Transcript Wildlife Toxicology - Arkansas State University

Wildlife Toxicology
Introduction
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Earliest type of environmental
toxicology (Silent Spring hatched
many new environmentalists -->
public most interested in wildlife
toxicology
Probably area of most true
ecotoxicology - much of other
environmental toxicology pays
"lip service" to ecological
mechanisms but wildlife
toxicology often needs good
knowledge of such mechanisms
Arose from wildlife ecology instead of
biomedical toxicology like most
environmental toxicology
Introduction (con’t)
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Much work based on putting out
"fires“
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e.g Lake DeGray eagle die-off
Newest fire in Arkansas: external
abnormalities in songbirds
associated with Delta agricultural
fields
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Craighead, Mississippi and Poinsett
counties
Normal abnormality rate = 0.5%
Delta farm field abnormality rate 7-9%
I. Basic concepts
Def. - Assessment of chemical hazards in the
environment to wildlife populations
A. Major foci
1. Assessing causes and mechanisms of
problems in the field (dousing the fire)
2. Predicting potential adverse affects
through experiments and testing.
Note: both above use laboratoy and field
testing
3. Analytical chemistry - i.d. what is
present and might be causing effect
Basic concepts (con’t)
B. Exposure vs. Effect
1. Demonstrating exposure may be hard
- tissue need to be sampled for
"right stuff”
2. "
effect of exposure is harder¯
(ex. PCBs
detectable in all of us. Effect?)
3. Cause/effect or dose/response rare in
unplanned wildlife contamination
a. mostly infer from indirect
evidence
b. graded response in wildlife with
changes in distance from source of
contamination)
II. Special Considerations in Wildlife
Toxicology
A. Definition of wildlife varies
B. Species response varies in
1. Habitat requirements
2. Activity patterns (when to apply pesticides -> bluegill vs. bass)
3. Food habits (food chain considerations)
4. Detoxification mechanisms
5. Absorption pathways
6. Life stage sensitivities
etc, etc.
C. Varied sources of stressors
1. Agrochemicals
2. Spent lead shot
3. Industrial waste
4. Acid precipitation
5. Irrigation
6. Mining
7. Logging
Summary
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Wildlife toxicology is actually the single
largest problem dealt with by environmental
toxicology
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Lots being done, but a lot less than on standard
test orgs (some changing --> switching from
Japanese quail to Bobwhite quail)