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| Report number: LBNL-51854 | Year: 2002 |
| Title: Exposure to Motor Vehicle Emissions: An Intake Fraction Approach, Master's Thesis | Published in: |
| Authors: Marshall, J. | Type: Report |
| Abstract: Motor vehicles are a significant source of population exposure to air pollution. Focusing on California's South Coast Air Basin as a case study, I combine ambient monitoring station data with hourly time-activity patterns to determine the population intake of motor vehicle emissions during 1996 -- 1999. Three microenvironments are considered wherein the exposure to motor vehicle emissions is higher than in ambient air: in and near vehicles, inside a building that is near a freeway, and inside a residence with an attached garage. Total motor vehicle emissions are taken from the EMFAC model. The 15 million people in the South Coast inhale 0.0048% of primary, nonreactive compounds emitted into the basin by motor vehicles. Intake of motor vehicle emissions is 46% higher than the average ambient concentration times the average breathing rate, because of microenvironments and because of temporal and spatial correlation among breathing rates, concentrations, and population densities. Intake fraction (iF) summarizes the emissions-to-intake relationship as the ratio of population intake to total emissions. iF is a population level exposure metric that incorporates spatial, temporal, and interindividual variability in exposures. iFs can facilitate the calculation of population exposures by distilling complex emissions-transport-receptor relationships. I demonstrate this point by predicting the population intake of various primary gaseous emissions from motor vehicles, based on the intake fraction for benzene and carbon monoxide. | |
| Report number: LBNL-51582 | Year: 2002 |
| Title: Predicting Indoor Pollutant Concentrations, and Applications to Air Quality Management | Published in: Proceedings of the Joint WHO-JRC-ECA Workshop on the Role of Human Exposure Assessment in Air Quality Management, Bonn, Germany. |
| Authors: Lorenzetti, D.M. | Type: Conference Proceedings |
| Abstract: Because most people spend more than 90% of their time indoors, predicting exposure to airborne pollutants requires models that incorporate the effect of buildings. Buildings affect the exposure of their occupants in a number of ways, both by design (for example, filters in ventilation systems remove particles) and incidentally (for example, sorption on walls can reduce peak concentrations, but prolong exposure to semivolatile organic compounds). Furthermore, building materials and occupant activities can generate pollutants. This paper surveys modeling approaches for predicting pollutant concentrations in buildings, and summarizes the application of these models. | |
| Report number: LBNL-51256 | Year: 2001 |
| Title: Reconstructing exposure scenarios using dose biomarkers: An application of Bayesian uncertainty analysis | Published in: |
| Authors: Sohn, Michael D., Thomas E. McKone, Mark L. Rigas, Jerry N. Blancato, Frederick W. Power | Type: Report |
| Report number: LBNL-2370E | Year: 2009 |
| Title: CKow – A More Transparent and Reliable Model for Chemical Transfer to Meat and Milk | Published in: Submitted to Environmental Science and Technology. |
| Authors: Rosenbaum, R.K., McKone, T.E., Jolliet, O. | Type: Journal Article |
| Abstract: The objective of this study is to increase the understanding and transparency of chemical biotransfer modeling into meat and milk and explicitly confront the uncertainties in exposure assessments of chemicals that require such estimates. In cumulative exposure assessments that include food pathways, much of the overall uncertainty is attributable to the estimation of transfer into biota and through food webs. Currently, the most commonly used meat and milk-biotransfer models date back two decades and, in spite of their widespread use in multimedia exposure models few attempts have been made to advance or improve the outdated and highly uncertain Kow regressions used in these models. Furthermore, in the range of Kow where meat and milk become the dominant human exposure pathways, these models often provide unrealistic rates and do not reflect properly the transfer dynamics. To address these issues, we developed a dynamic three-compartment cow model (called CKow), distinguishing lactating and non-lactating cows. For chemicals without available overall removal rates in the cow, a correlation is derived from measured values reported in the literature to predict this parameter from Kow. Results on carry over rates (COR) and biotransfer factors (BTF) demonstrate that a steady-state ratio between animal intake and meat concentrations is almost never reached. For meat, empirical data collected on short term experiments need to be adjusted to provide estimates of average longer term behaviors. The performance of the new model in matching measurements is improved relative to existing models—thus reducing uncertainty. The CKow model is straight forward to apply at steady state for milk and dynamically for realistic exposure durations for meat COR. | |
| Report number: LBNL-2397E | Year: 2009 |
| Title: Integration of the predictions of two models with dose measurements in a case study of children exposed to the emissions of a lead smelter | Published in: Submitted to Journal of Human and Environmental Risk Assessment. |
| Authors: Bonnard, R., McKone, T.E. | Type: Journal Article |
| Abstract: The predictions of two source-to-dose models are systematically evaluated with observed data collected in a village polluted by a currently operating secondary lead smelter. Both models were built up from several sub-models linked together and run using Monte-Carlo simulation, to calculate the distribution children’s blood lead levels attributable to the emissions from the facility. The first model system is composed of the CalTOX model linked to a recoded version of the IEUBK model. This system provides the distribution of the media-specific lead concentrations (air, soil, fruit, vegetables and blood) in the whole area investigated. The second model consists of a statistical model to estimate the lead deposition on the ground, a modified version of the model HHRAP and the same recoded version of the IEUBK model. This system provides an estimate of the concentration of exposure of specific individuals living in the study area. The predictions of the first model system were improved in terms of accuracy and precision by performing a sensitivity analysis and using field data to correct the default value provided for the leaf wet density. However, in this case study, the first model system tends to overestimate the exposure due to exposed vegetables. The second model was tested for nine children with contrasting exposure conditions. It managed to capture the blood levels for eight of them. In the last case, the exposure of the child by pathways not considered in the model may explain the failure of the model. The interest of this integrated model is to provide outputs with lower variance than the first model system, but at the moment further tests are necessary to conclude about its accuracy. | |
| Report number: LBNL-520E | Year: 2008 |
| Title: Model selection and evaluation for risk assessment of dioxin contaminated sites | Published in: Ambio, Volume 36, Pages 458-466. |
| Authors: Wiberg, K., Aberg, A., McKone, T.E., Tysklind, M., Hanberg, A., Macleod, M. | Type: Journal Article |
| Abstract: The general European population has a total intake of dioxins and dioxin-like chemicals near the limit recommended by the European Union, making additional exposure above background levels undesirable. For populations living near dioxin contaminated sites additional exposure may occur by intake of locally produced food, inhalation of particles, dermal contact with soils, or by other exposure pathways. Risk assessment tools are required to estimate risks associated with contaminated sites and to set priorities for site remediation. Here, we review several multimedia models that can be applied as tools to support risk assessment. We then and present a strategy to select, apply, evaluate and adapt a model to address a specific situation. The case study we consider is a risk assessment of generic background dioxin exposure in Sweden, and we compare the predictions with environmental observations and exposure data from Sweden. Arguments are presented for selecting the CalTOX model for this case study. We demonstrate the application, evaluation and adaptation of the model, and discuss the requirements for extending the analysis to conduct risk assessment for subpopulations living near dioxin contaminated sites. | |
| Report number: LBNL-2372E | Year: 2008 |
| Title: USEtox - The UNEP-SETAC toxicity model: recommended characterisation factors for human toxicity and freshwater ecotoxicity in Life Cycle Impact Assessment | Published in: The International Journal of Life Cycle Assessment, Volume 13, Pages 532-546. |
| Authors: Rosenbaum, R.K., Bachman, T.M., Gold, L.S., Huijbregts, M., Jolliet, O., Juraske, R., Koehler, A., Larsen, H.F., Macleod, M., Margni, M., McKone, T.E., Payet, J., Schuhmacher, M., van de Meent, D., Hauschild, M.Z. | Type: Journal Article |
| Abstract: Abstract Background, Aim and Scope. In 2005 a comprehensive comparison of LCIA toxicity characterisation models was initiated by the UNEP-SETAC Life Cycle Initiative, directly involving the model developers of CalTOX, IMPACT 2002, USES-LCA, BETR, EDIP, WATSON, and EcoSense. In this paper we describe this model-comparison process and its results—in particular the scientific consensus model developed by the model developers. The main objectives of this effort were (i) to identify specific sources of differences between the models’ results and structure, (ii) to detect the indispensable model components, and (iii) to build a scientific consensus model from them, representing recommended practice. Methods. A chemical test set of 45 organics covering a wide range of property combinations was selected for this purpose. All models used this set. In three workshops, the model comparison participants identified key fate, exposure and effect issues via comparison of the final characterisation factors and selected intermediate outputs for fate, human exposure and toxic effects for the test set applied to all models. Results. Through this process, we were able to reduce inter-model variation from an initial range of up to 13 orders of magnitude down to no more than 2 orders of magnitude for any substance. This led to the development of USEtox, a scientific consensus model that contains only the most influential model elements. These were, for example, process formulations accounting for intermittent rain, defining a closed or open system environment, or nesting an urban box in a continental box. Discussion. The precision of the new characterisation factors (CFs) is within a factor of 100-1000 for human health and 10-100 for freshwater ecotoxicity of all other models compared to 12 orders of magnitude variation between the CFs of each model respectively. The achieved reduction of inter-model variability by up to 11 orders of magnitude is a significant improvement. Conclusions. USEtox provides a parsimonious and transparent tool for human health and ecosystem CF estimates. Based on a referenced database, it has now been used to calculate CFs for several thousand substances and forms the basis of the recommendations from UNEP-SETAC’s Life Cycle Initiative regarding characterization of toxic impacts in Life Cycle Assessment. Recommendations and Perspectives. We provide both recommended and interim (not recommended and to be used with caution) characterisation factors for human health and freshwater ecotoxicity impacts. After a process of consensus building among stakeholders on a broad scale as well as several improvements regarding a wider and easier applicability of the model, USEtox will become available to practitioners for the calculation of further CFs. | |
| Report number: LBNL-513E | Year: 2008 |
| Title: Carbon Sequestration Risks and Risk Management | Published in: |
| Authors: Price, P.N., McKone, T.E., Sohn, M.D. | Type: Report |
| Abstract: This section summarizes the risk assessment approaches and risk management methods that can be applied to study geologic carbon sequestration in California, including CO2 capture, transportation and storage operations. Risk assessment and risk management concepts are introduced and applied. Known hazards from carbon sequestration are discussed individually, and risk reduction options are presented. Human exposure limits, pathways for human and environmental exposure during operations and post‐operations, and how risks change over the time scales associated with storage as the CO2 migrates and reacts in the subsurface environment, are also discussed. | |
| Report number: LBNL-1246E | Year: 2008 |
| Title: Insecticide Exposures on Commercial Aircraft: A Literature Review and Screening Level Assessment | Published in: |
| Authors: Maddalena, R.L., McKone, T.E. | Type: Report |
| Abstract: The objective of this project was to provide initial estimates of the relationship between insecticide use on passenger aircraft and exposure levels present in the cabin environment. The work was initially divided into three tasks including 1) a review of insecticide application practices in commercial aircraft, 2) exploratory measurements of insecticide concentrations in treated aircraft and 3) screening level exposure modeling. Task 1 gathered information that is needed to assess the time-concentration history of insecticides in the airline cabin. The literature review focused on application practices, information about the cabin environment and existing measurements of exposure concentrations following treatment. Information from the airlines was not available for estimating insecticide application rates in the U.S. domestic fleet or for understanding how frequently equipment rotate into domestic routes following insecticide treatment. However, the World Health Organization (WHO) recommends several methods for treating aircraft with insecticide. Although there is evidence that these WHO guidelines may not always be followed, and that practices vary by airline, destination, and/or applicator company, the guidelines in combination with information related to other indoor environments provides a plausible basis for estimating insecticide loading rates on aircraft. The review also found that while measurements of exposure concentrations following simulated aerosol applications are available, measurements following residual treatment of aircraft or applications in domestic aircraft are lacking. Task 2 focused on developing an approach to monitor exposure concentrations in aircraft using a combination of active and passive sampling methods. An existing active sampling approach was intended to provide data immediately following treatment while a passive sampler was developed to provide wider coverage of the fleet over longer sampling periods. The passive sampler, based on a thin-film polymer-coated glass design, was developed specifically for deployment in the airliner ventilation system for long-term unattended monitoring of insecticide loading in the aircraft. Because access was not available for either treated aircraft or treatment records during the course of this study, the development and calibration of the passive samplers was halted prior to completion. Continued development of a field ready passive sampler for insecticides in aircraft would require collaboration with the airline industry to finalize the method for deployment and calibration conditions for the sampler. The Task 3 screening level modeling assessment used a dynamic two-box mass balance model that includes treated surfaces and air to explore the time-concentration history of insecticides in the cabin. The model was parameterized using information gathered during the literature review and run for several different insecticide use scenarios. Chemical degradation or sequestration in the surface compartment and mass transfer from the surface to the air limit the rate at which insecticides are removed from the system. This rate limiting process can result in an accumulation of insecticide in the airliner cabin following repeated applications. The extent of accumulation is a function of the overall persistence of the chemical in the system and the amount of chemical applied during each treatment. | |
| Report number: | Year: 2008 |
| Title: Polybrominated diphenyl ethers and polychlorinated biphenyls in human breast adipose samples from Brazil | Published in: Environmental Research, In Press. |
| Authors: Kalantzi, O.I., Brown, F.R., Caleffi, M., Goth-Goldstein, R., Petreas, M. | Type: Journal Article |
| Report number: LBNL-752E | Year: 2008 |
| Title: Carbonyl Emissions from Gasoline and Diesel Motor Vehicles | Published in: Environmental Science and Technology, Volume 42, Pages 4697-4703. |
| Authors: Jakober, C.A. , Robert, M.A. , Riddle, S.G. , Destaillats, H., Charles, M.J., Green, P.G., Kleeman, M.J. | Type: Journal Article |
| Abstract: Carbonyls from gasoline powered light-duty vehicles (LDVs) and heavy-duty diesel powered vehicles (HDDVs) operated on chassis dynamometers were measured using an annular denuder-quartz filter-polyurethane foam sampler with -(2,3,4,5,6-pentafluorobenzyl)hydroxylamine derivatization and chromatography-mass spectrometry analyses. Two internal standards were utilized based on carbonyl recovery, 4-fluorobenzaldehyde for | |
| Report number: LBNL-2421E | Year: 2008 |
| Title: Regulatory Models and the Environment Practice, Pitfalls, and Prospects | Published in: Submitted to Risk Analysis. |
| Authors: Holmes, K.J., Graham, J.A., McKone, T.E., Whipple, C | Type: Journal Article |
| Abstract: regulatory models, evaluation, uncertainty analysis | |
| Report number: | Year: 2008 |
| Title: Cellular response to diesel exhaust particles strongly depends on the exposure method | Published in: Toxicological Sciences, Volume 103, Pages 108-115. |
| Authors: Holder, A.H., Lucas, D., Goth-Goldstein, R., Koshland, C.P. | Type: Journal Article |
| Report number: LBNL-507E | Year: 2008 |
| Title: Building a model based on scientific consensus for Life Cycle Impact Assessment of Chemicals: the Search for Harmony and Parsimony | Published in: Environmental Science and Technology, Volume 42, Pages 7032-7037. |
| Authors: Hauschild, M.Z., Huijbregts, M., Jolliet, O., Macleod, M., Margni, M., van de Meent, D., Rosenbaum, R.K., McKone, T.E. | Type: Journal Article |
| Report number: | Year: 2008 |
| Title: International consensus model for comparative assessment of chemical emissions in LCA | Published in: International Academy for Production Engineering (CIRP) 15th International Conference on Life Cycle Engineering. |
| Authors: Hauschild, M.Z., Bachman, T.M., Huijbregts, M., Jolliet, O., Kohler, A., Larsen, H.F., Magni, M., McKone, T.E., Macleod, M., van de Meent, D., Schuhmacher, M., Rosenbaum, R.K. | Type: |
| Abstract: Under the UNEP-SETAC Life Cycle Initiative the six most commonly used characterization models for toxic impacts from chemicals were compared and harmonized through a sequence of workshops removing differences which were unintentional or unnecessary. A parsimonious (as simple as possible but as complex as needed) and transparent consensus model, USEtox, was created producing characterization factors that fall within the range of factors from the harmonised existing characterisation models. The USEtox model together with factors for several thousand substances are currently under review to form the basis of the recommendations from the UNEP-SETAC Life Cycle Initiative in this field. | |
| Report number: LBNL-2373E | Year: 2008 |
| Title: Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment | Published in: Submitted to SETAC Journal. |
| Authors: Cowan, C.E., McLachlan, M.S., Arnot, J.A, Macleod, M., McKone, T.E., Wania, F | Type: Journal Article |
| Abstract: 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: • 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. • 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. • 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. • 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. It is possible to have confidence in the predictions of many of the existing models because of their fundamental physical and chemical mechanistic underpinnings and the extensive work already done to compare model predictions and empirical observations. The working group recommends that modeling tools be applied for benchmarking PBT/POPs according to exposure-to-emissions relationships, and that modeling tools be used to interpret emissions and monitoring data. The further development of models that couple fate, long-range transport, and bioaccumulation should be fostered, especially models that will allow time trends to be scientifically addressed in the risk profile. | |
| Report number: LBNL-376E | Year: 2008 |
| Title: Effectiveness of Urban Shelter-in-Place III: Urban Districts | Published in: Building Simulation, Volume 1, Pages 144-157. |
| Authors: Chan, W.R., Nazaroff, W.W., Price, P.N., Gadgil, A.J. | Type: Journal Article |
| Report number: LBNL-60750 | Year: 2007 |
| Title: Using biomarkers to inform cumulative risk assessment | Published in: Environmental Health Perspectives, Volume 115, Pages 833-840. |
| Authors: Ryan, P.B., Burke, T.A., Cohen Hubal, E.A., Cura, J.J., McKone, T.E. | Type: Journal Article |
| Report number: LBNL-60699 | Year: 2007 |
| Title: Merging models and biomonitoring data to characterize sources and pathways of human exposure to organophosphorous pesticides in the Salinas Valley of California | Published in: Environmental Science and Technology, Volume 41, Pages 3233-3240. |
| Authors: McKone, T.E., Castorina, R., Kuwabara, Y., Harnly, M.E., Eskenazi, B., Bradman, A. | Type: Journal Article |
| Abstract: By drawing on human biomonitoring data and limited environmental samples together with outputs from the CalTOX multimedia, multipathway source-to-dose model, we characterize cumulative intake of organophosphorous (OP) pesticides in an agricultural region of California. We assemble regional OP pesticide use, environmental sampling, and biological tissue monitoring data for a large and geographically dispersed population cohort of 592 pregnant Latina women in California (the CHAMACOS cohort). We then use CalTOX with regional pesticide usage data to estimate the magnitude and uncertainty of exposure and intake from local sources. We combine model estimates of intake from local sources with food intake based on national residue data to estimate for the CHAMACOS cohort cumulative median OP intake, which corresponds to expected levels of urinary dialkylphosphate (DAP) metabolite excretion for this cohort. From these results we develop premises about relative contributions from different sources and pathways of exposure. We evaluate these premises by comparing the magnitude and variation of DAPs in the CHAMACOS cohort with the whole U.S. population using data from the National Health and Nutrition Evaluation Survey (NHANES). This comparison supports the premise that in both populations diet is the common and dominant exposure pathway. Both the model results and biomarker comparison supports the observation that the CHAMACOS population has a statistically significant higher intake of OP pesticides that appears as an almost constant additional dose among all participants. We attribute the magnitude and small variance of this intake to non-dietary exposure in residences from local sources. | |
| Report number: | Year: 2007 |
| Title: Exploring relationships between outdoor air particulate-associated polycyclic aromatic hydrocarbon and PM2.5: A case study of benzo(a)pyrene in California metropolitan regions | Published in: Atmospheric Environment, Volume 41, Pages 5659–5672. |
| Authors: Lobscheid, A.G., McKone, T.E., Vallero, D. | Type: Journal Article |
| Report number: | Year: 2007 |
| Title: Controlled Exposure Chamber Study of Uptake and Clearance of Airborne Polycyclic Aromatic Hydrocarbons by Wheat Grain | Published in: Environmental Science and Technology, Volume 41, Pages 7934 - 7940. |
| Authors: Kobayashi, R., Cahill, T.M., Okamoto, R.A., Maddalena, R.L., Kado, N.Y. | Type: Journal Article |
| Report number: | Year: 2007 |
| Title: Inflammatory response of lung cells exposed to whole, filtered, and hydrocarbon denuded diesel exhaust | Published in: Chemosphere, Volume 70, Pages 13-19. |
| Authors: Holder, A.H., Lucas, D., Goth-Goldstein, R., Koshland, C.P. | Type: Journal Article |
| Report number: LBNL-62107 | Year: 2007 |
| Title: Effectiveness of urban shelter-in-place. II: Residential Districts | Published in: Atmospheric Environment, Volume 41, Pages 7082-7095. |
| Authors: Chan, W.R., Nazaroff, W.W., Price, P.N., Gadgil, A.J. | Type: Journal Article |
| Report number: LBNL-61686 | Year: 2007 |
| Title: Effectiveness of Urban Shelter-in-Place I: Idealized Conditions | Published in: Atmospheric Environment, Volume 41, Pages 4962-4976 . |
| Authors: Chan, W.R., Nazaroff, W.W., Price, P. N., Gadgil, A.J. | Type: Journal Article |
| Report number: LBNL-59781 | Year: 2006 |
| Title: Indoor Residential Chemical Exposures as Risk Factors for Asthma and Allergy in Infants and Children: A Review | Published in: Proceedings of Healthy Buildings 2006 Conference, Volume 1, Pages 151-156. |
| Authors: Mendell, M. | Type: Conference Proceedings |
| Abstract: Most research into effects of residential indoor air exposures on asthma and allergies has focused on exposures to biologic allergens, moisture and mold, endotoxin, or combustion byproducts. This paper briefly reviews reported findings on associations of asthma or allergy in infants or children with risk factors related to indoor chemical emissions from residential materials or surface coatings. Associations, some strong (e.g., odds ratios up to 13), were reported. The most frequently identified risk factors were formaldehyde, aromatic organic compounds such as toluene and benzene, plastic materials and plasticizers, and recent painting. Exposures and consequent effects from indoor sources may be exacerbated by decreased ventilation. Identified risk factors may be proxies for correlated exposures. Findings suggest the frequent occurrence of important but preventable effects on asthma and allergy in infants and children worldwide from modern residential building materials and coatings. | |
| Report number: LBNL-60369 | Year: 2006 |
| Title: Integrated Environmental Assessment Part III: Exposure Assessment | Published in: |
| Authors: McKone, T.E., Small, M.J. | Type: Report |
| Report number: LBNL-60802 | Year: 2006 |
| Title: Inhalation intake of ambient air pollution in California's South Coast Air Basin | Published in: Atmospheric Environment, Volume 40, Pages 4381-4392. |
| Authors: Marshall, J.D., Granvold, P.W., Hoats, A.S., McKone, T.E., Deakine, E., Nazaroff, W. | Type: Journal Article |
| Abstract: Reliable estimates of inhalation intake of air pollution and its distribution among a specified population are important for environmental epidemiology, health risk assessment, urban planning, and environmental policy. We computed distributional characteristics of the inhalation intake of five pollutants for a group of ~25,000 people (~29,000 person-days) living in California's South Coast Air Basin. Our approach incorporates four main inputs: temporally resolved information about people's location (latitude and longitude), microenvironment, and activity level; temporally and spatially explicit model determinations of ambient concentrations; stochastically determined microenvironmental adjustment factors relating the exposure concentration to the ambient concentration; and, age-, gender-, and activity-specific breathing rates. Our study is restricted to pollutants of outdoor origin, i.e. it does not incorporate intake in a microenvironment from direct emissions into that microenvironment. Median estimated inhalation intake rates ( g d-1) are 53 for benzene, 5.1 for 1,3-butadiene, 8.7 10-4 for hexavalent chromium in fine particulate matter (Cr-PM2.5), 30 for diesel fine particulate matter (DPM2.5), and 68 for ozone. For the four primary pollutants studied, estimated median intake rates are higher for non-whites and for individuals in low-income households than for the population as a whole. For ozone, a secondary pollutant, the reverse is true. Accounting for microenvironmental adjustment factors, population mobility, and temporal correlations between pollutant concentrations and breathing rates affects the estimated inhalation intake by 40% on average. The approach presented here could be extended to quantify the impact on intakes and intake distributions of proposed changes in emissions, air quality, and urban infrastructure. | |
| Report number: LBNL-57769 | Year: 2006 |
| Title: Prospective Hazard Assessment and Sensitivity Analysis for Buckminsterfullerene in the Environment | Published in: |
| Authors: Maddalena, R. L., MacLeod, M., McKone, T.E., Sohn, M.D. | Type: Report |
| Report number: LBNL-59669 | Year: 2006 |
| Title: Public health benefits of end-use electrical energy efficiency in California. | Published in: |
| Authors: Lobscheid, A.B., McKone, T.E. | Type: Report |
| Report number: LBNL-60312 | Year: 2006 |
| Title: Field Measurement of polycyclic aromatic hydrocarbons in wheat grain grown in Sacramento and San Joaquin Valleys, California | Published in: |
| Authors: Kobayashi, R., Okamoto, R.A., Maddalena, R. L., Kado, N.Y. | Type: Report |
| Abstract: Wheat grain samples from five different counties in California were analyzed for 2- to 6-ring polycyclic aromatic hydrocarbons (PAHs). PAH profiles were similar for all the samples, but concentrations differed by location. Major PAHs present in the California grain were mainly gas-phase PAHs. Diesel- fueled harvesting operations did not appear to contribute to observed PAH concentration in grain. PAHs in grain most likely came from atmospheric deposition. | |
| Report number: LBNL-60313 | Year: 2006 |
| Title: The role of multimedia mass balance models for assessing the effects of volatile organic compound emissions on urban air quality | Published in: Atmospheric Environment, Volume 40, Pages 2986-2994. |
| Authors: Foster, K.L., Sharpe, S., Webster, E., Mackay, D., Maddalena, R. L. | Type: Journal Article |
| Report number: LBNL-55457 | Year: 2005 |
| Title: Can Fuzzy Logic Bring Complex Problems into Focus? | Published in: Environmental Science and Technology, Volume 39, Pages 42A-47A. |
| Authors: McKone, T.E., Deshpande, A.W. | Type: Journal Article |
| Abstract: You and a friend walk outside on an April morning. You announce that the weather is "mild". Your friend declares it "cold". Who is wrong? Or are you both right? We all recognize that language can be imprecise and that words such as cold, hot, or mild do not have well-defined boundaries. In 1965, Lotfi Zadeh introduced fuzzy logic as a means of processing data by extending classical set theory to handle partial membership1. Classical set theory deals with sets that are "crisp" in the sense that members are either in or out according to rules of binary logic. For example the apple in the basket is Red OR Not Red (binary logic). Some of the apples could be categorized as Red AND Not Red (fuzzy logic). Many of the concepts that we deal with in everyday life and in fields such environmental health involve factors that defy classification into "crisp" sets-safe, harmful, acceptable, unacceptable, etc. A classic example is when a regulator, who after she carefully explains the result of a detailed quantitative risk assessment to a community group is then asked "But are we safe?" In this case, "safe," defies crisp classification because it is a multivariate state with gradations, that vary among different individuals and groups. Fuzzy logic has become a common way of dealing with information in a number of fields, such as control theory, smart machines, investment analysis and so on. But the application of fuzzy sets can and has been extended to environmental science and policy. For anyone who has worked on health and environmental issues, it becomes immediately obvious that we deal constantly with fuzzy concepts-hazard, acceptable, safe, etc. Even concepts such as carcinogen and neurotoxin define fuzzy sets whose members are selected by experts who review and make judgments on conflicting toxicology or epidemiology. In spite of their relevance and early efforts to promote their use in risk assessment2, fuzzy logic applications are still rare in risk assessment or other environmental assessments. In this paper we consider whether and how fuzzy logic and fuzzy arithmetic apply to risk assessment and environmental policy. We use a case study assessment of water quality in the Ganga river of India to illustrate this evaluation. Our goal is to consider whether and how much this approach can be applied more broadly for environmental assessments. | |
| Report number: LBNL-57938 | Year: 2005 |
| Title: Pollution, Soil | Published in: Encylopedia of Toxicology, Pages 489-495. |
| Authors: McKone, T.E., Wexler, Philip | Type: Book Section |
| Abstract: Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative mix of these components determines both the value of the soil for agricultural and other human uses and the extent to which chemicals or biological organisms added to soil will be transported and/or transformed within the soil. Soils are characteristically heterogeneous. A trench dug into the soil zone typically reveals several horizontal layers having different colors and textures. These layers and their generic structure are illustrated in Figure 1. These multiple layers are often divided into three major horizons-(1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, is below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. | |
| Report number: LBNL-55458 | Year: 2005 |
| Title: Inhalation of motor vehicle emissions: Effects of urban population and area | Published in: Atmospheric Environment, Volume 39, Pages 283-295. |
| Authors: Marshall, J.D., McKone, T.E., Deakin, E.A., Nazaroff, W.W. | Type: Journal Article |
| Abstract: Urban population density can influence transportation demand, as expressed through average daily vehicle-kilometers traveled per capita (VKT). In turn, changes in transportation demand influence total passenger vehicle emissions. Population density can also influence the fraction of total emissions that are inhaled by the exposed urban population. Equations are presented that describe these relationships for an idealized representation of an urban area. Using analytic solutions to these equations, we investigate the effect of three changes in urban population and urban land area (infill, sprawl and constant-density growth) on per capita inhalation intake of primary pollutants from passenger vehicles. The magnitude of these effects depends on density-emissions elasticity (Ee), a normalized derivative relating change in population density to change in vehicle emissions. For example, if urban population increases, per capita intake is less with infill development than with constant-density growth if Ee is less than -0.5, while for Ee greater than -0.5 the reverse is true. | |
| Report number: LBNL-50588 | Year: 2004 |
| Title: Reconstructing Population Exposures from Dose Biomarkers: Inhalation of Trichloroethylene (TCE) as a Case Study | Published in: Journal of Exposure Analysis and Environmental Epidemiology, Volume 14, Pages 204-213. |
| Authors: Sohn, M.D., TE McKone, JN Blancato | Type: Journal Article |
| Abstract: Physiologically based pharmacokinetic (PBPK) modeling is a well-established toxicological tool designed to relate exposure to a target tissue dose. The emergence of federal and state programs for environmental health tracking and the availability of exposure monitoring through biomarkers creates the opportunity to apply PBPK models to estimate exposures to environmental contaminants from urine, blood, and tissue samples. However, reconstructing exposures for large populations is complicated by often having too few biomarker samples, large uncertainties about exposures, and large inter-individual variability. In this paper we use an illustrative case study to identify some of these difficulties and for a process for confronting them by reconstructing population-scale exposures using Bayesian inference. The application consists of interpreting biomarker data from eight adult males with controlled exposures to trichloroethylene (TCE) as if the biomarkers were random samples from a large population with unknown exposure conditions. The TCE concentrations in blood from the individuals fell into two distinctly different groups even though the individuals were simultaneously in a single exposure chamber. We successfully reconstructed the exposure scenarios for both subgroups -- although the reconstruction of one subgroup is different than what is believed to be the true experimental conditions. We were however unable to predict with high certainty the concentration of TCE in air. | |
| Report number: LBNL-52144 | Year: 2004 |
| Title: Passive measurement of nitrogen oxides to assess traffic-related pollutant exposure for the East Bay Children's Respiratory Health Study | Published in: Atmospheric Environment, Volume 38, Pages 393-403. |
| Authors: Singer, B.C., Hodgson, A., Hotchi, T., Kim, J.J. | Type: Journal Article |
| Report number: LBNL-54916 | Year: 2004 |
| Title: Methods to determine the size distribution of airborne rhinovirus | Published in: |
| Authors: Russell, M., Goth-Goldstein, R., Apte, M G., Fisk, W.J. | Type: Report |
| Abstract: About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Prior research has demonstrated that rhinovirus infections can be transmitted via person-to-person contact and via inhalation of infectious aerosols. Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. To detect airborne HRV, we developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine the assay detection limit of 5 fg of HRV RNA with a linear range over 10,000-fold. This assay was used to quantify the size distribution of an artificially-produced HRV aerosol captured with an Andersen six-stage cascade impactor. In future studies, we hope to use the methods developed here to characterize the size distribution of naturally occurring viral-aerosols. | |
| Report number: LBNL-56097 | Year: 2004 |
| Title: Using Image and Curve Registration for Measuring the Goodness of Fit of Spatial and Temporal Predictions | Published in: Biometrics, Volume 60, Pages 954-964. |
| Authors: Reilly, C., Price, P. N., Gelman, A., Sandgathe, S.A. | Type: Journal Article |
| Report number: LBNL-52471 | Year: 2004 |
| Title: Inhalation of Hazardous Air Pollutants from Environmental Tobacco Smoke in US Residences | Published in: Journal of Exposure Analysis and Environmental Epidemiology, Volume 14, Pages S71-77. |
| Authors: Nazaroff, W., Singer, B.C. | Type: Journal Article |
| Abstract: In the United States, 48 million adults smoke 3.5-5 1011 cigarettes per year. Many cigarettes are smoked in private residences causing regular environmental tobacco smoke (ETS) exposure to roughly 31million nonsmokers (11% of the US population), including 16 million juveniles. (Upper bound estimates are 53 million exposed nonsmokers including 28 million juveniles.) ETS contains many chemical species whose industrial emissions are regulated by the US federal government as hazardous air pollutants (HAPs). In this paper, average daily residential exposures to and intakes of 16 HAPs in ETS are estimated for US nonsmokers who live with smokers. The evaluation is based on material-balance modeling; utilizes published data on smoking habits, demographics, and housing; and incorporates newly reported exposure-relevant emission factors. The ratio of estimated average exposure concentrations to reference concentrations is close to or greater than one for acrolein, acetaldehyde, 1,3-butadiene and formaldehyde, indicating potential for concern regarding noncancer health effects from chronic exposures. In addition, lifetime cancer risks from residential ETS exposure are estimated to be substantial (~ 2-500 per million) for each of five known or probable human carcinogens: acetaldehyde, formaldehyde, benzene, acrylonitrile, and 1,3-butadiene. Cumulative population intakes from residential ETS are compared for six key compounds against ambient sources of exposure. ETS is found to be a dominant source of environmental inhalation intake for acrylonitrile and 1,3-butadiene. It is an important cause of intake for acetaldehyde, acrolein, and formaldehyde, and a significant contributor to intake for benzene. | |
| Report number: LBNL-52203 | Year: 2004 |
| Title: Standardized Approach for Developing Probabilistic Exposure Factor Distributions | Published in: Risk Analysis, Volume 24, Pages 1185-1199. |
| Authors: Maddalena, R.L., McKone, T.E., Sohn, M.D. | Type: Journal Article |
| Abstract: The effectiveness of a probabilistic risk assessment (PRA) depends critically on the quality of input information that is available to the risk assessor and specifically on the probabilistic exposure factor distributions that are developed and used in the exposure and risk models. Deriving probabilistic distributions for model inputs can be time consuming and subjective. The absence of a standard approach for developing these distributions can result in PRAs that are inconsistent and difficult to review by regulatory agencies. We present an approach that reduces subjectivity in the distribution development process without limiting the flexibility needed to prepare relevant PRAs. The approach requires two steps. First, we analyze data pooled at a population scale to (i) identify the most robust demographic variables within the population for a given exposure factor, (ii) partition the population data into subsets based on these variables, and (iii) construct archetypal distributions for each subpopulation. Second, we sample from these archetypal distributions according to site- or scenario-specific conditions to simulate exposure factor values and use these values to construct the scenario-specific input distribution. It is envisaged that the archetypal distributions from step 1 will be generally applicable so risk assessors will not have to repeatedly collect and analyze raw data for each new assessment. We demonstrate the approach for two commonly used exposure factors -- body weight (BW) and exposure duration (ED) -- using data for the U.S. population. For these factors we provide a first set of subpopulation based archetypal distributions along with methodology for using these distributions to construct relevant scenario-specific probabilistic exposure factor distributions. | |
| Report number: LBNL-52369 | Year: 2004 |
| Title: Dependence of Intake Fraction on Release Location in a Multimedia Framework - A Case Study of Four Contaminants in North America | Published in: Journal of Industrial Ecology, Volume 8, Pages 89-102(14). |
| Authors: MacLeod, M.J., Bennet, D.H., Perem, M., Maddalena, R.L., McKone, T.E., Mackay, D. | Type: Journal Article |
| Abstract: The extent of human exposure to persistent anthropogenic environmental contaminants is a complex function of the amount of chemical emitted, its physico-chemical properties and reactivity, the nature of the environment, and the characteristics of the pathways for human exposure, such as inhalation, intake of food and water and dermal contact. For some chemicals, the location of emissions relative to areas of high population density or intense food production may also be an important factor. The relative importance of these variables is explored using the regionally segmented BETR North America contaminant fate model and data for food production patterns and population density for North America. The model is applied to four contaminants emitted to air: benzene, carbon tetrachloride, benzo[a]pyrene and 2,3,7,8- tetrachlorodibenzo dioxin. The total continental intake fraction (iF), relating exposure quantity to emission quantity, is employed as a metric for assessing population exposure to environmental contaminants. The results show that the use of continentally averaged parameters for population density and food production provides an accurate estimate of the median of iF calculated for emissions in individual regions, however iF can range from this median by up to 3 orders of magnitude, especially for chemicals transferred to humans through the food pathway. The location of population relative to food production and emissions of chemicals are important variables that should be considered in assessing the public health implications of chemical emissions. | |
| Report number: LBNL-53245 | Year: 2004 |
| Title: Overall multi-media persistence as an indicator of potential for population-level intake of environmental contaminants | Published in: Environmental Toxicology and Chemistry, Volume 23, Pages 2465-2472. |
| Authors: MacLeod, Matthew | Type: Journal Article |
| Abstract: Although it is intuitively apparent that population-level exposure to contaminants dispersed in the environment must related to the persistence of the contaminant, there has been little effort to formally quantify this link. In this paper we investigate the relationship between overall persistence in a multimedia environment and the population-level exposure as expressed by intake fraction (iF), which is the cumulative fraction of chemical emitted to the environment that is taken up by members of the population. We first confirm that for any given chemical contaminant and emission scenario the definition of iF implies that it is directly proportional to the overall multi-media persistence, POV. We show that the proportionality constant has dimensions of time and represents the characteristic time for population intake (CTI) of the chemical from the environment. We then apply the CalTOX fate and exposure model to explore how POV and CTI combine to determine the magnitude of iF. We find that CTI has a narrow range of possible values relative to POV across multiple chemicals and emissions scenarios. We use data from the Canadian Environmental Protection Act Priority Substance List (PSL1) Assessments to show that exposure assessments based on empirical observation are consistent with interpretations from the model. The characteristic time for intake along different dominant exposure pathways is discussed. Results indicate that POV derived from screening-level assessments of persistence, bioaccumulation potential, and toxicity (PBT) is a useful indicator of the potential for population-level exposure. | |
| Report number: LBNL-55586 | Year: 2004 |
| Title: Traffic-related Air Pollution near Busy Road: The East Bay Children's Respiratory Health Study | Published in: American Journal of Respiratory and Critical Care Medicine, Volume 170, Pages 520-526. |
| Authors: Kim, J.J., Smorodinsky, S., Lipsett, M., Hodgson, A., Singer, B.C., Ostro, B. | Type: Journal Article |
| Abstract: Recent studies, primarily in Europe, have reported associations between respiratory symptoms and residential proximity to traffic; however, few have measured traffic pollutants or provided information about local air quality. We conducted a school-based, crosssectional study in the San Francisco Bay Area in 2001. Information on current bronchitis symptoms and asthma, home environment, and demographics was obtained by parental questionnaire (n = 1,109). Concentrations of traffic pollutants (particulate matter, black carbon, total nitrogen oxides [NOX], and nitrogen dioxide [NO2]) were measured at 10 school sites during several seasons. Although pollutant concentrations were relatively low, we observed differences in concentrations between schools nearby versus those more distant (or upwind) from major roads. Using a two-stage multiple-logistic regression model, we found associations between respiratory symptoms and traffic-related pollutants. Among those living at their current residence for at least 1 year, the adjusted odds ratio for asthma in relationship to an interquartile difference in NOX was 1.07 (95% confidence interval, 1.00–1.14). Thus, we found spatial variability in traffic pollutants and associated differences in respiratory symptoms in a region with good air quality. Our findings support the hypothesis that traffic-related pollution is associated with respiratory symptoms in children. | |
| Report number: LBNL-51882 | Year: 2003 |
| Title: Is there a "forest filter effect" for organic pollutants? | Published in: Stochastic Environmental Research and Risk Assessment, Volume 17, Pages 231-234. |
| Authors: Maddalena, R.L., McKone, T.E. | Type: Journal Article |
| Abstract: No abstract available | |
| Report number: LBNL-52156 | Year: 2003 |
| Title: On the influence of forests on the overall fate of semivolatile organic contaminants | Published in: Stochastic Environmental Research and Risk Assessment, Volume 17, Pages 256-259. |
| Authors: MacLeod, M.J. | Type: Journal Article |
| Abstract: Convincing experimental evidence exists that the presence of vegetation, especially forest canopies, enhances scavenging of semi-volatile organic chemicals (SVOCs) from the atmosphere and increases their depositional flux to the terrestrial surface relative to deposition to bare soil. Evidence from several modeling studies indicates that gaseous deposition to vegetation is the most efficient scavenging pathway, and, due to interactions between gas-particle partitioning in the atmosphere and resistance to diffusion through the cuticle of plants, that pathway is available for SVOCs with Log Koa between 7 and 11 and Log Kaw > -6. However, for enhanced scavenging by vegetation to influence the overall regional and global fate of SVOCs, it must represent a process that is competitive with the other fate and transport processes in the ecological system under consideration. The key question in evaluating the importance of the "Forest Filter Effect" on the regional and global fate of SVOCs is: Does scavenging from the atmosphere by vegetation have a significant influence on the inter-media partitioning, long-range transport and/or environmental persistence of SVOCs? Based on evidence presented below from the CoZMo-POP model and supported by results from other models that together represent our current state of knowledge, the Forest Filter Effect does not exert a controlling influence over regional or global contaminant fate and transport. | |
| Report number: LBNL-51905 | Year: 2003 |
| Title: Traditional risk factor study (TRiFS): Preliminary report on risk factor prevalence and population attributable fraction estimates for breast cancer in Marin County, California | Published in: |
| Authors: Erdmann, C.A., Satariano, W.A., Chen, Y.Q. | Type: Report |
| Abstract: The objective of the Traditional Risk Factor Study (TRiFS) was to describe female breast cancer risk factor distributions in Marin County, California by using previously collected, individual-level data. The Marin County breast cancer risk factor distributions were compared with those of the other California counties and the State. Prevalence estimates for traditional breast cancer risk factors (e.g., age at menarche, family history, and age at first birth) were computed using data from the Marin County Breast Cancer Study of Adolescent Risk Factors (ARFS) and the California Health Interview Survey (CHIS). A reference set of relative risk values for the breast cancer risk factors of interest was assembled from published sources. Using the prevalence estimates along with these relative risk values, population attributable fractions were calculated for selected breast cancer risk factors and combinations of these factors. Approximately 84% of Marin County women were exposed to at least one of the following five breast cancer risk factors: earlier age at menarche, later age at 1st birth or nulliparity family history, later age at menopause, and/or higher postmenopausal body mass index (BMI). The results suggest that 50% of Marin County's breast cancer cases would be avoided if the traditional breast cancer risk factors considered in these analyses were eliminated. Later age at first birth and nulliparity after age 30 alone appear to account for about one-third of breast cancer cases in Marin County. | |
| Report number: LBNL-52484 | Year: 2003 |
| Title: Breast Cancer and Personal Environmental Risk Factors in Marin County -- Pilot Study | Published in: |
| Authors: Erdmann, C.A., Farren, G., Baltzell, K., Chew, T., Clarkson, C., Fleshman, R., Leary, C., Mizroch, M., Orenstein, F., Russell, ML., Souders-Mason, V., Wrensch, M. | Type: Report |
| Abstract: The purpose of the Personal Environmental Risk Factor Study (PERFS) pilot project was to develop methodologies and a questionnaire for a future population-based case-control study to investigate the role of selected environmental exposures in breast cancer development. Identification of etiologically relevant exposures during a period of potential vulnerability proximate to disease onset offers the possibility of clinical disease prevention even when disease initiation may have already occurred many years earlier. Certain personal environmental agents or combinations of agents may influence disease promotion. Therefore, this pilot study focused on exposures that occurred during the ten-year period prior to diagnosis for cases and the last ten years for controls, rather than more historic exposures. For this pilot study, we used a community-based research approach. In our collaborative efforts, community members participated with academic researchers in all phases of the research, including research question identification, study design, development of research tools, development of the human subjects protocol, and report writing. Community member inclusion was based upon the concept that community participation could improve the relevance of scientific studies and ultimate success of the research by encouraging an ongoing dialogue between community members and academic representatives. Early activities of this project focused on the collection of input from the community regarding the possible role of environmental factors in the incidence of breast cancer in Marin County. The intent was to inform the scientists of community concerns, enhance the research team's understanding of the community being studied, and provide interested community members with a better understanding of the strengths and weaknesses of traditional research methods through active participation in the research process. This pilot study identified specific testable hypotheses through review of the literature and consultation with relevant experts and the affected community. Initially, the study was to focus on modifiable personal environmental exposures that are associated with breast tumor promotion and higher socioeconomic status (SES). However, little information was available in the scientific literature regarding the putative mechanism by which some of the suspected environmental factors may act (i.e., initiator vs. promoter). Likewise, little is known about the distribution of personal environmental risk factors by socioeconomic status. Therefore, tumor promotion involvement and association with SES were not very useful as selection criteria, and selection of topics was based primarily on published scientific findings of human studies and community input. This study was approved by the Institutional Review Boards at the University of California at San Francisco (Committee on Human Research) and at the University of California at Berkeley (Committee for the Protection of Human Subjects). | |
| Report number: LBNL-49574 | Year: 2002 |
| Title: Method for measuring the size distribution of airborne rhinovirus | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 40-45. |
| Authors: Russell, M.L., Goth-Goldstein, R., Apte, M.G., Fisk, W.J. | Type: Conference Proceedings |
| Abstract: About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor. | |
| Report number: LBNL-50850 | Year: 2002 |
| Title: Development and evaluation of a personal particulate organic and mass sampler | Published in: Environmental Science and Technology, Volume 36, Pages 5205-5210. |
| Authors: Pang, Y., Gundel, L.A., Larson, T., Finn, D., Liu, L.J. Sally , Claiborn, C.S. | Type: Journal Article |
| Abstract: Accurate measurement of personal exposure to particulate matter and its constituents requires samplers that are accurate, compact, lightweight, inexpensive and convenient to use. The Personal Particulate Organic and Mass Sampler (PPOMS) has been developed to meet these criteria. The PPOMS uses activated carbon- impregnated foam as a combined 2.5-?m size-selective inlet and denuder for assessment of fine particle mass and organic carbon. Proof of the PPOMS concept has been established by comparing mass and organic carbon in particles collected with collocated samplers in Seattle, at a central outdoor site and in residences. Daily particulate mass concentrations averaged 10.0?5.2, 12.0?5.3, and 11.2?5.1 ?g m-3 for the Federal Reference Method, the Harvard Personal Exposure Monitor, and the PPOMS, respectively, for 10 24-h sampling periods. During a series of PM2.5 indoor organic carbon (OC) measurements from single quartz filters, the apparent indoor OC averaged 7.7?0.8 ?g of C m-3, which was close to the indoor PM2.5 mass from collocated Teflon filters (7.3?2.3 ?g of C m-3), indicating the presence of a large positive OC artifact. In collocated measurements, the PPOMS eliminated this artifact just as well as the Integrated Gas and Particle Sampler that incorporated a macroreticular poly(styrene- divinylbenzene) (XAD-4) resin- coated denuder, yielding OC concentrations of 2.5 ? 0.4 and 2.4 ? 1.0 ?g C m-3, respectively. Thermal analysis for OC indicated that the indoor positive artifact was due to adsorption of gas-phase SVOC. This study shows that the PPOMS design provides a 2.5-?m size-selective inlet that also prevents the adsorption of gas-phase semi-volatile organic compounds onto quartz filters, thus eliminating the filter positive artifact. The PPOMS meets a significant current challenge for indoor and personal sampling of particulate organic carbon. The PPOMS design can also simplify accurate ambient sampling for PM2.5. | |
| Report number: LBNL-48401 | Year: 2002 |
| Title: Evaluation of gastrointestinal solubilization of petroleum hydrocarbon residues in soil using an in vitro physiologically- based model | Published in: Environmental Science & Technology, Volume 36, Pages 1281-1286. |
| Authors: Holman, H.Y., Goth-Goldstein, R., Aston, D., Mao, Y., Kengsoontra, J. | Type: Journal Article |
| Abstract: No Abstract available | |
| Report number: LBNL-50479 | Year: 2002 |
| Title: 7H-Benzo[c]fluorene DNA adduct formation in different human cells in culture | Published in: |
| Authors: Goth-Goldstein, R., Russell, M.L. , Parimoo, B. , Weyand, E.H. | Type: Report |
| Abstract: 7H-Benzo[c]fluorene (B[c]F) has been known for a long time as a component of complex mixtures such as coal tar or cigarette smoke. B[c]F has been identified recently as a potent lung tumorigen and a major DNA adduct-forming component of coal tar. We have investigated if human cells have the ability to form B[c]F:DNA adducts as detected in lungs of mice treated with B[c]F. MCF7 (human breast cancer), HepG2 (hepatoma) and Caco-2 (colon adenocarcinoma) cells were treated with increasing concentrations (0.2 -- 10 *g/ml) of B[c]F for 20 hours. Adduct formation was evaluated using 32P-postlabeling. A dose response in DNA adduct formation was detected in all three cell lines. In MCF7 and HepG2 cells, two adducts were detected, one of them corresponded to an adduct observed in the lungs of mice treated with B[c]F. This adduct is derived from 3-hydroxy B[c]F while the second, slower migrating adduct, appears to be unique to human cells. In contrast, Caco-2 cells formed at least four adducts. Two of the three most predominant adducts correspond to the two adducts observed in MCF7 and HepG2 cells while the additional predominate and a minor adduct are derived from 3,4-dihydrodiol B[c]F. The adducts derived from 3,4- dihydrodiol B[c]F are similar to those observed in mouse lung and skin. The detection of B[c]F:DNA adducts clearly demonstrates that human cells have the capacity to metabolically activate B[c]F to derivatives that covalently modify DNA. Similarities in the types of B[c]F:DNA adducts detected also demonstrates that B[c]F activation is similar in both human cells and mouse tissue. | |
| Report number: LBNL-51005 | Year: 2002 |
| Title: An instrument for automated simultaneous measurements of ammonia and nitric acid in indoor and outdoor air | Published in: |
| Authors: Fischer, M., Littlejohn D., Lunden, M., Gundel, L.A., Dod, R., Brown N.J. | Type: Report |
| Abstract: No Abstract available. | |
| Report number: LBNL-48453 | Year: 2002 |
| Title: Polycyclic aromatic hydrocarbons in a bioassay-directed fractionated extract of PM10 collected in Sao Paulo, Brazil | Published in: Atmospheric Environment, Volume 36, Pages 307-314. |
| Authors: De Martinis, B.S., Okamoto, R.A., Kado, N.Y., Gundel, L.A., Carvalho, L.R.F. | Type: Journal Article |
| Abstract: No Abstract available | |
| Report number: LBNL-51334 | Year: 2002 |
| Title: Assessing cumulative organophosphate pesticide exposure and risk among pregnant women living in an agricultural community | Published in: Environmental Health Perspectives, Volume 111, Pages 1640-1648. |
| Authors: Castorina, R., Bradman, A., McKone, T.E. | Type: Journal Article |
| Abstract: Approximately 225,000 kilograms of organophosphate (OP) pesticides are used annually in California's Salinas Valley, which is intensively farmed for vegetables and fruit. These activities have raised concerns about pesticide exposures to area residents. As part of a prospective cohort study, we collected three spot urine samples from 462 pregnant women and analyzed them for six dialkyl phosphate metabolites. Based on these urinary metabolite concentrations, we estimated OP pesticide doses with deterministic steady-state models using two methods: the first method assumed the pesticide metabolites were attributable entirely to a single diethyl or dimethyl OP pesticide; the second method adapted U.S. EPA draft guidelines for cumulative risk assessment to estimate dose from a mixture of OP pesticides that share a common mechanism of toxicity. We used pesticide use reporting data for the Salinas Valley to quantify the likely mixture to which the women were exposed. Based on average OP pesticide dose estimates that assumed exposure to a single OP pesticide (Method 1), between 0% and 36.0% of study participants' exposures exceeded the U.S. EPA oral benchmark dose10 (BMD10) divided by a 100-fold uncertainty factor, depending on the assumption made about the parent compound. These BMD10 values were derived from studies of brain cholinesterase inhibition in rats. 14.7% of the participants' average cumulative OP pesticide dose estimates (Method 2) exceeded the BMD10 of the selected index chemical divided by a 100- fold uncertainty factor, regardless of index chemical chosen. An uncertainty analysis of the pesticide mixture parameter suggests that this point estimate could range from 1%-38%. Because our reference value (BMD10/100) may not account for the special sensitivity of the developing fetus, this research points to the need for modeling approaches to estimate fetal exposures and assess risk from prenatal OP pesticide exposure. | |
| Report number: LBNL-50378 | Year: 2002 |
| Title: Addressing locally grown foods in cumulative exposure assessments | Published in: Journal of Exposure Analysis and Environmental Epidemiology, Volume 14, Pages 60-73. |
| Authors: Bodnar, A.B., Maddalena, R.L. , McKone, T.E. | Type: Journal Article |
| Abstract: Both laboratory and field studies confirm the importance of vegetation for scavenging semi-volatile 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. Exposure calculations based on published concentration data for foods indicate that the potential intake through ingestion is up to 1000 times that of inhalation for several persistent SVOCs. However, little information exists on the source-to-dietary intake linkage for SVOC's. 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 the characteristic travel distance (CTD) and available data within the CalTOX multimedia model framework to assess the contribution of local food markets to the fraction of cumulative food intake that is attributable to local sources. For a set of three representative multimedia SVOCs- benzo(a)pyrene, fluoranthene, and 2,3,7,8-TCDD, we explore the contribution of airborne SVOC's to cumulative uptake through the local food consumption pathway. We use the population based intake fraction (iF) to determine how SVOC intake varies among food commodities and compares to inhalation. The approach presented here provides a useful framework and starting point for source-to-intake assessments for the air-to-dietary exposure pathway. | |
| Report number: LBNL-53458 | Year: 2002 |
| Title: A fugacity-based indoor residential pesticide fate model | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 261-266. |
| Authors: Bennett, D.H., Furtaw, E.J., McKone, T.E. | Type: Conference Proceedings |
| Abstract: Dermal and non-dietary pathways are potentially significant exposure pathways to pesticides used in residences. Exposure pathways include dermal contact with residues on surfaces, ingestion from hand- and object-to-mouth activities, and absorption of pesticides into food. A limited amount of data has been collected on pesticide concentrations in various residential compartments following an application. But models are needed to interpret this data and make predictions about other pesticides based on chemical properties. In this paper, we propose a mass-balance compartment model based on fugacity principles. We include air (both gas phase and aerosols), carpet, smooth flooring, and walls as model compartments. Pesticide concentrations on furniture and toys, and in food, are being added to the model as data becomes available. We determine the compartmental fugacity capacity and mass transfer-rate coefficient for wallboard as an example. We also present the framework and equations needed for a dynamic mass- balance model. | |
| Report number: LBNL-48254 | Year: 2001 |
| Title: The Human Toxicity Potential and a Strategy for Evaluating Model Performance in Life-Cycle Impact Assessment | Published in: International Journal of Life-Cycle Assessment, Volume 6, Pages 106-109. |
| Authors: McKone, T.E., E.G. Hertwich | Type: Journal Article |
| Report number: LBNL-47713 | Year: 2001 |
| Title: The National Human Activity Pattern Survey (NHAPS): A resource for assessing exposure to environmental pollutants | Published in: Journal of Exposure Analysis and Environmental Epidemiology, Volume 11, Pages 231-252. |
| Authors: Klepeis, N.E., Nelson, W.C., Ott, W.R., Robinson, J.P. , Tsang, A.M. , Switzer, P., Behar, J.V. , Hern, S.C. , Engelmann, W.H. | Type: Journal Article |
| Report number: LBNL-46084 | Year: 2000 |
| Title: Managing the health impacts of waste incineration | Published in: Environmental Science & Technology, Volume 34, Pages 380A-387A. |
| Authors: McKone, T.E., Hammond, S.K. | Type: Journal Article |
| Report number: LBNL-43717 | Year: 1999 |
| Title: The rise of exposure assessment among the risk sciences: an evaluation through case studies | Published in: Inhalation Toxicology, Volume 11, Pages 101-112. |
| Authors: McKone, T.E. | Type: Journal Article |
| Report number: LBNL-43604 | Year: 1999 |
| Title: Development and Evaluation of Probability Density Functions for a Set of Human Exposure Factors | Published in: |
| Authors: Maddalena, R. L., T.E. McKone, A. Bodnar, J. Jacobson | Type: Report |
| Report number: LBNL-43752 | Year: 1999 |
| Title: In vitro model for intestinal uptake of benzo(a)pyrene | Published in: |
| Authors: Goth-Goldstein, R., Holman, H.-Y., Russell, M. | Type: Report |
| Report number: LBNL-43716 | Year: 1999 |
| Title: A multimedia, multiple pathway exposure assessment of atrazine: the impact of age differentiated exposure including joint uncertainty and variability | Published in: Reliability Engineering and System Safety, Volume 63, Pages 185-198. |
| Authors: Bennett, D.H., W.E. Kastenberg, T.E. McKone | Type: Journal Article |
| Report number: | Year: 1998 |
| Title: A Report on the Workshop on Improving Exposure Analysis for DOE Sites September 1996, San Francisco, CA | Published in: Journal of Exposure Analysis and Environmental Epidemiology, Volume 8, Pages 3-7. |
| Authors: Daisey, J.M. | Type: Journal Article |
| Report number: | Year: 1997 |
| Title: Soil Contamination and Human Exposure: A Comprehensive Assessment Framework | Published in: International Journal of Toxicology, Volume 16, Pages 319-337. |
| Authors: McKone, T.E., R.L. Maddalena | Type: Journal Article |
| Report number: LBL-37760 | Year: 1997 |
| Title: Environmental health risk assessment for tritium releases at the national tritium labeling facility at Lawrence Berkeley National Laboratory | Published in: |
| Authors: McKone, T.E., K.P. Brand, C. Shan | Type: Report |
| Report number: | Year: 1997 |
| Title: Predicting the Bioconcentration of Organic Chemicals from Soil or Air into Plants Using Quantitative Structure Activity Relationships | Published in: Environmental Toxicology and Chemistry, Volume 16, Pages 2448-2456. |
| Authors: Dowdy, D.L, McKone, T.E. | Type: Journal Article |
| Report number: LBNL-40838 | Year: 1997 |
| Title: Population based exposure assessment methodology for carbon monoxide: Development of a Carbon Monoxide Passive Sampler and Occupational Dosimeter | Published in: |
| Authors: Apte, M.G. | Type: Report |
| Report number: | Year: 1996 |
| Title: Interspecies extrapolation of physiological pharmacokinetic parameter distributions | Published in: Risk Analysis, Volume 16, Pages 741-754. |
| Authors: Watanabe, K., Bois, F. | Type: Journal Article |
| Report number: | Year: 1996 |
| Title: Absorption rate vs. exposure: which is more useful for bioequivalence testing | Published in: Pharmaceutical Research, Volume 13, Pages 453-456. |
| Authors: Tozer, T. N., Bois, F., Hauck, W. H., Chen, M.L., Williams, R. | Type: Journal Article |
| Report number: | Year: 1996 |
| Title: Overview of the risk analysis approach and terminology: The merging of science, judgment, and values," Food Control,7(2): 69-76 | Published in: Food Control, Volume 7, Pages 69-76. |
| Authors: McKone, T. E. | Type: Journal Article |
| Report number: LBL-37984 | Year: 1996 |
| Title: Gas and particle sampling of airborne polycyclic aromatic compounds | Published in: Polycyclic Aromatic Compounds, Volume 9, Pages 67-73. |
| Authors: Lane, D., Gundel, L. | Type: Journal Article |
| Report number: LBNL-39846 | Year: 1996 |
| Title: Development and commercialization of a carbon monoxide occupational dosimeter: Progress Report to ERLTR | Published in: |
| Authors: Gundel, L.A., Apte, M.G., Goldstein, M., Traynor, G.W., Oum, M., Helfman, W.B., Chang, G.M. | Type: Report |
| Report number: | Year: 1996 |
| Title: Physiological pharmacokinetic analysis using population modeling and informative prior distributions | Published in: Journal of the American Statistical Association, Volume 91, Pages 1400-1412. |
| Authors: Gelman, A., Bois, F., Jiang, J. | Type: Journal Article |
| Report number: | Year: 1996 |
| Title: The Use of the Molecular Connectivity Index for Estimating Biotransfer Factors | Published in: Environmental Science & Technology, Volume 30, Pages 984-989. |
| Authors: Dowdy, D., McKone, T. E., Hsieh, D. P. H. | Type: Journal Article |
| Report number: | Year: 1996 |
| Title: Population toxicokinetics of benzene. Environmental Health Perspectives | Published in: Environmental Health Perspectives, Volume Suppl 6, Pages 1405-1411. |
| Authors: Bois, F., Jackson, E., Pekari, K., Smith, M. | Type: Journal Article |
| Report number: | Year: 1996 |
| Title: Population toxicokinetics of tetrachloroethylene | Published in: Archives of Toxicology, Volume 70, Pages 347-355. |
| Authors: Bois, F., Gelman, A., Jiang, J., Maszle, D., Zeise, L., Alexeef, G. | Type: Journal Article |
| Report number: | Year: 1995 |
| Title: Statistical and regulatory considerations for multiple measures in bioequivalence testing | Published in: Clinical Research and Regulatory Affairs, Volume 12, Pages 249-265. |
| Authors: Hauck, W., Hyslop, T., Anderson, S., Bois, F., Tozer, T. | Type: Journal Article |
| Report number: | Year: 1995 |
| Title: Human interindividual variability in metabolism and risk: the example of 4-aminobiphenyl | Published in: Risk Analysis, Volume 15, Pages 205-213. |
| Authors: Bois, F., Krowech, G., Zeise, L. | Type: Journal Article |
| Report number: LBNL-2385E | Year: 2009 |
| Title: Bioaccumulation Potential Of Air Contaminants: Combining Biological Allometry, Chemical Equilibrium And Mass-Balances To Predict Accumulation Of Air Pollutants In Various Mammals | Published in: Submitted to Journal of Toxicology and Applied Pharmacology. |
| Authors: Veltman, K., McKone, T.E., Huijbregts, M., Hendricks, A.J. | Type: Journal Article |
| Abstract: In the present study we develop and test a uniform model intended for single compartment analysis in the context of human and environmental risk assessment of airborne contaminants. The new aspects of the model are the integration of biological allometry with fugacity-based mass-balance theory to describe exchange of contaminants with air. The developed model is applicable to various mammalian species and a range of chemicals, while requiring few and typically well-known input parameters, such as the adult mass and composition of the species, and the octanol-water and air-water partition coefficient of the chemical. Accumulation of organic chemicals is typically considered to be a function of the chemical affinity for lipid components in tissues. Here, we use a generic description of chemical affinity for neutral and polar lipids and proteins to estimate blood-air partition coefficients (Kba) and tissue-air partition coefficients (Kta) for various mammals. This provides a more accurate prediction of blood-air partition coefficients, as proteins make up a large fraction of total blood components. The results show that 75% of the modeled inhalation and exhalation rate constants are within a factor of 2 from independent empirical values for humans, rats and mice, and 87% of the predicted blood-air partition coefficients are within a factor of 5 from empirical data. At steady-state, the bioaccumulation potential of air pollutants is shown to be mainly a function of the tissue-air partition coefficient and the biotransformation capacity of the species and depends weakly on the ventilation rate and the cardiac output of mammals. | |
| Report number: LBNL-2370E | Year: 2009 |
| Title: CKow – A More Transparent and Reliable Model for Chemical Transfer to Meat and Milk | Published in: Submitted to Environmental Science and Technology. |
| Authors: Rosenbaum, R.K., McKone, T.E., Jolliet, O. | Type: Journal Article |
| Abstract: The objective of this study is to increase the understanding and transparency of chemical biotransfer modeling into meat and milk and explicitly confront the uncertainties in exposure assessments of chemicals that require such estimates. In cumulative exposure assessments that include food pathways, much of the overall uncertainty is attributable to the estimation of transfer into biota and through food webs. Currently, the most commonly used meat and milk-biotransfer models date back two decades and, in spite of their widespread use in multimedia exposure models few attempts have been made to advance or improve the outdated and highly uncertain Kow regressions used in these models. Furthermore, in the range of Kow where meat and milk become the dominant human exposure pathways, these models often provide unrealistic rates and do not reflect properly the transfer dynamics. To address these issues, we developed a dynamic three-compartment cow model (called CKow), distinguishing lactating and non-lactating cows. For chemicals without available overall removal rates in the cow, a correlation is derived from measured values reported in the literature to predict this parameter from Kow. Results on carry over rates (COR) and biotransfer factors (BTF) demonstrate that a steady-state ratio between animal intake and meat concentrations is almost never reached. For meat, empirical data collected on short term experiments need to be adjusted to provide estimates of average longer term behaviors. The performance of the new model in matching measurements is improved relative to existing models—thus reducing uncertainty. The CKow model is straight forward to apply at steady state for milk and dynamically for realistic exposure durations for meat COR. | |
| Report number: LBNL-2518E | Year: 2009 |
| Title: Mass Transport within Soils | Published in: Environmental Mass Transfer Handbook. |
| Authors: McKone, T.E., Thibodeaux, L.J., Mackay, D. | Type: Book Section |
| Report number: LBNL-2284E | Year: 2009 |
| Title: Efficiency of clay-TiO2 nanocomposites on the photocatalytic elimination of a model hydrophobic air pollutant | Published in: Submitted to Environmental Science & Technology. |
| Authors: Daria Kibanova, Javiera Cervini-Silva, Hugo Destaillats | Type: Journal Article |
| Abstract: Clay-supported TiO2 photocatalysts can potentially improve the performance of air treatment technologies via enhanced adsorption and reactivity of target volatile organic compounds (VOCs). In this study, a bench-top photocatalytic flow reactor was used to evaluate the efficiency of hectorite-TiO2 and kaolinite-TiO2, two novel composite materials synthesized in our laboratory. Toluene, a model hydrophobic VOC and a common indoor air pollutant, was introduced in the air stream at realistic concentrations, and reacted under UVA (λmax = 365 nm) or UVC (λmax = 254 nm) irradiation. The UVC lamp generated secondary emission at 185 nm, leading to the formation of ozone and other short-lived reactive species. Performance of clay-TiO2 composites was compared with that of pure TiO2 (Degussa P25), and with UV irradiation in the absence of photocatalyst under identical conditions. Films of clay-TiO2 composites and of P25 were prepared by a dip-coating method on the surface of Raschigrings, which were placed inside the flow reactor. An upstream toluene concentration of~170 ppbv was generated by diluting a constant flow of toluene vapor from a diffusion source with dry air, or with humid air at 10, 33 and 66 % relative humidity (RH). Toluene concentrations were determined by collecting Tenax-TA ® sorbent tubes downstream of the reactor, with subsequent thermal desorption – GC/MS analysis. The fraction of toluene removed, %R, and the reaction rate, Tr, were calculated for each experimental condition from the concentration changes measured with and without UV irradiation. Use of UVC light (UV/TiO2/O3) led to overall higher reactivity, which can be partially attributed to the contribution of gas phase reactions by short-lived radical species. When the reaction rate was normalized to the light irradiance, Tr/Iλ, the UV/TiO2 reaction under UVA irradiation was more efficient for samples with a higher content of TiO2 (P25 and Hecto-TiO2), but not for Kao-TiO2. In all cases, reaction rates peaked at 10% RH, with Tr values between 10 and 50% higher than those measured under dry air. However, a net inhibition was observed as RH increased to 33% and 66%, indicating that water molecules competed effectively with toluene for reactive surface sites and limited the overall photocatalytic conversion. Compared to P25, inhibition by co-adsorbed water was less significant for Kao-TiO2 samples, but was more dramatic for Hecto-TiO2 due to the high water uptake capacity of hectorite. | |
| Report number: LBNL-2404E | Year: 2009 |
| Title: Evaluating indoor exposure modeling alternatives for LCA: A case study in the vehicle repair industry | Published in: Environmental Science and Technology, Volume 43, Pages 5804-5810. |
| Authors: Demou, E., Hellweg, S., Wilson, M.P. , Hammond, K.S., McKone, T.E. | Type: Journal Article |
| Abstract: We evaluated three exposure models with data obtained from measurements among workers who use “aerosol” solvent products in the vehicle repair industry and with field experiments using these products to simulate the same exposure conditions. The three exposure models were the: 1) homogeneously-mixed-one-box model, 2) multi-zone model, and 3) eddy-diffusion model. Temporally differentiated real-time breathing zone 3 volatile organic compound (VOC) concentration measurements, integrated far-field area samples, and simulated experiments were used in estimating parameters, such as emission rates, diffusivity, and near-field dimensions. We assessed differences in model input requirements and their efficacy for predictive modeling. The One-box model was not able to resemble the temporal profile of exposure concentrations, but it performed well concerning time-weighted exposure over extended time periods. However, this model required an adjustment for spatial concentration gradients. Multi-zone models and diffusion-models may solve this problem. However, we found that the reliable use of both these models requires extensive field data to appropriately define pivotal parameters such as diffusivity or near-field dimensions. We conclude that it is difficult to apply these models for predicting VOC exposures in the workplace. However, for comparative exposure scenarios in life-cycle assessment they may be useful. | |
| Report number: LBNL-2420E | Year: 2008 |
| Title: Using Information on Uncertainty to Improve Environmental Fate Modeling: A Case Study on DDT | Published in: Environmental Science and Technology, Volume 43, Pages 128-134. |
| Authors: Schenker, U., Scheringer, M., Sohn, M.D., Maddalena, R.L., McKone, T.E., Hungerbühler, K. | Type: Journal Article |
| Abstract: Present and future concentrations of DDT in the environment are calculated with the global multi-media model CliMoChem. Monte Carlo simulations are used to assess the importance of uncertainties in substance property data, emission rates, and environmental parameters for model results. Uncertainties in the model results, expressed as 95% confidence intervals of DDT concentrations in various environmental media, in different geographical locations, and at different points in time are typically between one and two orders of magnitude. An analysis of rank correlations between model inputs and predicted DDT concentrations indicates that emission estimates and degradation rate constants, in particular in the atmosphere, are the most influential model inputs. For DDT levels in the Arctic, temperature dependencies of substance properties are also influential parameters. A Bayesian Monte Carlo approach is used to update uncertain model inputs based on measurements of DDT in the field. The updating procedure suggests a lower value for half-life in air and a reduced range of uncertainty for KOW of DDT. As could be expected, the Bayesian updating yields model results that are closer to observations, and model uncertainties have decreased. The combined sensitivity analysis and Bayesian Monte Carlo approach provide new insight into important processes that govern the global fate and persistence of DDT in the environment. | |
| Report number: LBNL-2383E | Year: 2008 |
| Title: Population Physiologically-Based Pharmacokinetic Modeling for the Human Lactational Transfer of PCB 153 with Consideration of Worldwide Human Biomonitoring Results | Published in: Environmental Health Perspectives, Volume 116, Pages 1629-1634. |
| Authors: Redding, L.E., Sohn, M.D., McKone, T.E., Wang, S.L., Hsieh, D.P.H., Yang, R.S.H. | Type: Journal Article |
| Abstract: We developed a physiologically based pharmacokinetic model of PCB 153 in women, and predict its transfer via lactation to infants. The model is the first human, population-scale lactational model for PCB 153. Data in the literature provided estimates for model development and for performance assessment. Physiological parameters were taken from a cohort in Taiwan and from reference values in the literature. We estimated partition coefficients based on chemical structure and the lipid content in various body tissues. Using exposure data in Japan, we predicted acquired body burden of PCB 153 at an average childbearing age of 25 years and compare predictions to measurements from studies in multiple countries. Forward-model predictions agree well with human biomonitoring measurements, as represented by summary statistics and uncertainty estimates. The model successfully describes the range of possible PCB 153 dispositions in maternal milk, suggesting a promising option for back estimating doses for various populations. One example of reverse dosimetry modeling was attempted using our PBPK model for possible exposure scenarios in Canadian Inuits who had the highest level of PCB 153 in their milk in the world. | |
| Report number: LBNL-87E | Year: 2008 |
| Title: Exposure Information in Environmental Health Research: Current Opportunities and Future Directions for Particulate Matter, Ozone, and Toxic Air Pollutants | Published in: Journal of Exposure Science and Environmental Epidemiology, Volume doi: 10.1038/jes.2008.3 In Press. |
| Authors: McKone, T.E., Ryan, P.B., Ozkaynak, H. | Type: Journal Article |
| Report number: LBNL-2283E | Year: 2008 |
| Title: Indoor pollutants emitted by electronic office equipment | Published in: Indoor Air 2008. |
| Authors: Randy L. Maddalena, Hugo Destaillats, Marion L. Russell, Alfred T. Hodgson, Thomas E. McKone | Type: Conference Proceedings |
| Report number: LBNL-514E | Year: 2008 |
| Title: Exploring relationships between outdoor air particulate-associated polycyclic aromatic hydrocarbon and PM2.5: A case study of benzo(a)pyrene in California metropolitan regions | Published in: Atmospheric Environment, Volume 41, Pages 5659-5672. |
| Authors: Lobscheid, A.B., McKone, T.E., Valleroc, D.A. | Type: Journal Article |
| Abstract: Polycyclic aromatic hydrocarbons (PAHs) and particulate matter (PM) are co-pollutants emitted as by-products of combustion processes. Convincing evidence exists for PAHs as a primary toxic component of fine PM (PM2.5). Because PM2.5 is listed by the US EPA as a "Criteria Pollutant," it is monitored regularly at sites nationwide. In contrast, very limited data is available on measured ambient air concentrations of PAHs. However, between 1999-2001, ambient air concentrations of PM2.5 and benzo(a)pyrene (BaP) are available for California locations. We use multivariate linear regression models (MLRMs) to predict ambient air levels of BaP in four air basins based on reported PM2.5 concentrations and spatial, temporal and meteorological variables as variates. We obtain an R2 ranging from 0.57-0.72 among these basins. Significant variables (p<0.05) include the average daily PM2.5 concentration, wind speed, temperature and relative humidity, and the coastal distance as well as season, and holiday or weekend. Combining the data from all sites and using only these variables to estimate ambient BaP levels, we obtain an R2 of 0.55. These R2-values, combined with analysis of the residual error and cross validation using the PRESS-statistic, demonstrate the potential of our method to estimate reported outdoor air PAH exposure levels in metropolitan regions. These MLRMs provide a first step towards relating outdoor ambient PM2.5 and PAH concentrations for epidemiological studies when PAH measurements are unavailable, or limited in spatial coverage, based on publicly available meteorological and PM2.5 data. | |
| Report number: | Year: 2008 |
| Title: Polycyclic aromatic hydrocarbons in edible grain: A pilot study of agricultural crops as a human exposure pathway for environmental contaminants using wheat as a model crop | Published in: Environmental Research, Volume 107, Pages 145-151. |
| Authors: Kobayashi, R., Okamoto, R.A., Maddalena, R.L., Kado, N.Y. | Type: Journal Article |
| Report number: LBNL-748E | Year: 2008 |
| Title: Synthesis of Hectorite-TiO2 and Kaolinite-TiO2 Nanocomposites with Photocatalytic Activity for the Degradation of Model Air Pollutants | Published in: Applied Clay Science, Volume doi:10.1016/j.clay.2008.03.009. In press. |
| Authors: Kibanova, D., Trejo, M., Destaillats, H., Cervini-Silva, J. | Type: Journal Article |
| Report number: LBNL-2375E | Year: 2008 |
| Title: Integrating Human Indoor Air Pollutant Exposure within Life Cycle Impact Assessment | Published in: Environmental Science and Technology, Volume 43, Pages 1670-1679. |
| Authors: Hellweg, S., Demou, E., Bruzzi, R., Meijer, A., Rosenbaum, R.K. , Huijbregts, M.A.J. , McKone, T.E. | Type: Journal Article |
| Abstract: 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. | |
| Report number: LBNL-62082 | Year: 2008 |
| Title: Indoor pollutants emitted by office equipment: A review of reported data and information needs | Published in: Atmospheric Environment, Volume 42, Pages 1371-1388. |
| Authors: Destaillats, H., Maddalena, R.L., Singer, B.C., Hodgson, A.T., McKone, T.E. | Type: Journal Article |
| Report number: LBNL-59303 | Year: 2007 |
| Title: Sorption of organic gases in residential rooms | Published in: Atmospheric Environment, Volume 41, Pages 3251-3265. |
| Authors: Singer, B.C., Hodgson, A.T., Hotchi, T., Ming, K.Y., Sextro, R.G., Wood, E. E., Brown, N.J. | Type: Journal Article |
| Report number: | Year: 2007 |
| Title: Plant Uptake of Organic Pollutants from Soil: Bioconcentration Estimates Based on Models and Experiments-Review | Published in: Environmental Toxicology and Chemistry, Volume 26, Pages 2494-504. |
| Authors: McKone, T.E., Maddalena, R.L. | Type: Journal Article |
| Report number: LBNL-60273 | Year: 2007 |
| Title: Plant Uptake of Organic Pollutants from Soil: Model Performance Evaluation | Published in: Environmental Toxicology and Chemistry , Volume 26, Pages 2494–2504. |
| Authors: Maddalena, R. L., MacLeod, M., mckone T.E. | Type: Journal Article |
| Report number: LBNL-60749 | Year: 2006 |
| Title: Dose-response modeling for life cycle impact assessment, Findings of the Portland Review Workshop | Published in: International Journal of Life Cycle Assessment, Volume 11, Pages 209-212. |
| Authors: Mckone, T.E., Kyle, A. D., Jolliet, O., Olsen, S. I., Hauschild, M. | Type: Journal Article |
| Abstract: The United Nations Environment Program (UNEP)/SETAC Life Cycle Initiative aims at putting life cycle thinking into practice and at improving the supporting tools for this process through better data and indicators. The initiative has thus launched three programs with associated working groups (see http://www.uneptie.org/pc/sustain/lcinitiative/). The Task Force on Toxic Impacts was established under the Life Cycle Impact Assessment (LCIA) program to establish recommended practice and guidance for use in human toxicity, ecosystem toxicity, and related categories with direct effects on human health and ecosystem health. During the 2004 SETAC Europe meeting in Prague, an international group of LCIA practitioners initiated activities of the LCIA Task Force 3 (TF3) to address exposure and toxicity with the goal of establishing guidance for LCIA. As an adjunct activity of the 2004 SETAC World Congress in Portland, Oregon, TF3 members organized a workshop to review existing proposals on human toxicity indicators for LCIA. The particular focus of this workshop was on options regarding dose-effect response and severity. The review workshop consisted of formal presentations of approaches followed by a review discussion performed by a panel of internationally recognized dose-response modeling experts. This workshop was organized by Thomas McKone of the University of California, Berkeley and Michael Hauschild and Stig Irving Olsen from the Danish Technical University in Denmark. Amy Kyle of the University of California, Berkeley, facilitated the workshop. This workshop involved several internationally recognized dose-response modeling experts as well as LCIA specialists (see footnote for the full list). The product of this workshop is a set of short recommendations that are being transmitted via this report. | |
| Report number: LBNL-57770 | Year: 2006 |
| Title: Background Air Component of Measured Vegetation/Soil Bioconcentration Ratios | Published in: |
| Authors: Maddalena, R. L., Kulakow, P. | Type: Report |
| Abstract: Soil-to-plant biotransfer plays a critical role in assessing both human and ecological risks at phytoremediation sites and in establishing risk-based screening levels at hydrocarbon impacted exploration and production sites. The plant/soil bioconcentration ratios (BCRs) that are used to estimate exposure concentrations in crops and feed are based on empirical relationships developed from measured chemical concentrations in plants and soil. These measurements often neglect the contribution of background air to observed concentrations in vegetation. As a result, plant/soil BCRs and the models that use BCRs may overstate the contribution of soil to contaminant concentrations in vegetation. To explore this issue we combine two separate but related studies of polycyclic aromatic hydrocarbon (PAH) uptake into vegetation. Results from a controlled exposure chamber study provide details on direct (soil-plant) and indirect (soil-air-plant) uptake pathways while results from a cooperative phytoremediation study yield relevant field measurements with a range of soil concentrations. Mass transfer at the air/plant interface is fast relative to uptake from soil, so atmospheric pollutants can contribute to above ground vegetation concentrations. Atmospheric pollutant concentrations place a limit on the concentrations in soil below which soil-to-plant transfers can no longer be reliably determined. We find that even low background atmospheric concentrations can influence soil-to-plant BCR measurements, particularly for the more lipophilic chemicals. In addition to the field data and laboratory study, we use a multimedia mass balance approach with illustrative atmospheric PAH concentrations to estimate the limit on soil concentrations where transfer to above ground vegetation can be observed. By screening out lower soil concentration data we provide an alternate regression to estimate soil-to-vegetation BCRs for PAHs. | |
| Report number: LBNL-57854 | Year: 2006 |
| Title: A Mass Balance for Mercury in the San Francisco Bay Area | Published in: Environmental Science and Technology, Volume 39, Pages 6721-6729. |
| Authors: MacLeod, M., Mckone, T.E., Mackay, D. | Type: Journal Article |
| Abstract: We develop and illustrate a general regional multi-species model that describes the fate and transport of mercury in three forms, elemental, divalent, and methylated, in a generic regional environment including air, soil, vegetation, water and sediment. The objectives of the model are to describes the fate of the three forms of mercury in the environment and determine the dominant physical sinks that remove mercury from the system. Chemical transformations between the three groups of mercury species are modeled by assuming constant ratios of species concentrations in individual environmental media. We illustrate and evaluate the model with an application to describe the fate and transport of mercury in the San Francisco Bay Area of California. The model successfully rationalizes the identified sources with observed concentrations of total mercury and methyl mercury in the San Francisco Bay Estuary. The mass balance provided by the model indicates that continental and global background sources control mercury concentrations in the atmosphere but loadings to water in the San Francisco Bay estuary are dominated by runoff from the Central Valley catchment and re-mobilization of contaminated sediments deposited during past mining activities. The model suggests that the response time of mercury concentrations in the San Francisco Bay estuary to changes in loadings is long, of the order of 50 years. | |
| Report number: LBNL-55458 | Year: 2005 |
| Title: Inhalation of motor vehicle emissions: Effects of urban population and area | Published in: Atmospheric Environment, Volume 39, Pages 283-295. |
| Authors: Marshall, J.D., McKone, T.E., Deakin, E.A., Nazaroff, W.W. | Type: Journal Article |
| Abstract: Urban population density can influence transportation demand, as expressed through average daily vehicle-kilometers traveled per capita (VKT). In turn, changes in transportation demand influence total passenger vehicle emissions. Population density can also influence the fraction of total emissions that are inhaled by the exposed urban population. Equations are presented that describe these relationships for an idealized representation of an urban area. Using analytic solutions to these equations, we investigate the effect of three changes in urban population and urban land area (infill, sprawl and constant-density growth) on per capita inhalation intake of primary pollutants from passenger vehicles. The magnitude of these effects depends on density-emissions elasticity (Ee), a normalized derivative relating change in population density to change in vehicle emissions. For example, if urban population increases, per capita intake is less with infill development than with constant-density growth if Ee is less than -0.5, while for Ee greater than -0.5 the reverse is true. | |
| Report number: LBNL-56801 | Year: 2005 |
| Title: Modeling transport and deposition of level 1 substances to the great lakes | Published in: |
| Authors: MacLeod, M., Riley, W.J., McKone T.E. | Type: Report |
| Abstract: Mass balance modeling of 18 chemicals that are representative of Level I substances identified under the Great Lakes Binational Toxics Strategy and targeted for virtual elimination from the Great Lakes has been carried out using a suite of models. The goals of this work are to assess the potential of each substance for transport from local and distant sources and subsequent deposition to the surface of the Great Lakes, and to make estimates of the contribution to total atmospheric loading attributable to emissions at different locations in North America and globally. Models are applied to analyze the efficiency of long-range transport and deposition of Level I substances to the Great Lakes (the Great Lakes transfer efficiency, GLTE). The GLTE is the percentage of chemical released to air in a source region that is expected to be deposited from the atmosphere to the surface waters of the Great Lakes. Modeling at the North American and global scale is carried out using two models based on the Berkeley-Trent (BETR) contaminant fate modeling framework: BETR North America and BETR Global. Model-based assessments of Great Lakes transfer efficiency are used to group the substances according to the spatial scale of emission likely to impact the Lakes: (1) Local or regional scale substances: Dieldrin, Aldrin and benzo[a]pyrene, (2) Continental scale: chlordane, 2,3,7,8-tetrachlordibenzodioxin, p,p-DDT, toxaphene, octachlorostyrene and mirex, (3) Hemispheric scale: PCBs, (4) Global scale: hexachlorobenzene and a-HCH. Using available emissions estimates and the models, the contribution of emissions of Level I substances in different regions of North America and globally to the total atmospheric loading to the Lakes has been estimated. These estimates are subject to large uncertainties, most notably because of uncertainties in emission scenarios, degradation rates of the substances in environmental media. However, model uncertainties due to simplified descriptions of exchange processes between environmental media and environmental conditions also contribute to overall uncertainty in the assessment. Mass balance calculations are presented for seven PCB congeners and toxaphene at the North American spatial scale and for the PCBs and a-HCH at the global scale. Comparison of cumulative historical emissions scenarios with estimated emissions in the year 2000 indicates that relative contributions from sources outside North America are increasing as sources are curtailed in the United States and Canada. In particular, Eastern Europe appears to be becoming a relatively more important source to the Lakes. However, under all emission scenarios considered, the majority of PCB deposition to the Lakes from the atmosphere is attributable to sources in North America. The mass balance models presented in this report provide a quantitative framework for assembling the best available information about properties, sources, partitioning, degradation, transport, and the ultimate fate of persistent organic substances. The uncertainties associated with these assessments are believed to be dominated by uncertainties in emission estimates and environmental degradation rates for the Level I substances and further research should be focused on better characterization of emissions and studies of degradation reactions in various environmental media. Given these uncertainties in the overall mass balance calculations, further model-based studies should concentrate on assessing the influence of more refined descriptions of fate and transport processes within the existing model frameworks, and not on increasing the spatial and temporal resolution of the existing models. Once our understanding of the basic mechanisms resulting in deposition to the Lakes has improved sufficiently, research should focus on spatial and temporal scaling issues. | |
| Report number: LBNL-57704 | Year: 2005 |
| Title: Assessing the Influence of Climate Variability on Atmospheric Concentrations of Persistent Organic Pollutants Using a Global-Scale Mass Balance Model (BETR-Global) | Published in: Environmental Science & Technology, Volume 39, Pages 6749-6756. |
| Authors: MacLeod, M., Riley, W.J., McKone, T. E. | Type: Journal Article |
| Report number: LBNL-54848 | Year: 2005 |
| Title: Comparing estimates of persistence and long-range transport potential among multimedia models | Published in: Environmental Science & Technology, Volume 39, Pages 1932 -1942. |
| Authors: MacLeod, M., McKone, T. E., Fenner, K., Scheringer, M., Matthies, M., Stroebe, M., Beyer, A., Bonnell, M., Le Gall, A.C., Klasmeier, J., Mackay, D., van de Meent, D., Pennington, D. , Scharenberg, B., Suzuki, N., Wania, F. | Type: Journal Article |
| Report number: LBNL-54849 | Year: 2005 |
| Title: Identifying POP-like behavior in screening assessments of organic chemicals | Published in: Environmental Science & Technology, Volume 40, Pages 53-60. |
| Authors: MacLeod, M., McKone, T. E. | Type: Journal Article |
| Report number: LBNL-54148 | Year: 2004 |
| Title: BETR-World: A geographically explicit model of chemical fate - application to transport of a-HCH to the Artic | Published in: Environmental Pollution, Volume 128, Pages 223-240. |
| Authors: Toose, L., Woodfine, D.G., MacLeod, M., Mackay, D., Gouin, J. | Type: Journal Article |
| Abstract: The Berkeley–Trent (BETR)-World model, a 25 compartment, geographically explicit fugacity-based model is described and applied to evaluate the transport of chemicals from temperate source regions to receptor regions (such as the Arctic). The model was parameterized using GIS and an array of digital data on weather, oceans, freshwater, vegetation and geo-political boundaries. This version of the BETR model framework includes modi.cation of atmospheric degradation rates by seasonally variable hydroxyl radical concentrations and temperature. Degradation rates in all other compartments vary with seasonally changing temperature. Deposition to the deep ocean has been included as a loss mechanism. A case study was undertaken for a-HCH. Dynamic emission scenarios were estimated for each of the 25 regions. Predicted environmental concentrations showed good agreement with measured values for the northern regions in air, and fresh and oceanic water and with the results from a previous model of global chemical fate. Potential for long-range transport and deposition to the Arctic region was assessed using a Transfer Efficiency combined with estimated emissions. European regions and the Orient including China have a high potential to contribute a-HCH contamination in the Arctic due to high rates of emission in these regions despite low Transfer Efficiencies. Sensitivity analyses reveal that the performance and reliability of the model is strongly in.uenced by parameters controlling degradation rates. | |
| Report number: LBNL-54147 | Year: 2004 |
| Title: Modelling the fate of persistent organic pollutants in Europe: Parameterisation of a gridded distribution model | Published in: Environmental Pollution, Volume 128, Pages 251-261. |
| Authors: Prevedouros, K., MacLeod, M., Jones, K.C., Sweetman, A.J. | Type: Journal Article |
| Abstract: A regionally segmented multimedia fate model for the European continent is described together with an illustrative steady-state case study examining the fate of g-HCH (lindane) based on 1998 emission data. The study builds on the regionally segmented BETR North America model structure and describes the regional segmentation and parameterisation for Europe. The European continent is described by a 5 degrees x 5 degrees grid, leading to 50 regions together with four perimetric boxes representing regions bufferring the European environment. Each zone comprises seven compartments including; upper and lower atmosphere, soil, vegetation, fresh water and sediment and coastal water. Inter-regions flows of air and water are described, exploiting information originating from GISdatabases and other georeferenced data. The model is primarily designed to describe the fate of Persistent Organic Pollutants (POPs) within the European environment by examining chemical partitioning and degradation in each region, and inter-region transport either under steady-state conditions or fully dynamically. A test case scenario is presented which examines the fate of estimated spatially resolved atmospheric emissions of lindane throughout Europe within the lower atmosphere and surface soil compartments. In accordance with the predominant wind direction in Europe, the model predicts high concentrations close to the major sources as well as towards Central and Northeast regions. Elevated soil concentrations in Scandinavian soils provide further evidence of the potential of increased scavenging by forests and subsequent accumulation by organic-rich terrestrial surfaces. Initial model predictions have revealed a factor of 5-10 underestimation of lindane concentrations in the atmosphere. This is explained by an underestimation of source strength and/or an underestimation of European background levels. The model presented can further be used to predict deposition fluxes and chemical inventories, and it can also be adapted to provide characteristic travel distances and overall environmental persistence, which can be compared with other long-range transport prediction methods. | |
| Report number: LBNL-54630 | Year: 2004 |
| Title: Applications of contaminant fate and bioaccumulation models in assessing ecological risks of chemicals: A case study for gasoline hydrocarbons | Published in: Environmental Science & Technology, Volume 38, Pages 6225 -6233. |
| Authors: MacLeod, M.J., McKone,T.E., Foster, K.L., Maddalena, R.L., Parkerton, T.F., Mackay, D. | Type: Journal Article |
| Abstract: Mass balance models of chemical fate and transport can be applied in ecological risk assessments for quantitative estimation of concentrations in air, water, soil and sediment. These concentrations can, in turn, be used to estimate organism exposures and ultimately internal tissue concentrations that can be compared to mode-of-action-based critical body residues that correspond to toxic effects. From this comparison, risks to the exposed organism can be evaluated. To illustrate the practical utility of fate models in ecological risk assessments of commercial products, the EQC model and a simple screening level biouptake model including three organisms, (a bird, a mammal and a fish) is applied to gasoline. In this analysis, gasoline is divided into 24 components or "blocks" with similar environmental fate properties that are assumed to elicit ecotoxicity via a narcotic mode of action. Results demonstrate that differences in chemical properties and mode of entry into the environment lead to profound differences in the efficiency of transport from emission to target biota. We discuss the implications of these results and insights gained into the regional fate and ecological risks associated with gasoline. This approach is particularly suitable for assessing mixtures of components that have similar modes of action. We conclude that the model-based methodologies presented are widely applicable for screening level ecological risk assessments that support effective chemicals management. | |
| Report number: LBNL-54149 | Year: 2004 |
| Title: Modeling transport and deposition of contaminants to ecosystems of concern: A case study for the Laurentian Great Lakes | Published in: Environmental Pollution, Volume 128, Pages 241-250. |
| Authors: MacLeod, M., Mackay, D. | Type: Journal Article |
| Abstract: Transfer Efficiency (TE) is introduced as a model output that can be used to characterize the relative ability of chemicals to be transported in the environment and deposited to specific target ecosystems. We illustrate this concept by applying the Berkeley-Trent North American contaminant fate model (BETR North America) to identify organic chemicals with properties that result in efficient atmospheric transport and deposition to the Laurentian Great Lakes. By systematically applying the model to hypothetical organic chemicals that span a wide range of environmental partitioning properties, we identify combinations of properties that favor efficient transport and deposition to the Lakes. Five classes of chemicals are identified based on dominant transport and deposition pathways, and specific examples of chemicals in each class are identified and discussed. The role of vegetation in scavenging chemicals from the atmosphere is assessed, and found to have a negligible influence on transfer efficiency to the Great Lakes. Results indicate chemicals with octanol-water (Kow) and air-water (Kaw) partition coe.cients in the range of 105-107 and 10_4-10_1 combine efficient transport and deposition to the Great Lakes with potential for biaccumulation in the aquatic food web once they are deposited. A method of estimating the time scale for atmospheric transport and deposition process is suggested, and the effects of degrading reactions in the atmosphere and meteorological conditions on transport efficiency of different classes of chemicals are discussed. In total, this approach provides a method of identifying chemicals that are subject to long-range transport and deposition to specific target ecosystems as a result of their partitioning and persistence characteristics. Supported by an appropriate contaminant fate model, the approach can be applied to any target ecosystem of concern. | |
| Report number: LBNL-53245 | Year: 2004 |
| Title: Overall multi-media persistence as an indicator of potential for population-level intake of environmental contaminants | Published in: Environmental Toxicology and Chemistry, Volume 23, Pages 2465-2472. |
| Authors: MacLeod, Matthew | Type: Journal Article |
| Abstract: Although it is intuitively apparent that population-level exposure to contaminants dispersed in the environment must related to the persistence of the contaminant, there has been little effort to formally quantify this link. In this paper we investigate the relationship between overall persistence in a multimedia environment and the population-level exposure as expressed by intake fraction (iF), which is the cumulative fraction of chemical emitted to the environment that is taken up by members of the population. We first confirm that for any given chemical contaminant and emission scenario the definition of iF implies that it is directly proportional to the overall multi-media persistence, POV. We show that the proportionality constant has dimensions of time and represents the characteristic time for population intake (CTI) of the chemical from the environment. We then apply the CalTOX fate and exposure model to explore how POV and CTI combine to determine the magnitude of iF. We find that CTI has a narrow range of possible values relative to POV across multiple chemicals and emissions scenarios. We use data from the Canadian Environmental Protection Act Priority Substance List (PSL1) Assessments to show that exposure assessments based on empirical observation are consistent with interpretations from the model. The characteristic time for intake along different dominant exposure pathways is discussed. Results indicate that POV derived from screening-level assessments of persistence, bioaccumulation potential, and toxicity (PBT) is a useful indicator of the potential for population-level exposure. | |
| Report number: LBNL-54473 | Year: 2004 |
| Title: Constraining uncertainties about the sources and magnitude of polycyclic aromatic hydrocarbon (PAH)levels in ambient air: the State of Minnesota as a case study | Published in: Atmospheric Environment, Volume 38, Pages 5501-5515. |
| Authors: Lobscheid, A.B., McKone, T.E. | Type: Journal Article |
| Abstract: Emissions data are often lacking or uncertain for many airborne contaminants. Chemicals, such as polycyclic aromatic hydrocarbons (PAHs), emitted from combustion sources, fall into this category. Currently available ambient-air emission inventories of PAHs either fail to account for population-based activities (such as residential wood combustion and motor vehicle activity) and/or report 'total PAH' or particulate organic matter emissions instead of individual compounds. We measure the degree of overlap between predicted concentrations from estimated emissions with measured concentrations. Our analysis is, based on probabilistic analysis of measured outdoor air concentrations with those predicted from mass-balance models. . Based on available information, we estimate the relative magnitude of emissions from four major sources of PAHs to outdoor air- (1) on-road motor vehicles, including light-duty gasoline vehicles and diesel-powered buses and medium and heavy duty trucks; (2) residential wood combustion; and (3) power generation from external combustion boilers. We use the CalTOX regional multimedia mass-balance model to evaluate our emissions estimates in rural and urban regions of the state of Minnesota, USA. We compare model estimates of outdoor PAH airborne concentrations with those reported by the Minnesota Children's Pesticide Exposure Study (MNCPES). With these measured concentrations we probabilistically evaluate our emissions and interpret the reliability of our emissions estimates for specific PAHs. The median estimates of our predicted outdoor air concentrations agree within an order of magnitude of measured concentrations. For four representative PAHs, we were able to obtain a reasonable degree of overlap between empirical and predicted distributions of outdoor air concentrations. Our combination of models, emissions estimates, and empirical concentration data estimate exposure in a manner that is more reliable than any of these tools alone. Thereby, we increase our confidence about our plausible ranges of emissions and predicted concentrations | |
| Report number: LBNL-54846 | Year: 2004 |
| Title: Relative importance of model and parameter uncertainty in models used for prediction of persistence and long-range transport potential of chemical pollutants | Published in: 2nd Biennial Meeting of the International Environmental Modelling and Software Society, Volume 3, Pages 1229-1234. |
| Authors: Fenner, K., MacLeod, M., Stroebe, M., Beyer, A., Scheringer, M., Claudia Pahl-Wostl, Sonja Schmidt, Andrea E. Rizzoli, Anthony J. Jakeman | Type: Conference Proceedings |
| Abstract: Overall persistence (POV) and long-range transport potential (LRTP) of chemicals are two indicators used in the context of precautionary chemical assessment. Multimedia fate models are used in research and regulatory contexts to calculate numerical indicators of POV and LRTP. The resulting indicator values exhibit uncertainty due to model uncertainty concerning model design and due to type A and B parameter uncertainty in the substance parameters. In this study, we compare the relative magnitude of parameter and model uncertainty for a large set of 3175 hypothetical chemicals that evenly cover the chemical parameter space and for eight different multimedia models available for the calculation of POV and LRTP. The assessment of the relative magnitude of the two types of uncertainty is important to direct further research and to inform the user on the level of confidence he can have in the model results. It is shown that, for POV, parameter uncertainty is larger than model uncertainty in most cases (78%), and that model uncertainty becomes more important for those chemicals which partition in considerable amounts into more than one environmental compartment. For LRTP, on the other hand, model uncertainty is higher than parameter uncertainty in most cases (75%). This dominance of model uncertainty can be explained with known differences in the model features. Uncertainty of POV can thus be reduced most effectively by improving data on degradation rate constants. For LRTP, the choice of the model that is best suited for the assessment purpose in question is most essential to reduce uncertainty. | |
| Report number: LBNL-53456 | Year: 2003 |
| Title: Is there a "forest filter effect" for airborne organic pollutants? A SERRA journal forum | Published in: Stochastic Environmental Research and Risk Assessment, Volume 17, Pages 229-230. |
| Authors: Scheringer, M., McKone T.E. | Type: Journal Article |
| Abstract: Almost a year ago, George Christakos, editor of the SERRA journal asked us individually as members of the editorial advisory board to organize for the journal a forum on a topic of current interest, involving some controversy, and of interest to the journal subscribers. In May 2002 both us found ourselves at conference in Vienna, Austria and in session with a rather lively discussion on the issue of whether forests can filter pollutants out of the atmosphere. Shortly after that we recognized that this would be a good topic for a SERRA forum and agreed to jointly organize this effort. Thus, we selected as topic for our forum the role of vegetation in controlling the transport, mobility, persistence, and partitioning of organic chemicals (not metals) in regional and global environments. In October 2002 we sent an e-mail to several of our colleagues posing two questions | |
| Report number: LBNL-52193 | Year: 2003 |
| Title: Tracking Multiple Pathways of Human Exposure to Persistent Multimedia Pollutants: Regional, Continental, and Global Scale Models | Published in: Annual Review of Environment and Resources, Volume 28, Pages 11. |
| Authors: McKone, T.E., MacLeod, M.J. | Type: Journal Article |
| Abstract: Widespread observations of organic compounds in vegetation, soil, animals, and human tissue have motivated research on more accurate characterizations of chemical transport over regional, continental, and global scales. Efforts to assess human and ecosystem exposure to contaminants from multiple environmental media have been evolving over the last several decades. In this review we summarize the development and evolution of the multimedia mass-balance approach to pollutant fate and exposure evaluation and illustrate some of the calculations used in multimedia assessments. We describe the concepts that make possible the Mackay-type mass-balance compartment models. We describe ongoing efforts to use multimedia models to quantify human exposures. We use a series of case studies of varying complexity to illustrate capabilities and limitations of selected multimedia approaches. We look to the future and consider current challenges and opportunities in the field of multimedia contaminant fate and exposure modeling. | |
| Report number: LBNL-46693 | Year: 2003 |
| Title: Chemical-specific representation of air-soil exchange and soil penetration in regional multimedia models | Published in: Environmental Science and Technology, Volume 37, Pages 3123-3132. |
| Authors: McKone, T.E., Bennett, D.H. | Type: Journal Article |
| Abstract: In multimedia mass-balance models, the soil compartment is an important sink as well as a conduit for transfers to vegetation and shallow groundwater. Here a novel approach for constructing soil transport algorithms for multimedia fate models is developed and evaluated. The resulting algorithms account for diffusion in gas and liquid components; advection in gas, liquid, or solid phases; and multiple transformation processes. They also provide an explicit quantification of the characteristic soil penetration depth. We construct a compartment model using three and four soil layers to replicate with high reliability the flux and mass distribution obtained from the exact analytical solution describing the transient dispersion, advection, and transformation of chemicals in soil layers with different properties but a boundary condition at the air-soil surface. The soil compartment algorithms can be dynamically linked to other compartments (air, vegetation, ground water, surface water) in multimedia fate models. We demonstrate and evaluate the performance of the algorithms in a model with applications to benzene, benzo(a)pyrene, MTBE, TCDD, and tritium. | |
| Report number: LBNL-53457 | Year: 2003 |
| Title: Intake fraction of primary pollutants: Motor vehicle emissions in the South Coast Air Basin | Published in: Atmospheric Environment, Volume 37, Pages 3455-3468. |
| Authors: Marshall, J., Riley, W.J., McKone, T.E., Nazaroff, W.W. | Type: Journal Article |
| Abstract: The intake fraction is de.ned for a speci.c species and emission source as the ratio of attributable population intake to total emissions. Focusing on California’s South Coast Air Basin (SoCAB) as a case study, we combine ambient monitoring data with time-activity patterns to estimate the population intake of carbon monoxide and benzene emitted from motor vehicles during 1996–1999. In addition to exposures to ambient concentrations, three microenvironments are considered in which the exposure concentration of motor vehicle emissions is higher than in ambient air: in and near vehicles, inside a building that is near a freeway, and inside a residence with an attached garage. Incorporating data on motor vehicle emissions estimated by the EMFAC2000 model, we estimate that the 15 million people in the SoCAB inhale 0.003–0.009% (34–85 per million, with a best estimate of 47 per million) of primary, nonreactive compounds emitted into the basin by motor vehicles. This population intake of primary motor vehicle emissions is approximately 50% higher than the average ambient concentration times the average breathing rate, owing to higher concentrations in the three microenvironments and also to the temporal and spatial correlation among breathing rates, concentrations, and population densities. The approach demonstrated here can inform policy decisions requiring a metric of population exposure to airborne pollutants. | |
| Report number: LBNL-49570 | Year: 2002 |
| Title: Factors affecting the concentration of outdoor particles indoors: existing data and data needs | Published in: Proceedings of the Indoor Air 2002 Conference, Monterey, CA, Volume 1, Pages 176-181. |
| Authors: McKone, T.E., Thatcher, T.L., Fisk, W.J., Sextro, R.G., Sohn, M.D., Delp, W.W., Riley, W.J. | Type: Conference Proceedings |
| Abstract: Accurate characterization of particle concentrations indoors is critical to exposure assessments. It is estimated that indoor particle concentrations depend strongly on outdoor concentrations. For health scientists, knowledge of the factors that control the relationship of indoor particle concentrations to outdoor levels is particularly important. In this paper, we identify and evaluate sources of data for those factors that affect the transport to and concentration of outdoor particles indoors. To achieve this goal, we (i) identify and assemble relevant information on how particle behavior during air leakage, HVAC operation, and particle filtration effects indoor particle concentration; (ii) review and evaluate the assembled information to distinguish data that are directly relevant to specific estimates of particle transport from those that are only indirectly useful; and (iii) provide a synthesis of the currently available information on building air- leakage parameters and their effect on indoor particle matter concentrations. | |
| Report number: LBNL-50569 | Year: 2002 |
| Title: Exposure chamber measurements of mass transfer and partitioning at the plant/air interface | Published in: Environmental Science & Technology, Volume 36, Pages 3577-3585. |
| Authors: Maddalena, R.l., McKone, T.E., Kado, N.Y. | Type: Journal Article |
| Abstract: Dynamic measures of air and vegetation concentrations in an exposure chamber and a two-box mass balance model are used to quantify factors that control the rate and extent of chemical partitioning between vegetation and the atmosphere. A continuous stirred flow-through exposure chamber was used to investigate the gas-phase transfer of pollutants between air and plants. A probabilistic two-compartment mass-balance model of plant/air exchange within the exposure chamber was developed and used with measured concentrations from the chamber to simultaneously evaluate partitioning (Kpa), overall mass transfer across the plant/air interface (Upa) and loss rates in the atmosphere (Ra) and aboveground vegetation (Rp). The approach is demonstrated using mature Capsicum annuum (bell pepper) plants exposed to phenanthrene (PH), anthracene (AN), fluoranthene (FL) and pyrene (PY). Measured values of log Kpa (V[air]/V[fresh plant]) were 5.7, 5.7, 6.0 and 6.2 for PH, AN, FL and PY, respectively. Values of Upa (m d-1) under the conditions of this study ranged from 42 for PH to 119 for FL. After correcting for wall effects, the estimated reaction half-lives in air were 3, 9 and 25 hours for AN, FL and PY. Reaction half- lives in the plant compartment were 17, 6, 17 and 5 days for PH, AN, FL and PY. The combined use of exposure chamber measurements and models provides a robust tool for simultaneously measuring several different transfer factors that are important for modeling the uptake of pollutants into vegetation. | |
| Report number: LBNL-50501 | Year: 2002 |
| Title: Defining intake fraction | Published in: Environmental Science & Technology, Volume 36, Pages 207A-211A. |
| Authors: Bennett, D. H., Mckone, T.E., Evans, J.S. , Nazaroff, W.W., Margni, M.D., Jolliet, O., Smith, K.R. | Type: Journal Article |
| Abstract: Activities such as comparative risk analysis, life-cycle assessment, emissions trading and sustainable development are creating a growing demand for reliable and consistent information about the potential adverse effects of the thousands of chemicals released to the environment. This demand has fostered measurement and modeling efforts that link emissions to the resulting human exposures and subsequent health effects for a wide range of human products and activities, such manufacture and disposal of consumer goods, cooking, smoking, energy conversion, industrial production, and agriculture. For many pollutants, a preliminary estimate of the human health risk that is posed by an environmental release can be determined from the combination of three factors: (1) the quantity released; (2) the incremental intake per unit release; and (3) the risk of adverse effect per unit intake. This paper addresses the second term, the emissions-to-intake relationship. As discussed in a recent literature review, several researchers have independently developed similar approaches for relating source emissions to human intake for various pollutants and exposure pathways. Consequently, multiple terms, definitions, and units exist for what appears to be a single, yet multifaceted concept. But there are inconsistencies both in terminology and definitions among various researchers quantifying emissions-to-intake relationships. Differences in definitions leads to unnecessary complexity in comparing results from different research groups. Inconsistency in terminology when the same quantity is being calculated leads to further lack of transparency. We formed a working group and prepared this article to communicate our recommendations. for a set of terms and associated definitions that are descriptive, simple, accurate, and consistent both with common usage and usage in all relevant disciplines; are flexible to permit application over a broad range of potential uses; and reflect consensus among a large number of researchers. We propose the term intake fraction (iF) as the primary label for quantifying the emissions-to-intake relationship. Because the effort to employ intake fraction is in its early stages and is gaining momentum, now is the time to build consensus on terminology. Doing so will allow us to communicate more effectively both among ourselves and also with practitioners in related fields. | |
| Report number: LBNL-47253 | Year: 2002 |
| Title: Intake Fraction for Multimedia Pollutants: A Tool for Life Cycle Analysis and Comparative Risk Assessment | Published in: Risk Analysis, Volume 22, Pages 903-916. |
| Authors: Bennett, D.H., Margni, M.D. , McKone, T.E., Jolliet, O. | Type: Journal Article |
| Abstract: We employ the concept of Intake Fraction (iF) as an effective way to understand the source-to-dose relationship for pollutant emissions in Life Cycle Analysis (LCA) or comparative risk assessment. Intake fraction is the fraction of chemical mass emitted into the environment that eventually passes into a member of the population through inhalation, ingestion, or dermal exposure. To date, this concept has been primarily applied to pollutants whose primary route of exposure is inhalation. Here we extend the use of iF to multimedia pollutants with multiple exposure pathways. We use a level III multimedia model to calculate iF for TCDD and compare the results to one calculated from measured levels of dioxin toxic equivalents in the environment. We calculate iF for emissions to air and surface water for 244 chemicals. We correlate the primary exposure route with the magnitudes of the octanol-water partition coefficient, Kow, and of the air-water partitioning coefficient (dimensionless Henry constant), Kaw. This results in value ranges of Kow and Kaw where the chemical exposure route can be classified with limited input data requirements as primarily inhalation, primarily ingestion, or multi-pathway. For the inhalation and ingestion dominant pollutants, we also define empirical relationships based on chemical properties for quantifying dose fraction. The empirical relationships facilitate rapid evaluation of many chemicals in terms of the potential dose. By defining a theoretical upper limit for iF in a multimedia environment we find that iF calculations provide insight into the multimedia model algorithms and help identify unusual patterns of exposure and questionable exposure model results. | |
| Report number: LBNL-43722 | Year: 2001 |
| Title: Development and evaluation of state-specific landscape data sets for multimedia source-to-dose models | Published in: |
| Authors: McKone, T.E., A.B. Bodnar, E.G. Hertwich | Type: Report |
| Report number: LBNL-50571 | Year: 2001 |
| Title: BETR North America: A regionally segmented multimedia contaminant fate model for North America | Published in: Environmental Science & Pollution Research, Volume 8, Pages 156-163. |
| Authors: MacLeod, M., D.G. Woodfine, D. Mackay, T.E. McKone, D.H. Bennett, R.L. Maddalena | Type: Journal Article |
| Abstract: We present the Berkeley-Trent North American contaminant fate model (BETR North America), a regionally segmented multimedia contaminant fate model based on the fugacity concept. The model is built on a framework that links contaminant fate models of individual regions, and is generally applicable to large, spatially heterogeneous areas. The North American environment is modeled as 24 ecological regions, within each region contaminant fate is described using a 7 compartment multimedia fugacity model including a vertically segmented atmosphere, freshwater, freshwater sediment, soil, coastal water and vegetation compartments. Inter-regional transport of contaminants in the atmosphere, freshwater and coastal water is described using a database of hydrological and meteorological data compiled with Geographical Information Systems (GIS) techniques. Steady-state and dynamic solutions to the 168 mass balance equations that make up the linked model for North America are discussed, and an illustrative case study of toxaphene transport from the southern United States to the Great Lakes Basin is presented. Regionally segmented models such as BETR North America can provide a critical link between evaluative models of long-range transport potential and contaminant concentrations observed in remote regions. The continent-scale mass balance calculated by the model provides a sound basis for evaluating long-range transport potential of organic pollutants, and formulation of continent scale management and regulatory strategies for chemicals. | |
| Report number: LBNL-45690 | Year: 2001 |
| Title: Predicting Long Range Transport: A Systematic Evaluation of Two Multimedia Transport Models | Published in: Environmental Science & Technology, Volume 35, Pages 1181-1189. |
| Authors: Bennett, D.H., Scheringer, M., McKone, T.E., Hungerbühler, K. | Type: Journal Article |
| Report number: LBNL-45815 | Year: 2001 |
| Title: Characteristic time, characteristic travel distance, and population based dose in a multimedia environment: A case study | Published in: Human & Ecological Risk Assessment: Theory and Practice, Volume Chapter 11, Pages 619-643. |
| Authors: Bennett, D.H., McKone, T.E., Kastenberg, W.E., Schwalbe, C.A., Paustenbach, D. | Type: Book Section |
| Report number: LBNL-43719 | Year: 2000 |
| Title: Persistence and Transport Potential of Chemicals In A Multimedia Environment | Published in: Chapter 5 in the book, Persistence and Long-Range Transport of Organic Chemicals in the Environment:Guidelines and Criteria for Evaluation and Assessment. |
| Authors: van de Meent, D., T.E. McKone, Parkerton, T. , Matthies, M. , Scheringer, M. , Wania, F. , Purdy, R, Bennett, D.H., Klecka, G.M.,Boethling, R.S.; Franklin, J., Graham, D., Grady, Jr., L., Howard, P., Kannan, K., Larson, R., Mackay, D., Muir, D.C.G., van de Meent, D. | Type: Book Section |
| Report number: LBNL-44343 | Year: 2000 |
| Title: Relationship between Persistence and Spatial Range of Environmental Chemicals. ACS Symposium Series 773 | Published in: Persistent, Bioaccumulative, Toxic Chemicals II Assessment and New Chemicals. |
| Authors: Scheringer, M., Bennett, D.H. , McKone, T. E. , Hugerbuhler, K., Lipnick, R.L., Janson, B., Mackay, D., Petreas, M. | Type: Book Section |
| Report number: LBNL-43335 | Year: 2000 |
| Title: Influential Parameter Classification in Probabilistic Multimedia Models | Published in: Stochastic Environmental Research and Risk Assessment, Volume 15, Pages 1-17. |
| Authors: Maddalena, R.L., McKone, T. E., Hsieh, D.P.H. , Geng, S. | Type: Journal Article |
| Report number: LBNL-43721 | Year: 2000 |
| Title: CART screening level analysis of characteristic time -- a case study. ACS Symposium Series 773 | Published in: Persistent, Bioaccumulative, Toxic Chemicals II Assessment and New Chemicals. |
| Authors: Bennett, D.H., T. E. McKone, W. E. Kastenberg, Lipnick, R.L., Janson, B., Mackay, D., Petreas, M. | Type: Edited Book |
| Report number: LBNL-42897 | Year: 2000 |
| Title: Evaluating multimedia chemical persistence in a multimedia environment: A CART analysis | Published in: Environmental Toxicology and Chemistry, Volume 19, Pages 810-819. |
| Authors: Bennett, D.H., T.E. McKone, W.E. Kastenberg | Type: Journal Article |
| Report number: LBNL-45879 | Year: 2000 |
| Title: Population based dose models for multimedia chemicals with the potential for long range transport, May 2000 | Published in: |
| Authors: Bennett, D.H. | Type: Report |
| Report number: LBNL-43720 | Year: 1999 |
| Title: Evaluation of persistence and long-range transport of organic chemicals in the environment: summary of a SETAC Pellston workshop | Published in: Environmental Toxicology and Chemistry, Volume 18. |
| Authors: Klecka, G.M., D. Mackay, R.S. Boethling, T.E. McKone | Type: Journal Article |
| Report number: LBNL-43718 | Year: 1999 |
| Title: Parameter uncertainty and variability in evaluative fate and exposure models | Published in: Risk Analysis, Volume 19, Pages 1193-1204. |
| Authors: Hertwich, E.G., T.E. McKone, W. S. Pease | Type: Journal Article |
| Report number: LBNL-41929 | Year: 1998 |
| Title: Improved Landfill Simulations Based on the CalTOX Framework | Published in: |
| Authors: McKone, T.E., A.B. Bodnar | Type: Report |
| Report number: LBNL-43715 | Year: 1998 |
| Title: General formulation of characteristic travel distance for semivolatile chemicals in a multimedia environment | Published in: Environmental Science and Technology, Volume 32, Pages 4023-4030. |
| Authors: Bennett, D.H., T.E. McKone, M. Matthies, W.E. Kastenberg | Type: Journal Article |
| Report number: LBNL-41335 | Year: 1998 |
| Title: On uncertainty in remediation analysis: variance propagation for subsurface transport to exposure modeling | Published in: Reliability Engineering and System Safety, Volume 62. |
| Authors: Bennett, D.H., James, A. L., McKone, T. E., Oldenburg, C. M. | Type: Journal Article |
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