Impact/Purpose:

The overall aim of this study is to test the hypothesis that mixtures of estrogenic chemicals will have adverse effects on the reproductive health of exposed aquatic organisms that cannot solely be accounted for by the summation of individual effects. The proposed study will allow us to survey relevant exposure concentrations for mixtures of endocrine disrupting chemicals that include alkylphenol polyethoxylates, estrogens, and pharmaceuticals in municipal waste water treatment plant effluents; correlate reproductive effects in exposed organisms to biochemical pathway endpoints; and validate the applicability of these biochemical endpoints as rapid assessment tools in field exposures at the surveyed treatment plants.

Description:

Phase 1 of the project, the analysis of two wastewater effluents, and Phase 2A, controlled laboratory exposure experiments have been completed for all compounds and mixtures (estrogens, alkylphenols, pharmaceuticals).  The linkage of observed behavioral, anatomical and physiological endpoints to upstream neuroendocrine endpoints indicative of exposure has advanced considerably (Phase 2B).  We have also conducted two field validation studies in Phase 3 of the project. Most compounds were found in higher concentrations in the Boulder treated effluent.  Both effluents exhibited temporal variability creating continuously changing complex mixtures. 

We have completed exposure experiments with diatoms, daphnia and fathead minnows in the St. Cloud State University Aquatic Toxicology Laboratory for all proposed classes of endocrine disrupting compounds and their mixtures. We have been working to test the hypotheses that brain adrenergic, dopaminergic and serotonergic systems are sensitive biomarkers of estrogen exposure that predict fitness outcomes.  Our investigations include immunohistochemical detection of monoamine-synthesizing enzymes and detection of monoamines by HPLC. We have completed analysis of monoamine turnover in 100% of brains from single estrogen and estrogen mixture exposures. We have identified estrogen-specific responses in the brains of fathead minnows that corroborate preliminary findings from behavioral and immunohistochemical analyses.  Preliminary results demonstrate that brain monoamines are sensitive to low dosages of exogenous estrogens.  Monoaminergic responses appear especially sensitive to low-dose exposure to estrone. We have completed preparation of 100% of control, estrogen, and estrogen-mixture brains for immunohistochemical characterization of estrogen impacts on tyrosine hydroxylase immunoreactivity (TH-ir).  Preliminary results suggest TH-ir is a sensitive early endpoint and that effects of estrone on TH-ir are distinct from estradiol, ethynylestradiol, or nonylphenol.  Estrone-exposed fathead minnows have dramatically enhanced extra-hypothalamic fiber tract TH-ir.  Further immunohistochemical investigations have established that this extrahypothalamic immunoreactivity is adrenergic and not dopaminergic.

URLs/Downloads:

Final Progress Report

2007 Progress Report

2008 Progress Report

2006 Progress Report

Record Details:

Record Type:PROJECT( ABSTRACT )

Start Date:11/01/2005

Completion Date:10/31/2008

Record ID: 146406

Show Additional Record Data

Related Organizations:

Role :OWNER

Organization Name :SAINT CLOUD STATE UNIVERSITY

Mailing Address :720 4th Ave S As209

Citation :St Cloud

State :MN

Zip Code :56301



Role :OWNER

Organization Name :UNIVERSITY OF COLORADO - BOULDER

Mailing Address :Campus Box 17

Citation :Boulder

State :CO

Zip Code :80309



Role :OWNER

Organization Name :U.S. GEOLOGICAL SURVEY

Citation :Washington

State :DC

Project Information:

Approach :

The objective of this proposal is to develop applicable rapid assessment tools to determine biologically relevant effects of exposure to mixtures of endocrine disrupting chemicals. A three-phase approach is employed to complete this objective: (1) we will survey concentrations of relevant chemicals in the effluents of two wastewater treatment plant effluents; (2) in a series of experiments, we will expose aquatic organisms to relevant concentrations of these mixtures, determine their effect on multiple reproductive endpoints, and correlate these effects with alterations in biochemical pathways; finally (3) we will test the applicability of the biochemical pathway endpoints in two field exposure studies using wastewater effluents from the same treatment plants that were sampled in phase 1.

Cost :$599,640.00

Research Component :Economics and Decision Sciences

Approach :

The objective of this proposal is to develop applicable rapid assessment tools to determine biologically relevant effects of exposure to mixtures of endocrine disrupting chemicals. A three-phase approach is employed to complete this objective: (1) we will survey concentrations of relevant chemicals in the effluents of two wastewater treatment plant effluents; (2) in a series of experiments, we will expose aquatic organisms to relevant concentrations of these mixtures, determine their effect on multiple reproductive endpoints, and correlate these effects with alterations in biochemical pathways; finally (3) we will test the applicability of the biochemical pathway endpoints in two field exposure studies using wastewater effluents from the same treatment plants that were sampled in phase 1.

Cost :$599,640.00

Research Component :Endocrine Disruptors

Project IDs:

ID Code :R832741

Project type :EPA Grant