You are here:
PROPOSED WATER QUALITY SURVEILLANCE NETWORK USING PHYSICAL, CHEMICAL AND BIOLOGICAL EARLY WARNING SYSTEMS (CBEWS)
Lazorchak, J M., H. J. Allen, R Haught, D L. Lattier, AND J A. Goodrich. PROPOSED WATER QUALITY SURVEILLANCE NETWORK USING PHYSICAL, CHEMICAL AND BIOLOGICAL EARLY WARNING SYSTEMS (CBEWS). Presented at Society of Environmental Toxicology and Chemistry, Austin, TX, November 8-13, 2003.
The indeterminate condition of exposure indicator research stands to change markedly with the ability to connect molecular biological technologies with cellular or tissue effects and outcomes. Three focal areas of ecological research aim to develop a sequence of approaches where "the earliest recognizable signatures of exposure" (i.e., unique patterns of up- and down-regulated genes and proteins) are identified for numerous stressors, demonstrable in case studies and incorporated into Agency, State and Regional studies supported by EMAP and other programs.
Area 1, Computational Toxicology Research: Exposure assessment has historically been based on use of chemical analysis data to generate exposure models. While biological activity of chemicals has been recognized to be important for exposure risk assessments, measurement of such activity has been limited to whole organism toxicity tests. Use of molecular approaches will:
improve extrapolation between components of source-to-outcome continuum (source , exposure , dose , effect , outcome)
Using a systems modeling approach, gene and protein expression data, in small fish models (fathead minnow and zebrafish), will be integrated with metabolomic and histopathological data. This will assist in prediction of environmental transformation and chemical effects based on structural characteristics, and enhance quantitative risk assessments, including areas of uncertainty such as a basis for extrapolation of effects of endocrine disrupting chemicals, interspecies extrapolation, complex chemical mixtures and dose-response assessment.
Area 2, Ecological Research-Environmental Diagnostics: Development of molecular diagnostic indicators contributes to several of the GPRA Diagnostic Research Goals. Methods will employ DNA microarray technology and expression proteomics, focusing on species of relevance to aquatic ecosystem risk assessment. Significantly, these diagnostic indicators will open the door to understanding subcellular interactions resulting from exposure to complex chemical mixtures.
define relationship between genetic disposition of populations and degree/specificity of stressor-specific gene transcriptional response in aquatic organisms (fish and invertebrates)
identify of chemical mixture induced transcriptional "patterns" using microarrays and hyperspectral scanning - via collaboration with DOE Sandia National Labs
apply molecular indicators to watershed level stressor study, including pilot studies with targeted pesticides and toxins indicators
develop molecular indicators of exposure for invertebrates (Daphnia, Lumbriculus, Chironomus)
Area 3, Exposure Research in Endocrine Disruptors:
Subobjective 1: Develop exposure methods, measurement protocols, and models for assessment of risk management practices of endocrine disrupting compounds. As risk management approaches are identified and developed, there will be a need to identify, adapt and develop bioassay screening tools and other analytical methods to assess their efficacy. Measurements research will be performed to define management needs. This effort will entail cross-lab participation from NRMRL, NERL and NHEERL.
Subobjective 2: Determine extent of environmental and human exposures to EDCs, characterize sources and factors influencing these exposures, develop and evaluate risk management strategies to reduce exposures. In order to develop effective risk management strategies, it is important to understand the extent of exposures to endocrine disrupting compounds and factors influencing source-to-exposure-to-dose relationships.
apply molecular indicators of exposure to estrogenic compounds in selected wastewater treatment plants located in ten USEPA Regions
identify differential gene expression following exposure of fathead minnows to environmental androgens and androgen-like compounds
apply molecular indicators of exposu
The Homeland Protection Act of 2002 specifically calls for the investigation and use of Early Warning Systems (EWS) for water security reasons. The EWS is a screening tool for detecting changes in source water and distribution system water quality. A suite of time-relevant biological and physical/chemical water quality monitors applied in an EWS can provide timely information to aid decision-makers in the management and protection of the nation's water resources and measure the success of water quality control programs implemented under the Clean Water Act. A suite of monitors is necessary because no single organism will be sensitive to all contaminants at relevant concentrations. Current CBEWS in Europe use fish, bivalves, arthropods, and bacteria and are capable of detecting contaminants at relatively short time periods (hours). Strategic placement of water quality monitors in locations of high vulnerability in both source water and distribution systems may detect the presence of unsuspected chemicals or toxic interactions occurring as a result of spills, legal or illegal discharges, or intentional introductions. This work couples the "canary in the coal mine" approach with the latest in behavioral, physiological, and physical/chemical monitoring techniques and current computing and communications equipment, to provide time-relevant data over a range of spatial scales (e.g., watersheds or regions). We propose to go beyond the Euopean approach by investigating the use of a combination of advanced technologies that are time-relevant whole organism and molecular biosensing methods. Ultimately, we envision setting up a continuous, time-relevant national water quality surveillance network in all major rivers in the U.S. that are used for water supplies and their distribution systems. Complimenting whole organism systems will be molecular measures on fish and invertebrates using microarray technologies and near-real-time PCR methods for measuring gene expression.