Fish and Wildlife Toxicology 2006
Bonus Questions and Team Point Totals
Date/Team Question Respondent Points
1-10 1 Bti is a soil bacteria that is effective to control a variety of insects,
particularly Lepidoptera and mosquito larvae. Like pyrethrum, it is best described as an
insecticide that is a biological control agent. Cristiane 1
2 As a contaminant biologist you are interested in studying the indirect
effects of pesticides on warm-blooded animals. What class of insecticides would you
choose and why? SPs – low toxicity to warm-blooded animals.
3 OPs and CBs share what mode of action? Briefly describe. AChE
inhibitors – inhibiting AChE resulting in an accumulation of ACh within the nerve
synapse, tetany, and respiratory failure. Cindy 1
4 What is the relationship between pyrethrum. SPs and te re-occurrence of
the use of DDT in some African countries? Resistance to SPs in mosquitoes has led to
a re-use of DDT in fighting malaria. Matt 1
5 Distinguish between dose and dosage. Why is this distinction so
important in toxicology? Dose = amount given (mg); dosage = amount per unit body
weight (mg/kg BW). Animals of different sizes can get the same dose but very
different dosages. Adam 1
1-12 1 Where would you look to find out how to correctly apply a pesticide? The
label. Rachel 1
2 This contaminant is one of the earliest to affect wildlife, resulting in a 2-
3% decline annually in waterfowl populations. And is currently banned from use in
wetland habitats. What is it? Lead shot. Emily 1
3 What do thallium, arsenic, mercury, and copper sulfate have in common?
Two answers – give one? Naturally occurring substances used as pesticides before
WWII. Kati 1
4 Several characteristics made DDT an attractive insecticide, and in some
countries these same characteristics make it attractive today. Give two. High
persistence; toxicity to invertebrates high, mammals low; cheap.
5 How would you differentiate between formulated product and tank mix or
end product? FP=AI+other ingredients (incl adjuvants)+carrier and is what is sold
retail; TM = FP+adjuvants+carrier and is what is applied.
1-17 1 What was the primary message of Silent Spring relative to pesticide use?
Pesticide use was being abused/over used without adequate controls.
2 If one says that pesticides or other contaminants are safe because they
were not detected in the environmental matrices of concern, why would you question
this? What were the detection limits? Truda 1
3 What did Derek Ratcliffe measure and what did he compare that led to the
connection between DDT and reproductive failure in several orders of birds? Eggshell
weights from raptors before and after WWII. Emily 1
4 Why wasn’t DDE-induced eggshell thining discovered earlier? DDT had
been used for years to control insects in poultry operations. Galliforms not susceptible
to DDE-induced eggshell thinning. Heidi 1
5 What natural history characteristics and contaminant issue do American
robins and American woodcock share? Eat earthworms and suffered effects of OC’s;
DDT and heptachlor, respectively. Will 1
ALL Michael Crichton suggests that millions of people have died because of
the ban of DDT. Why does he say this? Ban of DDT resulted in the use of SPs, more
expensive and for which mosquitoes have developed resistance resulting the deaths
of many Africans, particularly children. ALL TEAMS 1
1-24 1 What factors were involved in EPA’s decision to adopt its New Paradigm
for Ecological Risk Assessment? Cost of field studies without application of results
and failure to come to a regulatory decision. Vija 1
2 What recent technology will continue to be instrumental in adopting a
landscape approach tp pesticide regulation? GIS Adam 0
3 With the Headwaters vs Talent Irrigation District ruling by the 9th Circuit
Court of Appeals, what conflict emerged with existing federal regulatory legislation?
Should pesticide inputs to surface waters be controlled by FIFRA or the CWA?
4 What will be a common mistake on the first exam with respect to NEPA?
This legislation is the most important for the environmental movement in the US,
but not fish and wildlife toxicology (FIFRA). Matt 1
5 What is the connection between pesticides and the MBTA? Birds killed
by pesticides can be considered an illegal take under the MBTA.
1-31 1 What would be a relatively easy way to imporive the Quotient given that
surrogates (lab species) would be used to determine the LOC? Actual residues in
pertinent environmental matrices. Glenda 1
2 You calculate the Quotient and get a value of 0.25. What does this mean?
Low hazard. Emily 1
3 For a non-listed bird species, what would be the LOC? 1/5th the LD or
LC50. Emily 1
4 In obtaining the EEC, where would you look if the registrant did not
provide one? Kenaga Nomogram Heidi 1
5 What is the Quotient? EEC/LOC Adam 1
ALL Why did it take so long for Congress to repeal the Delaney Clause and
require EPA to set tolerance limits for carcinogens in processed and raw food? Members
of Congress did not want to appear soft on carcinogens. TEAMS 1,2 and 3 1
ALL Viktor Yuschenko’s successful bird to become President of the Ukraine
was marred in political intrigue in large part because of this environmental contaminant.
What is the contaminant and in what context have we discussed it in class? Dioxin,
contaminant in Agent Orange. Team 1 (2), 3(1) and 4(2)
2-7 1 What is the most fundamental concept in toxicology? Dose response.
2 How would you characterize respondents on the left side of the normal
distribution? Hypersensitive. Truda 1
3 How would you characterize respondents on the right side of the normal
distribution? Hyposensitive. Tim 1
4 Based on the data given below, what are the units associated with
pesticide exposure? mg/kg BW Demetrius 1
Data for plotting dose response curve
Dosage # of respondents % mortality
1 0/10 0
2 1/10 10
4 4/10 40
8 7/10 70
16 9/10 90
32 10/10 100
5 What was the toxicity test? Acute, LD50. Rob 1
1 How are the dosages arranged? Geometrically Vija 1
2 Two chemicals have the same LC50, but one has a much steeper dose
response curve. For which chemical do you not want to make a error in assessing
hazard? Steep curve. Jay 1
3 Which chemical has the larger margin of safety? Steep curve.
4 Given two dose response curves, one steep, and one shallow widely
separated separated along a concentration gradient, what are the units on the X axis?
ppm. Demetrius 1
5 How would you compare the relative hazards associated with these two
chemicals? Larger margin of safety with shallow curve which is way to the right of
the steep curve; do not want to make a mistake in assessing hazard associated with
the steep curve Will 1
2-9 ALL Given the data below for juvenile rainbow trout ( a non-listed species) in
an environment where the maximum exposure is known to be 1 ppm.
Data for plotting dose response curve
Conc # of respondents
What are the units and the progression? ppm, 1.5x
What is the LC50? 24-26 ppm
What is the EEC? 1 ppm
What is the LOC? 1/10th the LC50 = 2.4-2.6
What is the Quotient? 0.38
What is the conclusion in terms of hazard? Low
2-21 1 Behavior can influence the exposure of fish and wildlife to contaminants.
Give one example, be specific. Fenthion, wet meadow habitat in Wyoming, mosquito
control, Wilson’s phalaropes susceptible because of foraging behavior.
2 What is the connection between behaviors that aggregate animals and
contaminant exposure? Aggregations increase potential for exposure.
3 How can the formulation of a pesticide later the exposure of animals to
contaminants? May increase absorption or result in exposure to “other” ingredients.
4 What is the dilemma associated with insecticide use and the exposure of
many birds and mammals to these chemicals? Abundance of pests coincides with peak
reproductive season of the non-targets. Matt 1
5 Environmental conditions can also alter the exposure of animals to
contaminants. Give one example. Increase in temperature resulting in decrease in
activity of birds in desert environments. Emily 1
1 In general terms, how would you rank the toxicity of Ops to amphibians,
reptiles, birds and mammals? Reptiles=birds>mammals>amphibians.
2 Why are birds believed to be more sensitive to Ops than mammals? Birds
lack A-esterases. Emily 1
3 How would you differentiate synergism and potentiation? Synergism is a
non-additive increase in toxicity among two chemicals with the same mode of action;
potentiation, an increase in toxicity between two chemicals with different modes of
action. Tim 1
4 Antagonism between chemicals is commonly used in pharmacology in
dealing with poisonings in humans and animals. What term applies to this? Antidote
5 Why are additive toxicities not considered chemical interactions? By
definition, chemical interactions must be non-additive. Adam 1
1 Give one factor governing differences in interspecies sensitivity.
absorption. Cristiane 1
2 Give another. translocation. Truda 1
3 Give another. biotransformation Rex 1
4 What is the connection between lead poisoning in waterfowl and the birds
diet? Harder the diet (e.g., corn), the greater the amount of erosion of lead shot in
the gizzard and resulting toxicity. Heidi 1
5 Based on Mike Hooper’s presentation, what factor(s) were most important
in governing the exposure of hawks to monocrotophos and ultimately their deaths?
Migration, habitat use, diet, toxicity of the OP. Rob 1
2-28 ALL Examining the brain AChE data for laughing gull adults and chicks that
died following exposure to parathion (as reported by White et al.), answer the following
(a) Are these chicks altricial or precocial? Precocial, because control
levels are the same between chicks and adults. 1,2,3 and 4 1
(b) How do you explain the dead chicks with brain AChE levels equal to
that in live chicks? These chicks died from loss of their parents. 3 and 4 1
ALL Examining the data for mallard ducklings exposed to lethal levels of
monocroptophos, how do you explain the fact that brain AChE inhibition in the dead
ducklings is lower than the diagnostic threshold for mortality induced by ChE inhibitors?
Dosage was so high that the parasympathetic nervous system shut down before
brain inhibition could reach the diagnostic threshold. 1 and 2
Team Names Total Bonus Points
1 Precocial Chicks 17
2 Aliquots 14
3 Dead Chick Society 16
4 Enolators 16
5 Agent Orange 12