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NATIONAL SCREENING SURVEY OF EDCS IN MUNICIPAL WASTEWATER TREATMENT FACILITIES
Citation:
Lazorchak, J M., M E. Smith, D L. Lattier, B E. Wiechman, A Braam, G P. Toth, R C. Brenner, AND G D. Sayles. NATIONAL SCREENING SURVEY OF EDCS IN MUNICIPAL WASTEWATER TREATMENT FACILITIES. Presented at Society of Environmental Toxicology and Chemistry, Austin, TX, November 8-13, 2003.
Impact/Purpose:
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
Description:
In 2002 and 2003 the USEPA's Office of Research and Development asked Regional EPA inspectors, state EPA inspectors and municipal plant operators to collect four gallons effluent, either as a grab or composite sample, from up to 50 wastewater treatment plants (WWTP), and ship them to Cincinnati for male and female fathead minnow exposures. The purpose of this study was to assess whether certain types of treatment plants or operations are more effective in removing endocrine disrupting chemicals (EDCs). To do this, five male and five female fathead minnows were exposed to each effluent for 24 hours, their livers were necropsied and RNA extracted and analyzed via real-time PCR for changes in vitellogenin gene expression (Vg). Each effluent assessed included two laboratory control waters (moderately hard reconstituted water with and without DMSO) and one positive control, 5 ng/L of the estrogen Ethynylestradiol (EE2). If males showed Vg levels above controls, then this would indicate the presence of an androgen or anti estrogen. Fifty-two total WWTP samples were tested from effluents in all ten USEPA Regions and representing 23 states, including Alaska and Hawaii. Six samples resulted in 100% mortality in the effluent sample being tested. Three effluents were resampled and tested. Of the 46 that were not acutely toxic, 10 (21.7%) showed elevated Vg levels in male fathead minnows and two (4.3%) showed reduced Vg levels in female fathead minnows. Two effluents that showed elevated levels in males were repeated and showed similar results.