Ecotoxicology:

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Ecotoxicology Ecological issues related to
toxic anthropogenic chemicals Endocrine
disruptors interfere with the synthesis,
secretion, transport, binding, action, or
elimination of natural hormones in the body that
are responsible for the maintenance of
homeostasis (normal cell metabolism),
reproduction, development, and/or behavior."
EPA
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Anthropogenic Chemicals Pesticides (insecticide,
herbicide, fungicide, nematicide,
avicide) Industrial chemicals (surfactancts,
heavy metals, salt, toxic organics such as
PCBs) Recreation transportation chemicals
(soot particles, gasoline) Pharmaceuticals
(chlorfibric acid, estradiol, ibuprofin,
antibiotics) Personal Care Products (perfumes)
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 synthetic organic chemicals total of ca.
70,000 different compounds. At least 150 of
these chemicals can be detected in the human body
of any person on Earth. Vitousek 1997
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The issue of scale in human ecology. Short term
individual day-to-day Long term population
dynamics
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Theo Colborn Endocrine disruptors are chemicals
that look like or interfere with the natural
hormones that control development from the moment
the sperm enters the egg, until an individual is
born Estrogens, testosterone, thyroid, and many
more. I could make a list a mile long, but
theyre all very critical, and they operate in
the body especially during development, at
concentrations as low as a tenth of a trillionth
of a gram. Its really as inconspicuous as one
second in 3,169 centuries. Thats very, very low
concentrations, and yet in the amniotic fluid in
the womb of pregnant women and in the fetuses,
chemicals are found at parts per trillion to
parts per million. Thats millions of times
higher concentrations than the natural hormones
that control development.
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Atrazine Most commonly used NA herbicide In US,
1992, 73.8 million pounds ca. 2.50/lb Syngenta
2005 (US 7.3 billion) http//ca.water.usgs.gov/pn
sp/use92/index.html
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Atrazine 0.75 lbs/acre 340 grams, 0.085
g/m2 Yahara River, spring max 10 µg/l Dodson
well water 0.1 µg/l In some organisms (some
frogs, turtles, rats, humans), atrazine induces
aromatase, which converts testosterone into
estradiol, a precursor of estrogen. What else
does atrazine do?
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PCB bioaccumulation biomagnification Lake
Ontario. PCB concentration in the lake water was
ca. 5 parts per trillion Norstrom et al. 1978
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Ambient is about 1 ppb in Wisconsin
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EXAMPLE of Endocrine Disruption and Human
Development Jacobson Jacobson Department of
Psychology, Wayne State University, Detroit, MI
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CONTROVERSY Jacobson Jacobson Department of
Psychology, Wayne State University, Detroit,
MI Cicchetti, Kaufman, Sparrow Educational
Psychology Yale University, New Haven, CT
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Acknowledgements Jacobson Jacobson Our PCB
research has been supported by grant nos.
R01-ES03256, R01-ES05843, and R01-ES07902 from
the National Institute of Environmental Health
Sciences/NIH and grant no. CR80852010 from the
U.S. Environmental Protection Agency.
Cicchetti, Kaufman, Sparrow This review was
funded by the General Electric Company.
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Why is ER controversial? Scientific
Reasons Subtle effects (sub-lethal) Lack of
experimentation Low concentrations Multiple
chemicals Unknown mechanism Insufficient
testing Lag between exposure expression Poor
baseline
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Why is ER controversial? Economic
Reasons Subtle effects (sub-lethal) Risk
Assessment Cost/Benefit High Stakes Paid-for
science (conflict of interest)
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Non-Controversial Endocrine Disruption Exposure
to high concentrations. Alligators in lake
Apopka Top carnivores, such as birds, turtles,
pumas, whales.
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Tyrone Hayes Amphibian Decline Atrazine
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Undescended testicles Our Stolen Future by
Colborn et al.
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Obesity Trends Among U.S. AdultsBRFSS, 1985
Source Mokdad A H, et al. J Am Med Assoc
199928216, 200128610.
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Obesity Trends Among U.S. AdultsBRFSS, 1991
Source Mokdad A H, et al. J Am Med Assoc
199928216, 200128610.
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Obesity Trends Among U.S. AdultsBRFSS, 2001
Source Mokdad A H, et al. J Am Med Assoc
199928216, 200128610.
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USGS National Pesticide Synthesis Project
http//ca.water.usgs.gov/pnsp/pesticide_use_maps_1
997/
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What about Hormesis? Are low levels of
contaminants beneficial? Colleen
Flaherty Prozac, Water, Daphnia 63 increase in
eggs per female.
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How can a chemical pass all tests, and still
cause adverse effects? End Points Acute
toxicity death Chronic toxicity survival,
reproduction cancer endocrine
disruption (sex ratio, morphology,
behav.) chemical communication biomagnific
ation
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Political and economic processes influence
Scientific Culture.
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Soviet agriculture and genetics were guided by
T.D. Lysenko, whose Lamarckian theories were
embraced as serving Marxist orthodoxy.
Early 1800s
1948-1965
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Political and economic processes influence
Scientific Culture. Examples of Government
Suppression or Channeling of research EPA --
Global Warming USGS -- Cariboo maps and Arctic
Drilling National Cancer Inst. Abortion
Cancer EPA Pesticides such as atrazine NSF
Sexual Behavior
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Toxicology, Industry and EPA Junk
Science Cannot Repeat Controversy No
Evidence for Humans Best Practices Editoria
l Boards Peer Review Letters to Editor
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