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Exposure databases and exposure surveillance: Promise and practice

AIHA Journal 2002年第2期63卷 205-212页

作者： LaMontagne, Anthony D Herrick, Robert F Van Dyke, Michael V Martyny, John W Ruttenber, A James [a] Center for Community-Based Research Dana-Farber Cancer Institute 44 Binney St. Boston MA 02115 E-mail: anthony.lamontagne@med.monash.edu.au [b] Environmental Science & Engineering Program Department of Environmental Health Harvard School of Public Health 665 Huntington Ave. Boston MA 02115 [c] Tri-County Health Department 4301 East 72nd Ave. Commerce City CO 80222 [d] Department of Preventive Medicine & Biometrics University of Colorado Health Sciences Center Campus Box C-245 4200 East Ninth Ave. Denver CO 80262 [e] Current address: Department of Epidemiology & Preventive Medicine Monash Medical School at Alfred Hospital Commercial Road Prahan VIC 3181 Australia

Based on recent developments in occupational health and a review of industry practices, it is argued that integrated exposure database and surveillance systems hold considerable promise for improving workplace health and safety. A foundation from which to build practical and effective exposure surveillance systems is proposed based on the integration of recent developments in electronic exposure databases, the codification of exposure assessment practice, and the theory and practice of public health surveillance. Exposure surveillance practices in general industry are reviewed based on the published literature as well as an Internet survey of three prominent industrial hygiene e-mail lists. Although the benefits of exposure surveillance are many, relatively few organizations use electronic exposure databases, and even fewer have active exposure surveillance systems. Implementation of exposure databases and surveillance systems can likely be improved by the development of systems that are more responsive to workplace or organizational-level needs. Strategies for improving the implementation of exposure database and surveillance systems are outlined.

关键词： exposure database exposure surveillance hazard surveillance industrial hygiene database intervention effectiveness research public health surveillance

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The El Niño-Southern oscillation and long-range forecasting of flows in the ganges

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International Journal of Climatology 2001年第1期21卷 77-87页

作者： Whitaker, Douglas W. Wasimi, Saleh A. Islam, Shafiqul Cincinnati Earth Systems Science Program Department of Civil and Environmental Engineering University of Cincinnati Cincinnati OH United States Faculty of Informatics and Communication Central Queensland University Rockhampton Australia

Several recent studies have shown that the El Niño-Southern Oscillation (ENSO) index has a significant influence on various climatic and hydrologic signals across the globe. This study attempts to identify the nature and strength of possible teleconnections between the Ganges River flow and ENSO, and to develop a model which can capture, at least in part, the natural variability of flow, and provide a large forecasting lead-time. The motivation came from the fact that, in the past, hydrologic forecasts of the basin through rainfall-runoff modelling could provide a lead-time on the order of the basin response time, which is several days or so. Such a short forecasting lead-time is not adequate to hedge against extreme events (flood or drought) in large river basins. This is, perhaps, the first attempt to relate flows in the Ganges with ENSO. Our analysis suggests that a significant relationship exists between the natural variability of the Ganges annual flow and ENSO index. Through further investigation, we show that the rate of change of ENSO index is also statistically related to the Ganges flow. A statistical model that combines all these indicators to forecast annual flow in the Ganges is proposed. This model uses current flow data, predicted ENSO data and its gradient to forecast flow in the Ganges with a forecasting lead-time of 1 year. The model also provides a quantitative measure of forecasting uncertainty. A key advantage of this model is that it does not require rainfall and stream flow information from upstream areas and countries. We have used 45 years of data for model development and calibration, and 15 years of data for validation. It is encouraging to note that all four of the validation forecasts during the El Niño and La Niña events are within the 95% confidence intervals. These results demonstrate the strength of the proposed approach Fand suggest further exploration of this long-range forecasting methodology for other major rivers in the world. C

关键词： ENSO Ganges Southern Asia Statistical modelling Stream flow forecasting

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Urban cover mapping using digital, high-spatial resolution aerial imagery

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Urban Ecosystems 2001年第4期5卷 243-256页

作者： Myeong, Soojeong Nowak, David J. Hopkins, Paul F. Brock, Robert H. Program in Environmental and Resource Engineering SUNY College of Environmental Science and Forestry Syracuse USA USDA Forest Service Northeastern Research Station SUNY College of Environmental Science and Forestry Syracuse USA

High-spatial resolution digital color-infrared aerial imagery of Syracuse, NY was analyzed to test methods for developing land cover classifications for an urban area. Five cover types were mapped: tree/shrub, grass/herbaceous, bare soil, water and impervious surface. Challenges in high-spatial resolution imagery such as shadow effect and similarity in spectral response between classes were found. Classification confusion among objects with similar spectral responses occurred between water and dark impervious surfaces, concrete and bare-soil, and grass/herbaceous and trees/shrub. Methods of incorporating texture, band ratios, masking of water objects, sieve functions, and majority filters were evaluated for their potential to improve the classification accuracy. After combining these various techniques, overall cover accuracy for the study area was 81.75%. Highest accuracies occurred for water (100%), tree/shrub (86.2%) and impervious surfaces (82.6%); lowest accuracy were for grass/herbaceous (69.3%) and bare soil (40.0%). Methods of improving cover map accuracy are discussed.

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BMP filters: Upflow vs. downflow

BMP filters: Upflow vs. downflow

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engineering Foundation Conference on Linking Stormwater BMP Design and Performance to Receiving Water Impact Mitigation

作者： Clark, Shirley Pitt, Robert Balakrishnan, Anitha Postgraduate Research Program Oak Ridge Institute for Science and Education National Risk Management Research Laboratory Edison NJ United States Department of Civil and Environmental Engineering University of Alabama at Birmingham Birmingham AL United States

ISBN: (纸本)9780784406021

Stormwater filters are typically operated in a downflow mode. This research had two objectives: (1) to determine the increased life of a filter operated in an upflow mode, and (2) to determine if the operation of a downflow, mixed-media filter could be modeled using the power equation proposed by Urbonas. The results showed that upflow operation could provide longer filter run times. Using laboratory-scale columns, the use of a power equation to model downflow filtration was also demonstrated. Model confirmation using pilot-scale columns is currently underway. © 2004 ASCE.

关键词： Bandpass filters

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Measurements of infiltration rates in compacted urban soils

Measurements of infiltration rates in compacted urban soils

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engineering Foundation Conference on Linking Stormwater BMP Design and Performance to Receiving Water Impact Mitigation

作者： Pitt, Robert Chen, Shen-En Ong, Choo Keong Clark, Shirley Department of Civil and Environmental Engineering University of Alabama at Birmingham Birmingham AL 35226 United States Postgraduate Research Program Oak Ridge Institute for Science and Education National Risk Management Research Laboratory Edison NJ 08837 United States

ISBN: (纸本)9780784406021

Previous research has identified significant reductions in infiltration rates in disturbed urban soils. More than 150 prior tests were conducted in predominately sandy and clayey urban soils in the Birmingham and Mobile, Alabama, areas. Infiltration in clayey soils was found to be affected by an interaction of soil moisture and compaction, while infiltration in sandy soils was affected by soil compaction alone. The tests reported here were conducted under more controlled laboratory conditions and represent a wider range of soil textures and specific soil density values. © 2004 ASCE.

关键词： Infiltration

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Helium tracer tests for assessing contaminant vapor recovery and air distribution during in situ air sparging

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Bioremediation Journal 2001年第4期5卷 321-336页

作者： Johnson, Richard L. Johnson, Paul C. Johnson, Tim L. Leeson, Andrea Department of Environmental Science and Engineering Oregon Health and Science University OGI School of Science and Engineering Portland OR United States Department of Civil and Environmental Engineering Arizona State University Tempe AZ United States Battelle Memorial Institute Columbus OH United States SERDP ESTCP Program Office Arlington VA United States

Helium tracer tests are used as an alternative to soil-gas pressure measurements to assess the effectiveness of soil vapor extraction (SVE) systems for capturing contaminant vapors liberated by in situ air sparging (IAS). The tracer approach is simple to conduct and provides more direct and reliable measures than the soil-gas pressure approach. The tracer test described here can be used to both determine SVE system capture efficiency and to evaluate air distribution during IAS pilot tests. The tests can also be conducted on operating, full-scale systems to confirm system performance. In addition, the tests can be easily repeated, which allows system parameters to be modified and the impact of those modifications to be quickly assessed. Whether used alone or in conjunction with other diagnostic tools, helium tracer tests provide an important measure of IAS system performance. © 2001 by Battelle Memorial Institute.

关键词： Air

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Diagnosis of in situ air sparging performance using transient groundwater pressure changes during startup and shutdown

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Bioremediation Journal 2001年第4期5卷 299-320页

作者： Johnson, Richard L. Johnson, Paul C. Johnson, Tim L. Thomson, Neil R. Leeson, Andrea Department of Environmental Science and Engineering Oregon Health and Science University OGI School of Science and Engineering Portland OR United States Department of Civil and Environmental Engineering Arizona State University Tempe AZ United States Department of Civil Engineering University of Waterloo Waterloo ON Canada Battelle Memorial Institute Columbus OH United States SERDP ESTCP Program Office Arlington VA United States

Groundwater pressure measurements during startup and shutdown of in situ air sparging (IAS) systems are used to diagnose air flow behavior below the water table. The magnitude of the pressure response provides insight into the permeability of the zone into which the air is flowing. The duration of elevated pressures during startup and reduced pressures during shutdown indicate the extent to which air is being trapped below the water table by lower-permeability layers. The pressure measurements can be easily and quickly repeated and as a result are useful for both pilot tests and for optimizing operating conditions of existing IAS systems. Whether used alone or in conjunction with other diagnostic tools, pressure measurements are an important tool for assessing IAS performance. © 2001 by Battelle Memorial Institute.

关键词： Pressure measurement

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Diagnostic tools for integrated in situ air sparging pilot tests

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Bioremediation Journal 2001年第4期5卷 283-298页

作者： Johnson, Richard L. Johnson, Paul C. Amerson, Illa L. Johnson, Tim L. Bruce, Cristin L. Leeson, Andrea Vogel, Catherine M. Oregon Health and Science University OGI School of Science and Engineering Portland OR United States Department of Civil and Environmental Engineering Arizona State University Tempe AZ United States SERDP ESTCP Program Office Arlington VA United States

In situ air sparging (IAS) pilot test procedures have been developed that provide rapid, on-site information about IAS performance. The standard pilot test consists of six activities conducted to look for indicators of infeasibility and to characterize the air distribution to the extent necessary to make design decisions about IAS well placement. In addition, safety hazards that need to be addressed prior to full-scale design are identified. Two additional pilot test activities are described in those cases where air distribution must be more precisely defined. The test activities include both chemical tests (tracking contaminant concentrations, dissolved oxygen and tracers) and physical tests (air flow rate and injection pressure, groundwater pressure response). Pilot test data from Eielson Air Force Base, Alaska illustrates implementation of the pilot test and interpretation of the data. © 2001 by Battelle Memorial Institute.

关键词： Groundwater

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Advances in in situ air sparging/biosparging

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Bioremediation Journal 2001年第4期5卷 251-266页

作者： Johnson, Paul C. Johnson, Richard L. Bruce, Cristin L. Leeson, Andrea Department of Civil and Environmental Engineering Arizona State University Tempe AZ United States Oregon Health and Science University OGI School of Science and Engineering Beaverton OR United States Battelle Memorial Institute Columbus OH United States SERDP ESTCP Program Office Arlington VA United States

In situ air sparging (IAS) is a technology commonly used for treatment of submerged source zones and dissolved groundwater plumes. The acceptance of IAS by regulatory agencies, environmental consultants, and industry is remarkable considering the degree of skepticism initially surrounding the technology in the early 1990s. Much has been learned and reported in the literature since that time, but it appears that practice has changed little. In particular, conventional pilot testing, design, and operation practices reflect a lack of appreciation of the complex phenomena governing IAS performance and the unforgiving nature of this technology. Many systems are poorly monitored and likely to be inefficient or ineffective. Key lessons-learned since the early 1990s are reviewed and their implications for practice are discussed here. Of particular importance are issues related to: (a) the understanding of air flow distributions and the effects of geology and injection flowrate, (b) the need to characterize air flow distributions at the pilot- and field-scale, (c) how changes in operating conditions (e.g., pulsing) can affect performance improvements and reduce equipment costs, and (d) how conventional monitoring approaches are incapable of assessing if systems are performing as designed. © 2001 by Battelle Memorial Institute.

关键词： Air

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Water policy in the United States: A perspective

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Water Policy 2001年第3期3.0卷 175-192页

作者： Deason, Jonathan P Schad, Theodore M Sherk, George William Environmental and Energy Management Program School of Engineering and Applied Science George Washington University Washington DC 20052 United States Department of Water Resources Arlington VA 22207 4540 25th Road North United States Center for Risk Science and Public Health School of Public Health and Health Services George Washington University Washington DC 20037 2300 K Street N.W. United States Alexandria VA 22314 801 N. Pitt Street United States

Lessons learned from the evolution of US water policy over two centuries of rapid population growth, economic expansion and urban development may shed light on promising approaches to issues in other areas of the world. An explanation of the major philosophical and legal underpinnings of water quantity and water quality policies that have evolved in the US federal-state system is presented. Other areas of the world may benefit from mistakes made during the evolution of US water policy in the areas of institutional reform, improved processes for conflict resolution, and increased use of modern planning and decision making procedures. © 2001 Elsevier science Ltd. All rights reserved.

关键词： population growth Unite resin Conflict Resolution water quantity Water policy Perspective

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