound pressure levels for the various weapons ranged from 156 to 170 decibels (dB SPL), which are greater than the recommended allowable 140 dB SPL exposure guideline from NIOSH. The earplugs, ear muffs, and customized SWAT team hearing protectors provided between 25 and 35 dB of peak reduction. Double hearing protection (plugs plus muffs) added 15-20 dB of peak reduction. PMID:17654224

  18. 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

  19. 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. PMID:26853828

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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. PMID:26583907

  5. 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.

  6. [The methods of assessment of health risk from exposure to radon and radon daughters].

    PubMed

    Demin, V F; Zhukovskiy, M V; Kiselev, S M

    2014-01-01

    The critical analysis of existing models of the relationship dose-effect (RDE) for radon exposure on human health has been performed. Conclusion about the necessity and possibility of improving these models has been made. A new improved version ofthe RDE has been developed. A technique for assessing the human health risk of exposure to radon, including the method for estimating of exposure doses of radon, an improved model of RDE, proper methodology risk assessment has been described. Methodology is proposed for the use in the territory of Russia.

  7. 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.

  8. A model to assess personal exposure to ELF magnetic fields from common household sources

    SciTech Connect

    Delpizzo, V. )

    1990-01-01

    Emission data are inadequate to characterize the contribution of a source to the total personal extremely-low-frequency (ELF) magnetic field exposure. In this paper, a simple model is proposed that takes into consideration the position of the subject with respect to the source and the duration of exposure. The magnetic field is spatially averaged over the whole body of the exposed subject and integrated over time. Exposure is regarded as significant if it approaches or exceeds 400 microT-h/year. By use of this method, the ELF magnetic fields generated by several household sources were compared with the levels of residential external sources, to assess their relative significance. Some common domestic electrical appliances are found to be responsible for an exposure comparable to that from power lines. When the model is used to assess exposure to electric blankets, apparently conflicting findings may be reconciled.

  9. Assessing exposure to air toxics relative to asthma.

    PubMed Central

    Weisel, Clifford P

    2002-01-01

    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

  10. 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

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

    PubMed

    Lesmes-Fabian, Camilo; Binder, Claudia R

    2013-04-01

    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

  12. 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.

  13. 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

  14. Bisphenol A exposure pathways in early childhood: Reviewing the need for improved risk assessment models.

    PubMed

    Healy, Bridget F; English, Karin R; Jagals, Paul; Sly, Peter D

    2015-01-01

    Bisphenol A (BPA) is a plasticiser found in a number of household plastics, electronics, and food-packaging materials. Over the past 5 years, several human epidemiological studies have reported a positive association between BPA exposure and adverse health outcomes in children, including obesity, asthma, preterm birth, and neuro-behavioural disturbances. These findings are in conflict with international environmental risk assessment models, which predict daily exposure levels to BPA should not pose a risk to child health. The aim of this review is to provide an overview of the evidence for different exposure sources and potential exposure pathways of BPA in early childhood. By collating the findings from experimental models and exposure associations observed in human bio-monitoring studies, we affirm the potential for non-dietary sources to make a substantial contribution to total daily exposure in young children. Infants and toddlers have distinctive exposure sources, physiology, and metabolism of endocrine-disrupting chemicals. We recommend risk-assessment models implement new frameworks, which specifically address exposure and hazard in early childhood. This is particularly important for BPA, which is present in numerous products in the home and day-care environments, and for which animal studies report contradictory findings on its safety at environmentally relevant levels of exposure. PMID:26350983

  15. 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

  16. 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

  17. 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

  18. 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...

  19. 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%.

  20. Environmental exposure assessment in European birth cohorts: results from the ENRIECO project.

    PubMed

    Gehring, Ulrike; Casas, Maribel; Brunekreef, Bert; Bergström, Anna; Bonde, Jens Peter; Botton, Jérémie; Chévrier, Cecile; Cordier, Sylvaine; Heinrich, Joachim; Hohmann, Cynthia; Keil, Thomas; Sunyer, Jordi; Tischer, Christina G; Toft, Gunnar; Wickman, Magnus; Vrijheid, Martine; Nieuwenhuijsen, Mark

    2013-01-23

    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

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Exposure-driven risk assessment: applying exposure-based waiving of toxicity tests under REACH.

    PubMed

    Rowbotham, Anna L; Gibson, Rosemary M

    2011-08-01

    The REACH Regulation 1907/2006/EC aims to improve knowledge of the potential risks to humans and the environment of the large number of chemicals produced and used in the EU. The testing requirements are likely to trigger numerous toxicological studies, potentially involving millions of experimental animals, despite the professed goal of REACH to reduce vertebrate testing. It may be necessary therefore to shift emphasis away from animal studies towards more pragmatic strategies, reserving animal tests for the substances of greatest concern. One approach is to waive certain tests based on levels of exposure to the substance. This review explores application of 'Exposure-Based Waiving' (EBW) of toxicity studies, with a particular focus on inhalation where possible, considering the potential qualitative and quantitative supporting arguments that might be made, including the use of thresholds of toxicological concern. Incorporating EBW into intelligent testing strategies for substance registration could advance the goals of REACH and the 3Rs (reduction, replacement and refinement of animals in research) by reducing the usage of animals in toxicity tests, whilst maintaining appropriate protection of human health and the environment. However greater regulatory evaluation, acceptance and guidance are required for EBW to achieve its full impact.

  7. Combining a Job-Exposure Matrix with Exposure Measurements to Assess Occupational Exposure to Benzene in a Population Cohort in Shanghai, China

    PubMed Central

    Friesen, Melissa C.; Coble, Joseph B.; Lu, Wei; Shu, Xiao-Ou; Ji, Bu-Tian; Xue, Shouzheng; Portengen, Lutzen; Chow, Wong-Ho; Gao, Yu-Tang; Yang, Gong; Rothman, Nathaniel; Vermeulen, Roel

    2012-01-01

    Background: Generic job-exposure matrices (JEMs) are often used in population-based epidemiologic studies to assess occupational risk factors when only the job and industry information of each subject is available. JEM ratings are often based on professional judgment, are usually ordinal or semi-quantitative, and often do not account for changes in exposure over time. We present an empirical Bayesian framework that combines ordinal subjective JEM ratings with benzene measurements. Our aim was to better discriminate between job, industry, and time differences in exposure levels compared to using a JEM alone. Methods: We combined 63 221 short-term area air measurements of benzene exposure (1954–2000) collected during routine health and safety inspections in Shanghai, China, with independently developed JEM intensity ratings for each job and industry using a mixed-effects model. The fixed-effects terms included the JEM intensity ratings for job and industry (both ordinal, 0–3) and a time trend that we incorporated as a b-spline. The random-effects terms included job (n = 33) and industry nested within job (n = 399). We predicted the benzene concentration in two ways: (i) a calibrated JEM estimate was calculated using the fixed-effects model parameters for calendar year and JEM intensity ratings; (ii) a job-/industry-specific estimate was calculated using the fixed-effects model parameters and the best linear unbiased predictors from the random effects for job and industry using an empirical Bayes estimation procedure. Finally, we applied the predicted benzene exposures to a prospective population-based cohort of women in Shanghai, China (n = 74 942). Results: Exposure levels were 13 times higher in 1965 than in 2000 and declined at a rate that varied from 4 to 15% per year from 1965 to 1985, followed by a small peak in the mid-1990s. The job-/industry-specific estimates had greater differences between exposure levels than the calibrated JEM estimates (97.5th

  8. Assessment of children's long-term exposure to magnetic fields (The Geomet study)

    SciTech Connect

    Koontz, M.D. ); Koontz, M.D.; Mehegan, L.L.; Dietrich, F.M.; Nagda, N.L. )

    1992-11-01

    Past epidemiologic studies have had conflicting results concerning a possible association between childhood cancer and magnetic field exposure, perhaps because indirect measures of exposure were used. This pilot study was conducted to assess day-today and seasonal variations in children's exposure, the contributions of different environments to total exposure, and the level of measurement/observational detail needed to accurately predict or classify children's exposures. Twenty-eight children in two age groups (8 to 11 years and under 4 years) were personally monitored for exposure to magnetic fields. All subjects were monitored for two consecutive days during winter or spring, and 12 of the subjects were monitored during both seasons. Surrogates for exposure were developed from observation of wiring configurations, indoor/outdoor spot measurements of field strength, and continuous stationary monitoring at selected indoor locations in parallel with personal monitoring. The results indicate that a single monitoring episode may be insufficient for characterization of long-term exposure, and spot measurements at one point in time may not be adequate to predict exposure. For this study, wire codes and measures based on parallel stationary monitoring in the child's bedroom were the best surrogates for personal exposure.

  9. Exposure assessment of dietary cadmium: findings from shanghainese over 40 years, China

    PubMed Central

    2013-01-01

    Background Environmental exposure to cadmium causes renal dysfunction and bone damage. Cadmium contamination in food is regarded as the main environmental source of non-occupational exposure. The aim of this study was to assess the contribution of dietary cadmium exposure in environmental cadmium exposure and its health risk among adults in Shanghai, China. Methods A cross-sectional survey about food consumption was conducted in 2008 among 207 citizens aged over 40 years in Shanghai, China. The food frequency questionnaire was combined with food, tobacco and water cadmium exposure to estimate the daily environmental cadmium exposure in both point and probabilistic estimations. Urine and blood samples of the participants were analyzed for internal exposure to total cadmium. Correlation analysis was conducted between the internal cadmium exposure and environmental cadmium exposure. Results According to the point estimation, average daily environmental cadmium exposure of the participants was 16.7 μg/day and approached 33.8% of the provisional tolerable daily intake (PTDI). Dietary and tobacco cadmium exposure approached 25.8% and 7.9% of the PTDI, respectively. Males had higher levels of dietary cadmium exposure than females (p?=?0.002). The probabilistic model showed that 93.4% of the population did not have any health risks from dietary cadmium exposure. By sensitivity analysis, tobacco consumption, tobacco cadmium level, cadmium in vegetables and cadmium in rice accounted for 27.5%, 24.9%, 20.2% and 14.6% of the total cadmium exposure, respectively. The mean values of urinary and blood cadmium among the study population were 0.5 μg/L and 1.9 μg/L, respectively. Positive correlations were observed between environmental cadmium exposure and blood cadmium (R?=?0.52, P<0.01), tobacco cadmium intake and blood cadmium excluding non-smokers (R?=?0.26, P?=?0.049<0.05), and urine cadmium and age (R?=?0.15, P?=?0.037). Conclusions It has been suggested that there is no

  10. 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...

  11. 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...