Mechanistic Evaluation of the Toxicity of Chemical Mixtures

EPA Grant Number: R829358
Title: Mechanistic Evaluation of the Toxicity of Chemical Mixtures
Investigators: LeBlanc, Gerald A.
Institution: North Carolina State University
EPA Project Officer: Hahn, Intaek
Project Period: September 24, 2001 through September 23, 2006
Project Amount: $465,281
RFA: Complex Chemical Mixtures (2000) RFA Text |  Recipients Lists
Research Category: Environmental Justice , Hazardous Waste/Remediation , Land and Waste Management , Safer Chemicals


Evaluating the toxicity of complex chemical mixtures is one of the major challenges facing modern toxicology. The general hypothesis to be tested in this research is that the toxicity of complex chemical mixtures can be satisfactorily estimated by understanding the mechanisms of chemical toxicity of the individual constituents and utilizing algorithms that define interactions based upon these mechanisms.


Model chemicals will be evaluated for both acute and chronic toxicity using the daphnid (Daphnia magna) as a model organism. Daphnids are ideally suited to this program since they are non-vertebrate whole organisms that are highly amenable to laboratory study. Concentration-response curves will be determined for each chemical that will provide the mechanistic data necessary to formulate algorithms that define the toxicity of binary, tertiary, etc. combinations of the chemicals. Mathematical predictions of mixtures toxicity will be compared to actual experimental results.

Expected Results:

Results from this research program will provide a solid research framework to structure evaluations of the toxicity of complex chemical mixtures. The framework will be highly adaptable for use in human health and environmental health assessments of the toxicity of mixtures. Further, the framework will be applicable for use in both retrospective and prospective assessments of the hazards of chemical mixtures.

Publications and Presentations:

Publications have been submitted on this project: View all 29 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 17 journal articles for this project

Supplemental Keywords:

modeling, hazard characterization, hazard wastes, risk., RFA, Scientific Discipline, Waste, Ecosystem Protection/Environmental Exposure & Risk, Environmental Chemistry, chemical mixtures, Fate & Transport, Hazardous Waste, Ecology and Ecosystems, Hazardous, complex mixtures, contaminated sediments, fate and transport, fate and transport , biodegradation, hazardous organic substances, environmental transport and fate, toxicity testing, chemical kinetics, hazardous chemicals, complex toxic chemical mixtures, mechanisitic research, contaminant transport models

Progress and Final Reports:

  • 2002
  • 2003 Progress Report
  • 2004 Progress Report
  • 2005
  • Final Report