The Ecological Effects of Endocrine Disruption Dr' David Walker University of Arizona

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The Ecological Effects of Endocrine
DisruptionDr. David WalkerUniversity of Arizona
David Walker1, Nick Paretti2, Gail Cordy2,
Timothy S. Gross3, Edward T. Furlong4, Dana W.
Kolpin5, and Dennis McIntosh6 1 University of
Arizona, Environmental Research Laboratory, 2601
E. Airport Dr., Tucson, AZ 85706
dwalker_at_ag.arizona.edu 2 USGS., WRD, 520 N. Park
Ave, Suite 221, Tucson, AZ 85719
nvp_at_email.arizona.edu 3 USGS-Florida Caribbean
Science Center, 7920 NW 71st St., Gainesville
Florida, 32653 tim_s_gross_at_usgs.gov 4 USGS,
National Water Quality Laboratory, Denver Federal
Center, P.O. Box 25046, MS 407, Lakewood, CO
80225-0046 efurlong_at_usgs.gov 5 USGS, WRD, P.O.
Box 1230, Iowa City, IA 52240 dwkolpin_at_usgs.gov 6
Delaware State University, 1200 N. DuPont Highway
Dover, DE 19901 dmcintosh_at_desu.edu
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For Our Purposes

• An endocrine disruptor is a synthetic
  (anthropogenic) chemical that when absorbed into
  the body mimics, blocks, or otherwise alters
  hormone level, function, or binding and
  subsequently disrupts normal bodily functions
  including behavioral and/or strictly physiologic
  responses.

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Aquatic Ecology and Endocrine Disruption

• An individual organisms ability to better-exploit
  a resource (or group of resources) in the face of
  environmental stress and inter-specific
  competition, coupled with conservation of the
  genetic material enabling this exploitation, is
  what drives speciation.

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• Genetic conservation of traits is initiated, and
  sustained by, subtle behavioral cues for mating,
  spawning, aggression, territoriality, avoidance,
  etc.
• Any impairment of these behavioral cues or
  manifestation into physiological or morphological
  changes has the capability to stunt speciation by
  lowering fertility and fecundity.

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Endocrine Disrupting Compounds

• FAR more than what can be included in this
  presentation.
• By the time breakdown products and metabolites
  are added to the mix, iterations become
  astronomical.

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Just a Few Examples by Use Category

• Detergent Metabolites
• Fire/Flame Retardants
• Fragrances/Flavors
• Fuels/PAHs
• Herbicides/Insecticides
• Household Wastewater Compounds
• Non-Prescription Drugs
• Plasticizers/Antioxidants
• Prescription Drugs
• Steroids

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• At the landscape scale, those compounds known to
  be powerful EDCs, but are not
  environmentally-persistent, exert less of an
  effect than those persistent, but relatively
  weaker, compounds.

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Quantification and Research Design Issues One
Size Does Not Fit All
Genetic
Mechanistic Understanding
Biochemical
Physiological
Histopathological
Behavioral
Immunological
Reproductive
Bioenergetic
Assemblages
Populations
Ecological Significance
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Observational versus Controlled Studies

• True control and replication is not possible in
  the field.
• Laboratory studies with control and replication
  give up some ecological significance.

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Exposure and Causation

• Several studies have examined the effect of one
  or a very few EDCs on the physiological response
  of an organism.
• The vast magnitude of compounds in a matrix makes
  assumptions about individual compounds difficult
  to ascertain.
• Non-monotonic dose-response curves

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• With new and emerging contaminants found almost
  on a daily basis, making assumptions about
  exposure and physiologic response must always
  carry the caveat of the compounds we analyzed
  for

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Grab, Composite, or Integrated Samples?

• Problems associated with not knowing long-term
  exposure to fish or other organisms.

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Passive Organic Chemical Integrative Sampler
(POCIS) and/or Semi-Permeable Membrane Devices
(SPMDs aka fatbags)
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• Of all the tools at our disposal to study
  complex environmental issues in aquatic
  ecosystems, a sound understanding of ecological
  principles as they pertain to these ecosystems is
  the most essential.

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Quantifying Endocrine Disruption in a Threatened
and Endangered Fish Species
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• Unlike semi-arid or north-temperate regions,
  effluent-dependent waters (EDWs) in arid
  regions usually contain 100 effluent year-round.

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The Santa Cruz River Near Tucson, Arizona

• Flows from Mexico near Nogales, Sonora northward
  to Tucson, Arizona.
• The only sections with flowing water are those
  due to discharge from WWTPs.

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Roger Road WWTP

• Built in 1951.
• Treated effluent is discharged into the Santa
  Cruz River or diverted into the citys reclaimed
  water system.
• Treats the wastewater generated by a population
  of about 419,000.
• A capacity of 41 mgd and treated an average of 38
  mgd from 2004 to 2005.
• Produces secondarily-treated wastewater

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Tucson
Santa Cruz River
Roger Road WWTP
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This Study

• Laboratory study with controls, replicates, and
  randomization.
• Use fish native to the region (largely
  pollution-tolerant).
• Framework or foundation for refinement of future
  studies.
• Varying doses of effluent (treatments).
• Concentrate on long-term, persistent compounds.

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Bonytail Chub (Gila elegans)
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Control
Control
Treatment
Treatment
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Water temperature maintained between 25-29o
C. Photoperiod was maintained at 12 hours of
light and dark
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Treatment/Dosages

• Fish in raceways exposed for 3 months per
  treatment
• 1st treatment 1/3 by volume treated ww and 2/3
  water treated by RO
• 2nd treatment 2/3 by volume treated ww and 1/3
  water treated by RO
• 3rd treatment full strength treated ww

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Results
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Males - Overall
17ß-Estradiol Control (n 6) 217.3 Treatment (n
13) 547.4
11-ketotestosterone Control (n 6)
820.8 Treatment (n 13) 473.5
Vitellogenin Control (n 6) 0.09 Treatment (n
13) 0.32
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Females - Overall
11-ketotestosterone Control (n 54)
591.3 Treatment (n 47) 530.4
17ß-Estradiol Control (n 54) 568.2 Treatment
(n 47) 403.7
Vitellogenin Control (n 54) 0.18 Treatment (n
47) 0.18
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Synergistic Effects

• Ratios of primary male and female sex hormones,
  in undisturbed populations would be expected to
  have an inverse relationship i.e. as one
  increased, the other would decrease.
• We could therefore assume that major deviations
  from this inverse relationship between male and
  female primary sex hormones, could be attributed
  to impairment.

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Control Males
Treatment Males
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Control Females
Treatment Females
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• Synergism, feedback mechanisms, and non-linearity
  of bio-markers makes data reduction necessary to
  determine trends.
• Ordination is a good statistical tool but still
  assumes some degree of linear correlation as
  would occur with a typical dose-response curve.

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Males
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Females
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Summary

• Significant hormonal impairment of both sexes, as
  compared to controls, at very low concentration
  of compounds.
• This impairment could never have been determined
  in a field study.
• Commonly-used parametric analyses are often
  inadequate in determining impairment.

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Summary (cont)

• Determination of either hormonal impairment or
  endocrine disruption requires using phased
  biomarkers.
• Phase 1 Aromatase/GnRH
• Phase 2 GtH I, GtH II
• Phase 3 Sex hormones
• Phase 4 Protein development (vtg, oocyte,
  spermiation)
• Phase 5 Intersex

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Current and Future Research

• Fertility/fecundity and sex ratio/development of
  F2 generation.
• Behavior.
• Treatments using streambed sediment from affected
  EDWs.

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• This study is highly representative of the
  biological effect of endocrine-disrupting
  compounds at the landscape scale.

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Questions?