The Interaction Between Pollutants and Infectious Disease in a Model Organism

EPA Grant Number: F13F21192
Title: The Interaction Between Pollutants and Infectious Disease in a Model Organism
Investigators: Schoenle, Laura Ann
Institution: Virginia Polytechnic Institute and State University
EPA Project Officer: Lee, Sonja
Project Period: August 25, 2014 through August 25, 2016
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2013) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Terrestrial Systems Ecology


Contaminants have the potential to alter physiology, behavior, disease and fitness in organisms. This research will use red-winged blackbirds (Agelaius phoeniceus) as a model to investigate (1) the influence of mercury exposure on avian malaria parasitemia, (2) the combined effects of these environmental stressors on fitness parameters and (3) aspects of physiology and behavior that might mediate changes in fitness.


The research employs both observational and experimental techniques to elucidate the relationship between mercury exposure and an infectious disease, avian malaria. Levels of mercury and avian malaria are being assessed in red-winged blackbirds breeding in both contaminated and pristine sites to identify if there is a relationship between mercury exposure and avian malaria parasitemia. Measuring parameters of physiological health, including hematocrit and red blood cell generation rates, will determine if mercury influences a bird’s ability to tolerate the infection. To determine if mercury causes changes in physiology or the ability to resist or tolerate a malaria infection, a captive population of red-winged blackbirds will be exposed to varying levels of dietary mercury and changes in malaria parasitemia and physiological health will be evaluated.

Expected Results:

If mercury suppresses immune function, red-winged blackbirds with greater exposure to mercury are expected to exhibit higher malaria parasitemia than those with lower mercury exposure. Individuals that are exposed to both mercury and avian malaria are expected to have reduced physiological health and reproductive success than those exposed to only one or neither of these stressors.

Potential to Further Environmental/Human Health Protection

In the struggle to manage the existing levels of environmental contamination and as growing human populations create more waste, it is imperative to understand the effects of contamination on ecosystems. Contaminants have the potential to enhance the effects of disease on wildlife population; thus, to accurately assess the effects of contaminants, it must be determined whether the effects of exposure to both a contaminant and a disease are synergistic or additive. This knowledge is essential to inform policy decisions regarding environmental contamination and cleanup.

Supplemental Keywords:

malaria, mercury, red-winged blackbird

Progress and Final Reports:

  • 2015
  • Final