Grantee Research Project Results
Chemical Toxicity Distributions as a Novel Approach to Assess the Sensitivities of Common In Vivo and In Vitro Assays of Environmental Estrogenicity: A Case Study with Parabens
EPA Grant Number: F07E60219Title: Chemical Toxicity Distributions as a Novel Approach to Assess the Sensitivities of Common In Vivo and In Vitro Assays of Environmental Estrogenicity: A Case Study with Parabens
Investigators: Dobbins, Laura L.
Institution: Baylor University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2007 through September 1, 2009
RFA: GRO Fellowships for Graduate Environmental Study (2007) RFA Text | Recipients Lists
Research Category: Fellowship - Aquatic Ecology and Ecosystems , Academic Fellowships , Fellowship - Ecotoxicology
Objective:
Parabens represent a class of antimicrobial agents present in thousands of food, pharmaceutical and cosmetic products. Select parabens are known to reach aquatic systems through wastewater discharges. Whereas the potential aquatic hazards of parabens have been relatively understudied, these compounds also appear to possess estrogenic properties to fish. In this study, chemical toxicity distributions (CTDs), a probabilistic ecological hazard assessment approach for evaluating groups of compounds with limited environmental exposure data, will be employed to assess the relative sensitivities of common in vivo and in vitro assays of estrogen agonist activity. A group of six parabens and their common metabolite p-hydroxybenzoic acid will be evaluated using standardized toxicity assays and biomarkers of estrogenicity using in vivo and in vitro models. CTDs will further be employed to develop a novel aquatic hazard assessment of parabens for fish.
Approach:
Acute and chronic toxicity of six parabens and p-hydroxybenzoic acid will be assessed using standard EPA protocols with Daphnia magna and Pimephales promelas. To evaluate estrogenicity of these compounds, adult male P. promelas studies will be performed with vitellogenin (VTG) induction utilized as a biomarker of estrogenicity. Paraben estrogen agonist activity will also be determined in vitro by VTG induction in hepatocyte cell cultures.
Expected Results:
It is anticipated that parabens will elicit dose-dependent responses in both in vivo and in vitro models. Subsequently, this research project will: 1. identify the relative sensitivity of the most common in vitro and in vivo assays for estrogen agonist activity to freshwater fish; 2. broaden the knowledge of aquatic hazards of parabens found in wastewater discharges; and 3. evaluate the usefulness of CTDs in risk assessment of compounds that have limited environmental exposure data.
Supplemental Keywords:
Paraben, chemical toxicity distributions, estrogen agonist, fathead minnow,Progress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.