The Toxicological Effects of Intermittent Pollutant Exposures

EPA Grant Number: U915215
Title: The Toxicological Effects of Intermittent Pollutant Exposures
Investigators: Brent, Robert N.
Institution: University of Illinois at Urbana-Champaign
EPA Project Officer: Michaud, Jayne
Project Period: January 1, 1997 through January 1, 2000
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1997) RFA Text |  Recipients Lists
Research Category: Fellowship - Toxicology , Academic Fellowships , Health Effects


The objective of this research project is to investigate the toxicological effects of discontinuous or intermittent pollutant exposures on freshwater organisms and populations.


The approach that this research has taken is to decompose the factors of magnitude, duration, and frequency that will determine episodic pollution effects. The first phase of the research investigated the effects of varying magnitude and duration of single-toxic exposures. Toxicity testing methods were adapted to subject freshwater organisms to contaminant exposures at a range of concentrations and brief exposure durations (on the order of episodic event time scales). Effects of brief cadmium (Cd), zinc (Zn), and phenol exposures on Ceriodaphnia dubia, Hyalella azteca, and Pimephales promelas were assessed during a postexposure observation period of up to 7 days. The second phase of research was to investigate effects of exposure frequency. Important aspects of exposure frequency include the time period between exposures and the number of exposures per time period. This phase of the research utilized multiple C. dubia exposures to Cd and Zn that varied in both aspects of frequency. The final phase of the research incorporated information from single- and multiple-exposure testing into organism population models that may predict effects at the population level based on magnitude, duration, and frequency of exposure.

Supplemental Keywords:

fellowship, freshwater organisms, freshwater populations, toxicological effects, contaminants, pollutant exposures, toxics, toxics exposure., RFA, Scientific Discipline, ECOSYSTEMS, Ecosystem Protection/Environmental Exposure & Risk, exploratory research environmental biology, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, Ecological Effects - Environmental Exposure & Risk, Environmental Monitoring, Ecological Monitoring, Ecological Risk Assessment, Ecology and Ecosystems, Ecological Indicators, aquatic ecosystem, assessment models, toxicity studies, ecological assessment, Phenol, toxicity, Zinc, contaminant impact, toxic environmental contaminants, cadmium

Progress and Final Reports:

  • 1997
  • 1998
  • Final