Exposure Assessment Task Group
Scholarly Products 1995 - 2000
| A coupled
forest fire emission and atmospheric dispersion model: An
application to the Savannah River Site (SRS) Author: Gurer, K., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Reports Publication Date: 2000 Citation: Computational Chemodynamics Laboratory technical report, October. Abstract: The forest and wild vegetation at or near U.S. Department of Energy (DOE) nuclear and hazardous waste sites can become depositories of hazardous wastes released in liquid, gaseous and solid form. Forest fires and wild fires at such sites can emit into the atmosphere gaseous and particulate forms of contaminants that have over time accumulated in the biomass, and thus can create health risks for workers and nearby populations. This work studies the transport and surface deposition patterns of contaminants emitted into the atmosphere from hypothetical forest fires with the objective of developing tools for the investigation of potential health risks to human populations living at and near DOE sites. A meteorological/dispersion numerical model employing the Regional Atmospheric Modeling System (RAMS) was coupled with a forest fire propagation/emission model: (1) to estimate the amount of gaseous and particulate phase contaminants that can be released from forest fires occurring at or near DOE hazardous and nuclear waste sites, and (2) to simulate the transport and deposition of these forest fire contaminants in order to predict their spatial and temporal impact. The coupled model was applied to a prescribed fire field study conducted on December 5, 1975 at the Savannah River Site (SRS). This numerical experiment was performed (1) to re-create atmospheric conditions for the above study, (2) to estimate release of contaminants from the fire, and (3) to study the transport (advection and dispersion) of these contaminants by the prevailing wind. A Large Eddy Simulation (LES) approach was used to realistically simulate fire propagation and to investigate its effects (a) on the 3-D spatial structure of gaseous and particulate phase components released from it and (b) on the 3-D spatial structure of the local meteorology. The forest fire boundary as a function of time was determined using values reported from the 1975 field study. Gaseous and particulate phase contaminant emissions were estimated using relations reported by the U.S. Forest Ser vice. The 3-D spatial patterns for the air concentrations of species such as C02, NMHC, Total Particulate Matter (TPM), and of a hypothetical radionuclide emitted from the fire into the atmosphere, and the 2-D spatial distributions of dry deposition of contaminants at the ground were calculated. Model results were qualitatively compared to (and found to generally agree with) observed concentration patterns reported during the prescribed fire field study. An alternative, idealized, fire propagation scheme, that calculates the forest fire boundary using an evolving elliptical shape, was also incorporated in the model for use in hypothetical wild fires scenarios. It is expected that the results from the present work will be utilized in defining the required attributes of less comprehensive models needed to assess potential human exposure and risk associated with forest and wild fires occurring near DOE sites. |
| A distributed
parameter physiologically-based pharmacokinetic model for
dermal and inhalation exposure to volatile organic
compounds Author: Roy, A., Other Author(s): C.P. Weisel, P.J. Lioy, and P.G. Georgopoulos. Document Type: CRESP Published Manuscripts Publication Date: 1996 Citation: Risk Analysis 16(2): 147-160. Abstract: Estimates of den-nal dose from exposures to toxic chemicals are typically derived using models that assume instantaneous establishment of steady-state dermal mass flux. However, dermal absorption theory indicates that this assumption is invalid for short-term exposures to volatile organic chemicals (VOCs). A generalized distributed parameter physiologically-based pharmacokinetic model (DP-PBPK), which describes unsteady state dermal mass flux via a partial differential equation (Fickian diffusion), has been developed for inhalation and dermal absorption of VOCS. In the present study, the DP-PBPK model has been parameterized for chloroform, and compared with two simpler PBPK models of chloroform. The latter arc lumped parameter models, employing ordinary differential equations, that do not account for the dermal absorption time lag associated with the accumulation of permanent chemical in tissue represented by permeability coefficients. All dure models were evaluated by comparing simulated post-exposure exhaled breath concentration profiles with measured concentrations following environmental chloroform exposures. The DP-PBPK model predicted a time-lag in the exhaled breath concentration profile, consistent with the experimental data. The DP-PBPK model also predicted significant volatilization of chloroform, for a simulated dermal exposure scenario. The end-exposure dermal dose predicted by the DP-PBPK model is similar to that predicted by the EPA recommended method for short-term exposures, and is significantly greater than the end-exposure dose predicted by the lumped parameter models. However, the net dermal dose predicted by the DP-PBPK model is substantially less than that predicted by the EPA method, due to the post-exposure volatilization predicted by the DP-PBPK model. Moreover, the net dermal dose of chloroform predicted by all three models was nearly the same, even though the lumped parameter models did not predict substantial volatilization. |
| A new
mechanistic model for the resuspension of particulate
matter. Poster Author: Kevrekidis, P.G., Other Author(s): M. Lazaridis and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| A
physiologically based pharmacokinetic model for
2,3,7,8-tetrachlorodibenzo-p-dioxin in bivalve mollusks Author: Moreno, M.D., Other Author(s): K.R. Cooper, R.P. Brown, and P.G. Georgopoulos. Document Type: CRESP In Press Manuscripts Publication Date: 200X Citation: Environmental Toxicology and Chemistry. Abstract: |
| A unified
kinetic approach to binary nucleation Author: Kevrekidis, P., Other Author(s): M. Lazaridis, Y. Drossinos, and P.G. Georgopoulos. Document Type: CRESP Published Manuscripts Publication Date: 1999 Citation: Journal of Chemical Physics 111: 8010-8012. Abstract: |
| Addressing
uncertainty and variability in physiologically based
pharmacokinetic models. Symposium on aggregate exposure
assessments: Defininf and evaluating uncertainty and
variability. Poster Author: Roy, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Annual Society for Risk Analysis Conference. Abstract: |
| Adult proxy
responses to a survey of children's dermal soil contact
activities Author: Wong, E.Y., Other Author(s): J.H. Shirai, T.J. Garlock, and J.C. Kissel. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Journal of Exposure Analysis and Environmental Epidemiology. Abstract: |
| Ambient
gaseous leak detection using radial scanning computed
tomography and optical remote sensing. Author: Hashmonay, R.A., Other Author(s): M.G. Yost, and C.-F. Wu. Document Type: CRESP Proceedings Publication Date: 1998 Citation: SPIE Environmental Monitoring and Remediation Technologies Conference, 126-132. Boston, November. Abstract: |
| Ammonia
emissions at Hanford's tank farms using computed
tomography and remote optical sensing of
emissions(CT-ROSE) system. Poster Author: Hashmonay, R.A. Other Author(s): and M.G. Yost. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: Annual Hanford Site Conference Abstract: |
| An integrated
exposure and dose modeling and analysis system - Part II:
Integration of environmental and microenvironmental
components using GIS tools Author: Walia, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP In Progress Manuscripts Publication Date: 200X Citation: Abstract: |
| An integrated
microenvironmental exposure and dose modeling and
analysis system with geographic information system
components Author: Walia, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: 90th A&WMA Meeting. Toronto, June 10-13. Abstract: |
| Analytical
cytology: Applications to neurotoxicology Author: Catlin, M.C., Other Author(s): M. Guizzetti, R.A. Ponce, and T.J. Kavanagh. Document Type: CRESP In Press Manuscripts Publication Date: 200X Citation: Current Methods in Toxicology. Abstract: |
| Applying
OP-FTIR with a radial beam geometry to locate a leak in
indoor environments: improvements in temporal resolution.
Poster Author: Wu, C.F., Other Author(s): R.A. Hashmonay, R.S. Crampton, and M.G. Yost. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Annual American Industrial Hygien Conference & Exposition Abstract: |
| Assessment of
dermal ecposure to soils. Poster Author: Kissel, J., Other Author(s): T. Garlock, and J. Shirai. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Assessment of
dermal exposure to soils Author: Kissel, J.C., Other Author(s): T. Garlock, and J. Shirai. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: Sixth International FZK/TNO Conference on Contaminated Soil. Edinburgh, Scotland, May. Abstract: |
| Atmospheric
dispersion and resuspension of particulate matter:
Evaluation of modeling techniques and new developments. Author: Georgopoulos, P.G., Other Author(s): M. Lazaridis, and P.G. Kevrekidis. Document Type: CRESP Reports Publication Date: 1999 Citation: Computational Chemodynamics Laboratory technical report. Abstract: |
| Atmospheric
dispersion of particulate matter: An evaluation of
modeling techniques for applicability to DOE sites Author: Lazaridis, M., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Researcher Reports Publication Date: 1996 Citation: Abstract: |
| Background
soil quality and relationships between surface and
subsurface soil samples from the Savannah River Site.
Poster Author: Vyas, V.M., Other Author(s): D.H. Berler, A. Skiadas, P.G. Georgopoulos, and D.S. Kosson. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Bayesian data
assimilation techniques for risk assesment models:The
markov chain Monte Carlo simulation methodology. Poster Author: Roy, A. Other Author(s): S.S. Isukapalli, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: AIChE 1998 Annual Meeting, Miami, Fl Abstract: |
| Bayesian data
assimilation techniques for risk assessment models:The
markov chain monte carlo simulation methodology. Author: Roy, A., Other Author(s): S. Isukapalli, and P.G. Georgopoulos. Document Type: CRESP Proceedings Publication Date: 1998 Citation: Pollution Prevention and Environmental risk Reduction Topical Conference Proceedings, 264-271. Miami, November 15-20. Abstract: |
| Bioavailability
measurements of chromium, lead and arsenic using in vitro
and in vivo approaches of a NIST certified standard
reference material Author: Ellickson, K.M., Other Author(s): R.J. Meeker, M.A. Gallo, B.T. Buckley, and P.J. Lioy. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Toxicological Sciences. Abstract: |
| Bioavailability
studies to improve risk assessment at SRS. Poster Author: McGrath, L.F., Other Author(s): K. Cooper, K. Ellickson, B. Hart, and P. Lioy. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Responsive science: Forging regulatory resolution at DOE sites, Washington, DC, April 12. Abstract: |
| Biomarkers of
environmental benzene exposure Author: Weisel, C., Other Author(s): R. Yu, A. Roy, and P.G. Georgopoulos. Document Type: CRESP Published Manuscripts Publication Date: 1996 Citation: Environmental Health Perspectives 104(Supplement 6): 1141-1146. Abstract: Environmental exposures to benzene result in increases in body burden that are reflected in various biomarkers of exposure, including benzene in exhaled breath, benzene in blood and urinary trans-tran-muconic acid and S-phenylmercapturic acid. A review of the literature indicates that these biomarkers can be used to distinguish populations with different levels of exposure (such as smokers from nonsmokers and occupationally exposed from environmentally exposed populations) and to determine differences in metabolism. Biomarkers in humans have shown that the percentage of benzene metabolized by the ring-opening pathway is greater at environmental exposures than that at higher occupational exposures, a trend similar to that found in animal studies. This suggests that the dose-response curve is nonlinear; that potential different metabolic mechanisms exist at high and low doses; and that the validity of a linear extrapolation of adverse effects measured at high doses to a population exposed to lower, environmental levels of benzene is uncertain. Time-series measurements of the biomarker, exhaled breath, were used to evaluate a physiologically based pharmacokinetic (PBPK) model. Biases were identified between the PBPK model predictions and experimental data that were adequately described using an empihcal compartmental model. It is suggested that a mapping of the PBPK model to a compartmental model can be done to optimize the parameters in the PBPK model to provide a future framework for developing a population physiologically based pharmacokinetic model. |
| Breath
sampling as a biomarker of exposure Author: Chien, Y-C., Other Author(s): C. Weisel, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Annual Meeting of the Society for Risk Analysis and the International Society of Exposure Analysis. New Orleans, LA. Abstract: |
| Case studies
demonstrating the integration of macro-and
micro-environmental modeling using GIS for exposure
assessments Author: Walia, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: 7th Annual Meeting of the ISEA. Research Triangle Park, NC, November. Abstract: |
| Characterization
of dermal contact with soil Author: Kissel, J.C. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: EPA Dermal Workshop. Washington, DC, August. Abstract: |
| Characterization
of soil adherence to skin: Impact of historical
misinterpretation of the Que Hee et al. Data Author: Kissel, J.C. Other Author(s): Document Type: CRESP Published Manuscripts Publication Date: 1995 Citation: Risk Analysis 15 (6): 613-614. Abstract: Replacement of point estimates of exposure parameters with probabilistic descriptions that incorporate knowledge of the uncertainty and variability of those parameters is a worthy goal. The attractiveness of that goal should not, however, overshadow traditional requirements for plausibility and reproducibility of parameter derivations. Recently Finley et aL(l) proposed a probability density function (PDF) for soil adherence to skin based on data obtained from the prior literature. Individual distributions constructed from each of six data sources were sampled to produce an overall PDF. The mean, median and 95th percentile of a distribution ostensibly bootstrapped from the data of Que Hee et al. (2) are presented in Table 1. A previous interpretation of the Que Hee et aL data by Sedman(3) produced the point estimate shown in the fourth colunm of Table 1. Sedman's estimate, which is the basis for the lower limit of the default range in EPA's most recent dermal guidance (4) is much larger than the 95th percentile of the distribution generated by Finley et aL Finley et al. cite Sedman's work, but offer no explanation of the apparent discrepancy between their PDF and prior interpretation of the same data. Examination of the original source of the data in question reveals that both interpretations are incorrect. |
| Comparison
between a kinetics based model and fugacity based
bioaccumulation model for movements fo pcb's in the great
lakes. Author: Hunter, J.G., Other Author(s): A. Roy, K. Cooper, and P.G. Georgopoulos. Document Type: CRESP Reports Publication Date: 1999 Citation: Abstract: |
| Comparison of
predicted exposures to soil contaminants with results of
biomonitoring at selected sites Author: Kissel, J.C, Other Author(s): and W. Wawrukiewicz. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: AMSIE '97 and American Association for the Advancement of Science (AAAS) Annual Meeting. Session on "Pathways of Exposure to Contaminants in Surface Soils: Do We Know Enough to Know How Clean is Clean. Seattle, WA, February 13-18. Abstract: |
| Comparison of
soil ingestion rates derived from dose reconstruction at
contaminated sites with estimates obtained in tracer mass
balance studies Author: Kissel, J., Other Author(s): S. Bartell, and W. Wawrukiewicz. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1996 Citation: Society for Risk Analysis (SRA) and International Society for Exposure Assessment (ISEA) Joint Meeting. New Orleans, LA, December 8-11. Abstract: |
| Comparison of
the efficiency and robustness of methods for uncertainty
analysis. Poster Author: Roy, A., Other Author(s): S. Isukaplli, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Annual Society for Risk Analysis Conference. Abstract: |
| Comparison of
the terrestrial bioacumulation model(cats) and pathway
for Cs137 movement in ecosystems of the Nevada test Site
and environs. Author: Hunter, J.G., Other Author(s): A. Roy, K. Cooper, and P.G. Georgopoulos. Document Type: CRESP Reports Publication Date: 1999 Citation: Abstract: |
| Computational
methods for the efficient sensitivity and uncertainty
analysis of models for environmental and biological
systems-towards a framework for an exposure and dose
modeling and analysis sytem. Author: Isukapalli, S., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Reports Publication Date: 1999 Citation: Computational chemodynamics laboratory tech. CCL/EDMAS-03 (181pp) Abstract: |
| Computationally
efficient methods of uncertainty analysis for
environmental models Author: Isukapalli, S., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Proceedings Publication Date: 1996 Citation: In proceedings from the A&WMA Specialty Conference on Computing in Environmental Resource Management. Research Triangle Park, NC, December 2-4. Abstract: |
| Computed
tomography of air pollutants using radial scanning
path-integrated optical remote sensing Author: Hashmonay, R.A., Other Author(s): M.G. Yost, and C.F. Wu. Document Type: CRESP Published Manuscripts Publication Date: 1999 Citation: Atmospheric Environment 33: 267-274. Abstract: We propose a novel application of computed tomography (CT) for path-integrated optical remote sensing of air pollutants. We conducted a preliminary study with data obtained from simulated scanning of non-overlapping radial beam segments through Gaussian test distributions and experimentally measured test maps. The smooth basis function minimization (SBFM) algorithm, which fits parametric distributions rather than fitting individual pixel concentrations, was used to reconstruct two-dimensional concentration maps from this beam geometry. The results show that quite good reconstructions are possible with this approach. In contrast to the complex beam geometries proposed in the past for CT, this technique could be applied directly to air monitoring data from a variety of current optical sensing instruments. This development could vastly broaden the application of CT to obtain rapid reconstructions of ambient air pollution data. |
| Data and
model assimilation using a bayesian methodology: Markov
chain monte carlo (mcmc) simulation. Poster Author: Roy, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Defining
background groundwater quality for the Savannah River
Site. Poster Author: Vyas, V.M., Other Author(s): A. Roy, E. Massry, D.S. Kosson, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Dermal soil
loadings associated with selected activities Author: Holmes, K., Other Author(s): J. Kissel, J. Shirai, and K. Richter. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Environmental Research. Abstract: |
| Design and
preliminary testing of a system that integrates
relational database, gis and web browser technologies to
manage ambient environmental data Author: Arunachalam , S., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Proceedings Publication Date: 1996 Citation: A & WMA Specialty Conference on Computing in Enviromental Resource Management. Research Triangle Park, NC, Dec 2-4. Abstract: |
| Detection of
ammonia distributions in outdoor environments using open
path ftir and computed tomoraphy. Poster Author: Wu, C.F., Other Author(s): R.A. Hashmonay, R.S. Crampton, and M.G. Yost. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Annual Human Exposures to Environmental Contaminants Research Symposium Abstract: |
| Development
and evaluation of a multiscale environmental exposure and
dose modeling system Author: Georgopoulos, P.G. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Integrating Risk, Restoration and Future Use of the Savannah River Site, sponsored by DOE, SRS, CRESP, SREL and WSRC. Savannah River Ecology Laboratory, September. Abstract: |
| Development
and evaluation of an exposure and dose analysis system
(EDMAS). Poster Author: Walia, A. Other Author(s): A. Roy, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1996 Citation: Society of Environmental Journalists Mid-Atlantic Regional Conference and EOHSI Tenth Anniversary Celebration. Abstract: |
| Development
and evaluation of an overlapped multiple emitted ray
(OMER) geometry for application of OP-FTIR with computed
tomography Author: Yost, M.G., Other Author(s): X.X. Park, and X.X. Levine. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Air and Waste Management Association Journal Abstract: |
| Development
and testing of a modeling system for assessing the
environmental impact of forest fires Author: Gurer, K., Other Author(s): M. Lazaridis, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: Tenth Joint Conference on the Applications of Air Pollution Meteorology, 78th AMS Annual Meeting. Phoenix, AZ, January 11-16. Abstract: |
| Development
of a radial scanning beam configuration for
identification of gas leak location with use of an
OP-FTIR and computed tomographic technique . Poster Author: Wu, C., Other Author(s): Ram A. Hashmonay, Doo-Yong Park, and Michael G. Yost. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Dosimetry
modeling of inhaled particles in the respiratory tract Author: Lazaridis, M., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: 7th Annual Meeting of the ISEA. Research Triangle Park, NC, November. Abstract: |
| Dry
deposition of large, airborne particles onto a surrogate
surface Author: Kim, E., Other Author(s): D. Kalman, and T. Larson. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Atmospheric Environment. Abstract: |
| Effects of
vapor extraction on contaminant flux to atmosphere and
ground water Author: Poulsen, T.G., Other Author(s): J.W. Massmann, and P. Moldrup. Document Type: CRESP Published Manuscripts Publication Date: 1996 Citation: Journal of Environmental Engineering 122(8): 700-706. Abstract: Numerical simulations were used to evaluate the effects of vapor extraction operations on contaminant loadings to the atmosphere, the ground water, and to the vapor extraction well under application of vapor extraction. A two-dimensional numerical model for simulating migration of a volatile contaminant partitioned between the nonaqueous phase liquid, air, water, and solid phases in the unsaturated zone was developed and used in this study. The model was based on an explicit finite difference scheme. The sensitivity of vapor extraction efficiency and contaminant migration to system parameters was investigated. Results from model simulations show that well vacuum, nonaqueous phase liquid-air mass transfer rate, and inhomogencities in soil air conductivity have a significant influence on contaminant flux and the time required for contaminant removal. Contaminant loadings to the atmosphere and ground water were strongly dependent on well vacuum and soil air conductivity, but were almost independent on nonaqueous phase liquid-air mass transfer rate. |
| Efficient
senstivity/uncertainty analysis combining stochastic
response surface and automatic differentiation methods Author: Isukapalli, S., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Environmental and Biological Systems. Abstract: |
| Emission rate
apportionment from fugitive sources using open-path FTIR
and mathematical inversion Author: Hashmonay R.A., Other Author(s): M.G. Yost, Y. Mamane, and Y. Benayahu. Document Type: CRESP Published Manuscripts Publication Date: 1999 Citation: Atmospheric Environment 33: 735-743. Abstract: This paper presents a detailed new methodology to address emissions from non-homogeneous fugitive gaseous air pollution sources. An open-path FTIR system is employed in a new field configuration, in which the main measurement path located downwind from the source and segmented into several secondary paths. The segmentation can be performed by retroreflectors or black bodies situated along the main measurement path, for a unistatic system or bistatic system respectively. An inversion technique is used, in conjunction with plume dispersion modeling techniques to reconstruct the emission rates distribution from different strips of the fugitive source. A field study to evaluate and validate the proposed methodology was conducted. In the validation field study, large and relatively cold black bodies ( ~ 1OO°C) were successfully used as the sources of infrared radiation. Emission rates from three controlled emission point sources of SF, were reconstructed by applying the suggested methodology, and agreed quite well in most runs of the field study. |
| Empirical
investigation of hand-to-mouth transfer Author: Kissel, J., Other Author(s): J. Shirai, K. Richter, and R. Fenske. Document Type: CRESP Published Manuscripts Publication Date: 1998 Citation: Bulletin of Environmental Contamination and Toxicology 60: 379-386. Abstract: Estimates of risk attributable to soil contamination are often dependent upon assumed soil ingestion rates. Sources of ingestion rate estimates include calculation from assumptions regarding soil loading on hands, frequency of hand-to-mouth contact, and efficiency of transfer. For instance, Lepow et al. (1975) speculated that children might pass 10 mg of soil from hand to mouth 10 times per day, leading to ingestion of 100 mg of soil per day. Duggan and Williams (1977) produced a smaller estimate by assuming the relevant skin area involved only a part of one finger or a thumb, but also assumed 10 events per day. Alternative estimates derived from analyses of childrens' diets and excreta for elemental tracers (Calabrese and Stanek 1989, 1995; Davis et al. 1991) have since become available. However, those studies (which are subject to contradictory interpretation) do not explain the manner in which soil is ingested. Quantitative characterization of the process by which soil is transferred from children's hands to their mouths does not yet exist. In the case of adult soil ingestion rates, even less information is available. Hawley's (1985) estimate of ingestion of up to 480 mg of soil by adults on "active" days is cited in the Exposure Factors Handbook (EPA 1990) and sometimes appears in risk assessments. It is based on the assumption that an individual might transfer half the soil in a 3.75 mg/cm^2 layer covering the palmar side of the fingers and thumb of both hands from hand to mouth twice in a single day. Sheppard (1995) revisited Hawley's calculations and produced lower estimates primarily on the basis of lower assumed soil loadings. Prior soil ingestion estimates for both children and adults based on hypothetical exposure scenarios are summarized in Table 1. Results of a laboratory-based examination of hand-to-mouth transfer of soil are reported here. This work was undertaken to provide an empirical basis for evaluating assumptions used to estimate masses of soil and contaminant that might be transferred from hand to mouth. |
| Estimating
maximum concentrations for open path monitoring along a
fixed beam path Author: Yost, M.G., Other Author(s): R. A. Hashmonay, Y. Zhou, R. Spear, D.Y. Park, and S. Levine. Document Type: CRESP Published Manuscripts Publication Date: 1999 Citation: Journal of the Air Waste Management Association 49: 174-185. Abstract: Researchers have applied open path optical sensing techniques to a variety of workplace and environmental monitoring problems. Usually these data are reported in terms of a path-average (or path-integrated) concetration. When assessing potential human exposures along a beam path, this path-average value is not always informative, since concentrations along the path can vary substantially from the beam average. The focus of this research is to arrive at a method for estimating the upper-bound in contaminant concetrations over a fixed open beam path. The approach taken here uses a statistical model to estimate an upper-bound concentration based on a combination of the path-average and a measure of the spatial variability computed from point samples along the beam path. Results of computer simulations and experimental testing in a controoled ventilation chamber indicate that the model produced conservative estimates for the maximum concentration along the beam path. This approach may have many applicatons for open path monitoring in workplaces or wherever maximum concentrations are a concern. |
| Estimation of
bioavailability using deconvolution Author: Roy, A., Other Author(s): P.G. Georgopoulos , R.J. Meeker, E.C. Faria, M.A. Gallo, and P.J. Lioy. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: 7th Annual Meeting of the ISEA, Research Triangle Park, NC, November. Abstract: |
| Estimation of
bioavailability using deconvolution. Poster Author: Roy, A., Other Author(s): P.G. Georgopoulos, and P.J. Lioy. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Estimation of
childhood soil ingestion rates using a probabilistic
toxicokinetic lead model. Poster Author: Bartell, S.M., Other Author(s): J.H. Shirai, C.H. Pierce, and J.C. Kissel. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Society for Risk Analysis Annual Meeting. Atlanta, GA, December. Abstract: |
| Estimation of
the bioavailable fraction of metal contaminants in soils
using synthetic bio-fluids extractions Author: Buckley, B., Other Author(s): S. Hamel, W. Fang, C. Gilmartin, and P. Lioy. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1996 Citation: Society for Risk Analysis (SRA) and International Society for Exposure Assessment (ISEA) Joint Meeting. New Orleans, LA., December 8-11. Abstract: |
| Evaluating a
radial beam geometry for mapping indoor air contaminants:
OP-FTIR application to locate a leak in indoor
environments. Author: Wu, C.F. Other Author(s): Document Type: CRESP Dissertations or Theses Completed Publication Date: 1998 Citation: Master's Thesis, University of Washington Abstract: |
| Evaluation of
a physiologically based pharmacokinetic model for
perchloroethylene in humans at environmental exposure
levels. Poster Author: Roy, A., Other Author(s): Y-C. Chien, C. Weisel, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: ISEE/ISEA Joint Conference Abstract: |
| Evaluation of
a revised protocol for assessment of dermal exposure to
soil contaminants Author: Kissel, J.C., Other Author(s): and T. Garlock. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Annual Meeting of the Society for Risk Analysis. Washington, DC. December. Abstract: |
| Evaluation of
binary chemical mixtures on early life stages of
freshwater fish. Poster Author: Cooper, K., Other Author(s): A. Skiadas, A. Roy, P.G. Georgopoulos, L. McGrath, and J. Burger. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Evaluation of
physiologically based population pharmacokinetic models
developed using Markov Chain Monte Carlo simulation
methodology Author: Roy, A., Other Author(s): S. Isukapalli, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: SEE/ISEA Joint Conference. Boston, MA, August. Abstract: |
| Evaluation of
the predictive capability of models of exposure to soil
contaminants Author: Kissel, J., Other Author(s): A. Wawrukiewicz, S. Bartell, and J. Shiral. Document Type: CRESP Proceedings Publication Date: 1998 Citation: Contaminated Soil '98: Proceedings of the Sixth International FZK/TNO Conference on Contaminated Soil, edited by Thomas Telford, 2 of 2, 1049-1050. Edinburgh, United Kingdom, May 17-21. Abstract: Clean-up decisions regarding contaminated soils are typically based on rudimentary exposure assessments. In the U.S., these assessments have historically employed simple deterministic models of potential pathways. Concern over the cost of clean-ups has fostered criticism of regulatory models as excessively cautious. In particular, inclusion of high-end estimates of multiple exposure factors can be expected to lead to compounded conservation. The primary remedy for this problem involves use of distributed parameters and characterization of uncertainty and variability in expected exposures. While stochastic description of exposure factors is intellectually much more appealing than traditional deterministir methods, implementation is hindered by the same lack of information that led to the use of conservative point estimates in the past. Validation of probabilistic models is therefore appropriate, but in practice has seldom been attempted. This is in part due to a lack of data against which model predictions can be tested. Deliberate exposure of human subjects in a manner adequate to test the models in question is problematical. However, some data are available as a result of post hoc biomonitoring conducted at sites where exposure due to soil contamination were suspected. |
| Evaluation of
the predictive capability of models of exposure to soil
contaminants. Poster Author: Kissel, J.C., Other Author(s): A. Wawrukiewicz, and S.M. Bartell. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: Sixth International FZK/TNO Conference on Contaminated Soil, Edinburgh, Scotland, May. Abstract: |
| Evaluation of
the predictive capability of models of exposure to soil
contaminants. Poster Author: Kissel, J., Other Author(s): A. Wawrukiewicz, S. Bartell, and J. Shirai. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Exposure
assessment Author: Kalman, D. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1996 Citation: Short course Hazardous Waste Solvents in Subsurface Environments: Transport, Risks, Remediation. CRESP, Seattle, WA, September 9-11. Abstract: |
| Exposure
measurement needs for hazardous waste sites: Two case
studies Author: Georgopoulos, P.G., Other Author(s): and P.J. Lioy. Document Type: CRESP Published Manuscripts Publication Date: 1996 Citation: Toxicology and Industrial Health 12(5): 651-665. Abstract: The science of exposure assessment has been expanding both its theoretical and experimental bases over the past two years. Recent theoretical work published by the authors in the Journal of Exposure Analysis and Environmental Epidemiology (Volume 4, Number 3, 1994) has defined a multistep process to couple measurement data with mathematical models of exposure and dose. The present manuscript discusses the need for improving the measurement of exposure in order to reduce uncertainties in the potential risk and, eventually, the occurrences of health outcomes in the community environment. The discussion focuses on hazardous waste sites and how improving or routinely introducing exposure measurements to the remedial investigation can lead to a better understanding of how the potential population can get exposed via single or multiple activities. This information can help to better understand the need for specific remediation actions and selection of the types of models that can be used to predict exposure for a large population and to estimate the reduction in postremediation exposure for a local population (National Research Council, 1991). |
| Exposure to
soil contaminants via dermal contact Author: Bunge, R., Other Author(s): and J. Kissel. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: AMSIE '97 and American Association for the Advancement of Science (AAAS) Annual Meeting. Seattle, WA., February 13-18. Abstract: |
| Field
measurement of dermal soil loading attributable to
various activities: Implications for exposure assessment Author: Kissel, J.C., Other Author(s): K.Y. Richter, and R.A. Fenske. Document Type: CRESP Published Manuscripts Publication Date: 1996 Citation: Risk Analysis 16(1): 115-125. Abstract: Estimates of soil adherence to skin are required for assessment of dermal exposures to contaminants in soils. Previously available estimates depend heavily on indirect measurements and/or artificial activities and reflect sampling of hands only. Results are presented here from direct measurement of soil loading on skin surfaces of volunteers before and after normal occupational and recreational activities that might reasonably be expected to lead to soil contact. Skin surfaces assayed included hands, forearms, lower legs, faces and/or feet. Observed hand loadings vary over five orders of magnitude (roughly from 10^-3 to 10^2 mg/cm^2) and are dependent upon type of activity. Hand loadings within the current default range of 0.2 to 1.0 mg/cm^2 were produced by activities providing opportunity for relatively vigorous soil contact (rugby, fanning). Loadings less than 0.2 mg/cm^2 were found on hands following activities presenting less opportunity for direct soil contact (soccer, professional grounds maintenance) and on other body parts under manyconditions. The default range does not, however, represent a worst case. Children playing in mud on the shore of a lake generated geometric mean loadings well in excess of 1 mg/cm^2 on hands, arms, legs, and feet. Post-activity average loadings on hands were typically higher than average loadings on other body parts resulting from the same activity. Hand data from limited activities cannot, however. be used to conservatively predict loadings that might occur on other body surfaces without regard to activity since non-hand loadings attributable to higher contact activities exceeded hand loadings resulting from lower contact activities. Differences between pre- and post-activity loadings also demonstrate that dermal contact with soil is episodic. Typical background (pre-activity) geometric mean loadings appear to be on the order of 10^-2 mg/cm^2 or less. Because exposures are activity dependent, quantification of dermal exposure to soil will remain inadequate until data describing relevant human behavior (type of activity, frequency, duration including interval before bathing, clothing wom, etc.) are generated. |
| Gaseous
emission estimation from fugitive sources using optical
remote sensing and computed tomography techniques. Author: Hashmonay R.A., Other Author(s): and M.G. Yost. Document Type: CRESP Proceedings Publication Date: 1998 Citation: Pacific Basin Conference on Hazardous Waste, 414-425. Honolulu,HI, April. Abstract: |
| Gaseous
emission estimation from Hanford site fugitive sources
using optical remote sensing and computed tomography
techniques. Poster Author: Hashmony A. Ram., Other Author(s): Michael G. Yost. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Gridlib: A
gis-based tool for linking macroenvironmental to
microenvironmental models. Poster Author: Walia, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Hazardous
waste solvents in subsurface environments: Transport,
risks, and remediation Author: Kalman, D., Other Author(s): H.D. Stensel, J.W. Massmann, J.F. Ferguson, and M. Benjamin. Document Type: CRESP Educational Courses Given Publication Date: 1996 Citation: University of Washington, Department of Environmental Health. Seattle, WA, September 9-10. Abstract: |
| Human
exposure to inhalation of particulate matter resuspended
from radioactive contaminated soil Author: Lazaridis, M., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: 7th Annual Meeting of the ISEA. Research Triangle Park, NC, November. Abstract: |
| Incorporation
of behavioral data in assessment of dermal exposure to
soils Author: Kissel, J., Other Author(s): T. Garlock, and K. Holmes. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Northwest/International Section, Air and Waste Management Association Regional Meeting. Seattle, WA, December. Abstract: |
| Incorporation
of behavioral data in assessment of dermal exposure to
soils Author: Kissel, J., Other Author(s): T. Garlock, and K. Holmes. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1996 Citation: Society for Risk Analysis (SRA) and International Society for Exposure Assessment (ISEA) Joint Meeting. New Orleans, LA, December 8-11. Abstract: |
| Incorporation
of behavioral data in assessment of dermal exposure to
soils Author: Kissel, J., Other Author(s): T. Garlock, and K. Holmes. Document Type: CRESP Proceedings Publication Date: 1996 Citation: Proceedings of SRA/ISEA Joint Meeting, New Orleans, LA, December 8-11 Abstract: |
| Inhalation
dosimetry of fine airborne particulate matter:Evaluation
of modeling approaches for respiratory tract aerosol
deposition and new developments. Author: Georgopoulos, P.G., Other Author(s): D.M. Broday, P.G. Kevrekidis, and M. Lazaridis. Document Type: CRESP Reports Publication Date: 1999 Citation: Computational Chemodynamics Laboratory technical report. Abstract: |
| Innovative
approach for estimating gaseous fugitive fluxes using
computed tomography and remote optical sensing techniques
Author: Hashmonay, R.A., Other Author(s): and M.G. Yost. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Journal of the Air and Waste Management Association. Abstract: |
| Integrated
exposure and dose modeling and analysis system. I.
Formulation and testing of microenvironmental and
pharmacokinetic components Author: Georgopoulos, P.G., Other Author(s): A. Walia, A. Roy, and P.J. Lioy. Document Type: CRESP Published Manuscripts Publication Date: 1997 Citation: Environmental Science and Technology 31(1): 17-27. Abstract: The conceptual and theoretical framework for a modular integrated Exposure and Dose Modeling and Analysis System (EDMAS) has been formulated, and its stepwise implementation and testing is currently in progress. This system aims to provide state-of-the-art tools for performing integrated assessments of exposure and dose for individuals and populations. The integration of modeling components with each other as well as with available environmental, exposure, and toxicological databases is being accomplished with the use of computational tools that include interactive simulation environments, Geographical Information Systems, and various data retrieval, management, statistical analysis, and visualization methods. This paper overviews the structure and modular nature of this integrated modeling system and focuses specifically on two of its components: (a) a hierarchy of physiologically based pharmacokinetic models (PBPKM), representing various levels of detail and sophistication, and (b) a family of microenvironmental models, that incorporate complex physical and chemical transformations. The deterministic implementation of these components is also presented here in two test applications: (i) a case study of benzene exposure indoors resulting from the volatilization of contaminated tap water and (ii) a case study of photochemical pollution infiltration indoors, in an office building environment. |
| Integration
of exposure and dose modeling with geographic information
systems.nearc '97. Poster Author: Walia, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Annual Northeast ARC Users Group Conference. Abstract: |
| Integration
of geographical information systems and relational
datavases tools for environmental data access,
visualization and analysis: Application to Savannah River
Site. Poster Author: Arunachalam, S., Other Author(s): A. Skiadas, K. Karamichael, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Investigation
of dermal contact with soil in controlled trials Author: Kissel, J.C., Other Author(s): J. Shirai, K.Y. Richter, and R. A. Fenske. Document Type: CRESP Published Manuscripts Publication Date: 1998 Citation: Journal of Soil Contamination 7(6): 737-752. Abstract: |
| Investigation
of the influence of oil on soil adherence to the skin Author: Holmes, K., Other Author(s): J. Kissel, and K. Richter. Document Type: CRESP Published Manuscripts Publication Date: 1996 Citation: Journal of Soil Contamination 5(4): 301-308. Abstract: |
| Investigations
of potential human population exposures to contamination
released from forest fires in the vicinity of hazardous
chemical and nuclear waste sites Author: Gurer, K., Other Author(s): M. Lazaridis, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: 7th Annual Meeting of the ISEA. Research Triangle Park, NC, November. Abstract: |
| Investigations
of the effects of forest fires on the atmosphere using a
coupled forest-fire/meteorology-dispersion model Author: Gurer, K., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: Symposium on Thermal and Fluids Engineering. Toronto, Canada, May 19-22. Abstract: |
| Localizing
gaseous fugitive emission sources by combining real time
optical remote sensing and wind data Author: Hashmonay, R.A., Other Author(s): and M.G. Yost. Document Type: CRESP In Press Manuscripts Publication Date: 200X Citation: A & WMA Abstract: |
| Lung
dosimetry modeling for assessing exposure to fine
particulate matter. Poster Author: Broday, D., Other Author(s): P. Kevrekidis, M. Lazaridis, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: ISEE/ISEA Joint Conference Abstract: |
| Mapping air
pollutants at Hanford's tank farms using optical remote
sensing. Poster Author: Hashmonay, R.A., Other Author(s): M.G. Yost, and R.S. Crampton. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Responsive science: Forging regulatory resolution at DOE sites, Washington, DC, April 12. Abstract: |
| Mapping the
emission rates over fugitive sources using open-path FTIR
and inversion techniques Author: Hashmonay, R.A., Other Author(s): M.G. Yost, and Y. Mamane. Document Type: CRESP Proceedings Publication Date: 1996 Citation: In proceedings of the Air & Waste Management Association International Conference on Optical Sensing for Environmental and Process Monitoring. Abstract: |
| Mathematical
feasibility and data needs for reconstructing exposures
to volatile organic compounds using physiologically based
phamacokinetic models: Application to week-long benzene
exposure Author: Roy, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Published Manuscripts Publication Date: 1998 Citation: Journal of Exposure Analysis and Environmental Epidemiology 8(3): 407-422. Abstract: Reconstruction of human exposure to toxic chemicals using physiologically based pharmacokinetic (PBPK) models and biomarkers is an attractive prospect, because biomarker measurements generally provide the most direct evidence of dose. Previously it has been shown that it is possible to reconstruct short-term (30 minute) exposure to chloroform, and that it is possible in some cases to resolve the total dose between two routes of uptake (Georgopoulos et al., 1994). In this paper it is shown that it is mathematically feasible to reconstruct longer term exposures to volatile organic compounds (VOCs), using benzene as a paradigm for other VOCS, and exhaled breath concentration as a biomarker of exposure. First, it is shown that exhaled breath concentration is an appropriate biomarker for long-term exposure to benzene, since benzene accumulates in fat and is eliminated in exhaled breath. Application of a benzene PBPK model (Travis et al., 1990) showed that benzene continues to accumulate in the fat compartment for over 10 days, and consequently fat acts as an integrator of dose during this period. Second, the benzene PBPK model is used to reconstruct exposure using the maximum likelihood approach. Since no data were available for long-term exposures of this duration, "data" with a normally distributed random error and 30% coefficient of variation were generated by the PBPK model for a variety of daily exposures. It was shown that in most cases it is possible to estimate cumulative exposure within 40% of the actual values, even when the exposure concentration-time profile is unknown. The estimated exposure is found to always be an underestimate of the true exposure when the exposure concentration is assumed to be constant. |
| Mechanistic
modeling of transport and metabolism in physiological
systems - Towards a framework for an exposure and dose
modeling and analysis system. Computational Chemodynamics
Laboratory Tech. Report CCL/EDMAS-02 Author: Roy, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Researcher Reports Publication Date: 1997 Citation: Abstract: |
| Mesoscales
atmospheric transport and dispersion modeling:
Comparisons of alternative methods. Poster Author: Gurer, K., Other Author(s): and P.G. Georgopoulos Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: Protection of ecological health depends on understanding biological responses to diverse human activities. The Hanford Nuclear Reservation in eastern Washington is an ideal location to study biological responses because it has been subjected to diverse human influences in the last century and also has minimally disturbed areas of shrub-steppe. We collected invertebrates in pitfall traps at 9 study sites in 1997, 1 0 new sites in 1998, and 6 new- sites in 1999. Five sites were sampled in two years. Fifty-seven attributes (characteristics) of terrestrial invertebrate assemblages based on taxa richness, composition, and functional roles were evaluated for systematic change from undisturbed to disturbed sites. Attributes that were significantly associated with disturbance in 1997 and 1998 were selected as metrics and used to develop a multimetric index. We used 1999 data to test the index. Of the 57 attributes tested, 18 distinguished between undisturbed and disturbed sites in 1997 (p <0.06) and 22 distinguished them in 1998 (p < 0.05). In 1999, 35 attributes were significantly associated with disturbance (Spearman's r, p < 0. 05). Of all 57 attributes, 10 were consistent across all 3 years and an additional 12 attributes showed clear differences in two out of three years. Taxa richness measures that distinguished site groups included total number of invertebrate families, polyphagous Carabidae species, Diptera families, Acarina species, predator species, detritivore species, and ground-dwelling species (those with their entire life cycle in or on the ground). Relative abundance of Collembola, polyphagous Carabidae, and detritivores increased with disturbance. The final index combined 8 metrics that were not redundant. Undisturbed sites had the highest index values, sites with physical disturbance related to construction or waste disposal were next, and agricultural sites had the lowest values, indicating the highest degradation. We conclude that the index and its component metrics provide effective means to guide or evaluate development, conservation, or restoration efforts. |
| Microenvironmental
modeling integrated with Geographic Information Systems
for exposure assessment - Towards a framework for an
exposure and dose modeling and analysis system.
Computational Chemodynamics Laboratory Tech. Report
CCL/EDMAS-01 Author: Walia, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Researcher Reports Publication Date: 1997 Citation: Abstract: |
| Modeling
aerosol processes at the local scale Author: Lazaridis, M., Other Author(s): S. Isukapalli and P.G. Georgopoulos. Document Type: CRESP Proceedings Publication Date: 1998 Citation: In proceedings of 91st A&WMA Meeting. San Diego, CA, June 14-18. Abstract: |
| Modeling
particle resuspension due to bending waves Author: Kevrekidis, P., Other Author(s): M. Lazaaridis, and P.G. Georgopoulos. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: J. of Aerosol Sci. Abstract: |
| Modeling the
impact of forest fires on the emission and atmospheric
transport of contaminants. Poster Author: Gurer, K., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Multi-Beam
segmentation strategy: a new beam geometry for open-path
fourier transform infrated (OP-FTIR) exposure assessment
in workplace. Poster Author: Hashmonay, R.A., Other Author(s): and M.G. Yost. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: American Industrial Hygiene Conference Abstract: |
| Multimedia/multipathway
modeling of human exposure and dose across multiple
spatial and temporal Scales Author: Georgopoulos, P.G. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: 7th Annual Meeting of the ISEA, Research Triangle Park, NC., November. Abstract: |
| Novel
application of open-path FTIR spectroscopy to measure
aerosol ambient concentration and size distribution.
Poster Author: Hashmonay, R.A., Other Author(s): M.G. Yost, and R.S. Crampton. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Novel radial
beam geometry to detect gas leak location using OP-FTIR
and computed tomography techniques. Poster Author: Hashmonay, R.A., Other Author(s): M.G. Yost, C.F. Wu, and D.Y. Park. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Numerical
modeling of forest fires within a 3-D
meteorological/dispersion model Author: Gurer, K., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: Second Symposium on Fire and Forest Meteorology. November, January 11-16. Abstract: |
| Occupational
health and safety in the Information Age: Computer
models, databases and data management tools Author: Georgopoulos, P.G. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Universities Occupational Safety and Health Educational Resource Center (UOSHERC) 17th Annual Scientific Meeting. NYU Medical Center, April. Abstract: |
| Off-site
(non-occupational) risks Author: Kissel, J. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1996 Citation: Symposium on Risk. CRESP, Seattle, WA, May 15. Abstract: |
| On the
application of open-path fourier transform infra-red
spectroscopy to measure aerosols: Observations of water
droplets Author: Hashmonay, R.A., Other Author(s): and M.G. Yost. Document Type: CRESP Published Manuscripts Publication Date: 1999 Citation: Environmental Science and Technology 33(7): 1141-1144. Abstract: This paper proposes the application of Open-Path Fourier Transform lnfra-Red (OP-FTIR) spectroscopy to measure aerosols. A preliminary experiment conducted in a standard shower chamber generated a condensed water aerosol cloud. The OP-FTIR beam acquired spectra through the cloud of water droplets. We matched calculated extinction spectra to measured extinction in ti)e spectral range between 500 and 5000 wavenumbers by using Mie theory for spherical particles. The results indicate that size distribute on parameters may be retrieved from OP-FRIR spectra acquired over a 1 km optical path with reasonable detection limits on the order of 10 µg·m-3 for aerosols with optical properties equivalent to water. |
| Open-Path
FTIR first monitoring campaign at Hanford tank
farms-Preliminary report Author: Hashmonay, R.A., Other Author(s): R.S.Crampton and M.G.Yost. Document Type: CRESP Researcher Reports Publication Date: 1998 Citation: December 3. Abstract: |
| Open-path
ftir observation of aerosols ambient concentration and
size distributions. Poster Author: Hashmony Ram., Other Author(s): Michaeal G. Yost, and Robert S. Crampton Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Open-path
FTIR observation of water aerosol ambient concentration
and size distribution. Poster Author: Hashmonay, R.A., Other Author(s): M.G. Yost, and R.S. Crampton. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: Annual AmericanAerosol Society Conference. Abstract: |
| Oral
Bioavailability of metals from soil. Poster Author: Roy, A., Other Author(s): K.M. Ellickson, S.C. Hamel, R.J. Meeker, E.C. Faria, B. Buckley, M. A. Gallo, P.G. Georgopoulos, and P.J. Lioy. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Particle
transport project field comparison of modified rotorod
samplers and deposition samplers: Development of an
improved particle inertial deposition model. Poster Author: Kim E., Other Author(s): Timothy Larson, and David Kalman Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Particle
transport project size resolution of large airborne
particles using deposition samplers: Wind chamber tests.
Poster Author: Kim E., Other Author(s): Timothy Larson, and David Kalman. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Particulate
matter dispersion modeling at the local scale: Comparison
of the fugitive dust model with a lagrangian fluid
particle model. Poster Author: Lazaridis, M., Other Author(s): T. Larson, and P.G. Georgopoulos Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Pathways of
exposure to contaminants in surface soils: Do we know
enough to know how clean is clean Author: Bunge, R., Other Author(s): S. Davis, S. Haness, D. Layton, and T. McKone. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: AMSIE '97 and American Association for the Advancement of Science (AAAS) Annual Meeting. Seattle, WA., February 13-18. Abstract: |
| Pathways of
exposure to contaminants in surface soils: Do we know
enough to know how clean is clean Author: Kissel, J.C., Other Author(s): A. Bunge, S. Davis, S. Haness, D. Layton, and T. McKone. Document Type: CRESP Symposia, Workshops, and Stakeholder Events Publication Date: 1997 Citation: AMSIE '97 and American Association for the Advancement of Science (AAAS) Annual Meeting. Seattle, WA, February 13-18. Abstract: |
| Physical and
chemical characterization of representative Savannah
Rriver Site surface soils Author: Berler, D., Other Author(s): V.M. Vyas, P.G. Georgopoulos, and D. Kosson. Document Type: CRESP Reports Publication Date: 1999 Citation: Technical report prepared for the US Department of Energy. Abstract: |
| Physiologically
based models of dermal transport Author: Georgopoulos, P.G. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Advances in the Biology of the Skin: Pharmacology and Toxicology. NYU Medical Center, June. Abstract: |
| Probabilistic
analysis of contaminant transport at SRS: Case study
using the EPACMTP model Author: Isukapalli, S., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Researcher Reports Publication Date: 1997 Citation: April. Abstract: |
| Progress in
the continuing development and evaluation of a multiscale
environment exposure and dose modeling system Author: Georgopoulos, P.G. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: 7th Annual Meeting of the ISEA. Research Triangle Park, NC, November. Abstract: |
| Progress in
the continuing development and evaluation of a multiscale
exposure and dose modeling and analysis system Author: Georgopoulos, P.G. Other Author(s): Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Workshop on Integrating Risk, Restoration and Future Use of the Savannah River Site, Savannah River Ecology Laboratory at SRS, September 10-11. Abstract: |
| Real time gas
measurements in workplaces using open path ftir. Poster Author: Wu, C.F., Other Author(s): R.A. Hashmonay, R.S Crampton, and M.G. Yost. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Annual University of Washinton / University of British Columbia Semiahmoo Occupational and Environmental Health Conferemce Abstract: |
| Reconstrucring
week-long ecposures to volatile organic compounds using
physiologically based pharmacokinetic models Author: Roy, A., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Published Manuscripts Publication Date: 1998 Citation: J. of Exp. Anal. and Environ. Epi. 8: 407-422. Abstract: |
| Reduction of
uncertainty in the parameters of a physiological based
pharmacokinetic model for tetrachloroethylene. Author: Roy, A., Other Author(s): C-Y. Chien, C.P. Weislel, and P.G. Georgopoulos. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Risk Analysis Abstract: |
| Research to
support decisions involving exposure to contaminats from
DOE sites: Overview of the CRESP/EOHSI exposure
assessment task group activities. Poster Author: Georgopoulos, P.G., Other Author(s): L.F. McGrath, A. Roy, S. S. Isukapalli, and P.J. Lioy. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Respiratory
tract dosimetry modeling for inhaled particulate matter:
Comparison of the edmas-aid and icrp66 models. Poster Author: Lazaridis, M., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: CRESP 1998 Annual Meeting, Dingmans Ferry, Pa, June. Abstract: |
| Risk
assessment of a Department of Energy facility using site
specific bioaccessibilty data Author: McGrath L.F., Other Author(s): K. Ellickson, and E.B. Hart. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: International Society of Exposure Analysis, September 7. Abstract: |
| Savannah
River Site: Particulate emissions Author: Lazaridis, M., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Researcher Reports Publication Date: 1996 Citation: Abstract: |
| Simulation
study for gaseous fluxes from an area source using
computed tomography and optical remote sensing. Author: Hashmonay, R.A., Other Author(s): M.G. Yost, D.B. Harris, and E.L. Thompson Jr. Document Type: CRESP Proceedings Publication Date: 1998 Citation: SPIE Environmental Monitoring and Remediation Technologies Conference (November 1998, Boston, MA), PP.405-410. Abstract: |
| Source code
(FORTRAN) for inversion calculation of source location
and strength from downwind data Author: Yost, M. Other Author(s): Document Type: CRESP Computer Programs Developed Publication Date: 1997 Citation: Abstract: |
| Source-to-dose
modeling for complex exposure assessment problems: An
integrated framework and application. Poster Author: Roy, A., Other Author(s): Y-C. Chien, C.Weisel, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: ISEE/ISEA Joint Conference Abstract: |
| Stationary
and time-dependent indoor tracer-gas concentration
profiles measured by OP-FTIR remote sensing and
sbfm-computed tomography. Author: Drescher, A.C. Other Author(s): M.G. Yost, A.J. Gadgil, S.P. Levine, and W.W. Nazaroff. Document Type: CRESP Published Manuscripts Publication Date: 1997 Citation: Atmospheric Envionment 31(5),727-740 Abstract: |
| Stochastic
response surface methods (SRSM) for uncertainty
characterization and propagation: Application to
environmental and biological modeling Author: Isukapalli, S., Other Author(s): A. Roy, and P.G. Georgopoulus. Document Type: CRESP In Press Manuscripts Publication Date: 200X Citation: Risk Analysis. Abstract: |
| Stochastic
response surface methods (SRSMs) for propagation of
uncertainties in numerical process models Author: Isukapalli, S, Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1997 Citation: Annual Meeting of the American Institute of Chemical Engineers (AIChE. ) Chicago, IL, November. Abstract: |
| Studies of
multi-route exposure/dose reconstruction using
physiologically based pharmacokinetic models Author: Roy, A., Other Author(s): C.P. Weisel, M.A. Gallo, and P.G. Georgopoulos. Document Type: CRESP Published Manuscripts Publication Date: 1996 Citation: Toxicology and Industrial Health 12(2): 153-163. Abstract: Exposure assessment traditionally employs measurements or estimates of contaminant concentrations in environmental media in contact with humans. However, significant uncertainties are inherent in this approach. Media concentrations of contaminants are known to exhibit considerable spatial and temporal variability, which makes obtaining accurate estimates of exposure levels difficult. Furthermore, uncertainty is also introduced by variations in individual activity patterns and rate of uptake of contaminants. An alternative approach for assessing the impact of environmental contaminants on humans is through exposure/dose reconstruction, wherein internal dose and exposure concentrations are estimated using post-exposure measurements of suitable response metrics, such as concentration of biomarkers. Wallace et al. (1993) implemented this approach using a linear phenomenologic compartmental model. In the present study, this approach has been implemented on a mechanistic basis by using physiologically based pharmacokinetic (PBPK) models, which can incorporate nonlinear cause-effect relationships. A schematic showing the flow of information for two complementary approaches to exposure assessment (forward and backward calculation) is given in Figure 1. In the present study, PBPK models of chloroform with different representations of dermal absorption have been used to examine the accuracy of multi-media/multi-route exposure concentration reconstruction. Post-exposure, exhaled breath concentration was used as a biomarker of chloroform exposure. Because internal dose is estimated directly from biomarker data using a PBPK model, much of the uncertainty of varying exposure concentrations, human activity patterns, and uptake efficacy are avoided. As shown in Figure 1, one aim of the exposure assessment is to use the estimate of internal dose as an input to a pharmacodynamic model to determine physiological response. |
| Technical
memorandum, dosimetry of inhaled particles in the
respiratory tract: Development and testing of an aerosol
model for applicability to DOE sites Author: Lazaridis, M., Other Author(s): and P.G. Georgopoulos. Document Type: CRESP Researcher Reports Publication Date: 1997 Citation: June. Abstract: |
| Technical
memorandum: Resuspension of small, non-deformable
particles Author: Lazaridis, M., Other Author(s): Y. Drossinos, and P.G. Georgopoulos. Document Type: CRESP Researcher Reports Publication Date: 1997 Citation: April. Abstract: |
| Telephone
survey of activities relavant to contact with soils Author: Kissel, J.C., Other Author(s): and T. Garlock. Document Type: CRESP Questionaires and Instruments Utilized Publication Date: 1996 Citation: Abstract: |
| The
bioavailability of heavy metals and radionuclides from
contaminated soils using in vitro and in vivo approaches.
Author: Ellickson, K.M., Other Author(s): M.A. Gallo, R.J. Meeker, B.T. Buckley, and P.J. Lioy Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: Annual Society of Environmental Toxicology and Chemistry Abstract: |
| The
bioavailability of heavy metals and radionuclides from
contaminated soils using in vitro and invivo approaches.
Poster Author: Ellickson, K.M., Other Author(s): M.A. Gallo, R.J. Meeker, B.T. Buckly, and P.J. Lioy Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1999 Citation: ISEE/ISEA Joint Conference Abstract: |
| The
development of a PBPK model using the distribution of
2,3,7,8-tcdd in the tissues of the eastern oyster
(crassostrea virginica). Author: Wintermyer, M., Other Author(s): A. Skiadas, A. Roy, J. Burger, P.G. Georgopoulos, and K. Copper. Document Type: CRESP Submitted Manuscripts Publication Date: 200X Citation: Environ. Toxicol. and Chem. Abstract: |
| The use of
RAMS for Savannah River Site (SRS): Advanced atmospheric
modeling for emergency response Author: Gürer, K., Other Author(s): and P.G Georgopoulos. Document Type: CRESP Researcher Reports Publication Date: 1996 Citation: Abstract: |
| Trends and
future applications of optical remote sensing and
computed tomography to map air contaminants. Author: Todd, L.A., Other Author(s): M.G. Yost, and R.A. Hashmonay Document Type: CRESP Proceedings Publication Date: 1998 Citation: SPIE Environmental Monitoring and Remediation Technologies Conference (November 1998, Boston, MA), PP.399-404. Abstract: |
| Turbulent
resuspension of small non-deformable particles Author: Lazaridis, M., Other Author(s): Y. Drossinos, and P.G. Georgopoulos. Document Type: CRESP In Press Manuscripts Publication Date: 200X Citation: Journal of Colloid and Interface Science. Abstract: |
| Uncertainty
analysis of PBPK models by combining stochastic response
surface and automatic differentiation methods Author: Isukapalli, S., Other Author(s): A. Roy, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: ISEE/ISEA Joint Conference. Boston, MA, August. Abstract: |
| Uncertainty
propagation in environmental and biological process
models for risk analysis: Stochastic response surface and
automatic differentiation methods. Author: Isukapalli, S., Other Author(s): A. Roy, and P.G. Georgopoulos. Document Type: CRESP Proceedings Publication Date: 1998 Citation: Pollution Prevention and Environmental risk Reduction Topical Conference Proceedings, 264-271. Miami, November 15-20. Abstract: |
| Uncertainty
propagation in environmental and biological process
models for risk analysis: Stochastic response surface and
automatic differntiation methods. Poster Author: Isukapalli, S.S., Other Author(s): A. Roy, and P.G. Georgopoulos. Document Type: CRESP Presentations, Posters, and Abstracts Publication Date: 1998 Citation: AIChE 1998 Annual Meeting Abstract: |