The Toxicologist - Society of Toxicology

432 AN INTEGRATED LABORATORY AND FIELD
ASSESSMENT OF SELECT ENDOCRINE DISRUPTORS
IN THE PUGET SOUND REGION.
I. Schultz. Battelle PND-MSL, Sequim, WA.
The contamination of aquatic environments with endocrine disruptors (EDs) is
highly variable dependent upon source input rates, natural degradation processes
and local hydrologic conditions among other factors. This creates challenges for environmental
monitoring programs, which need frequent sampling to adequately assess
the occurrence of ED contamination. Thus, there is potential for underestimating
the extent of ED contamination and its impact aquatic organisms. In this
study, we monitored four different streams in the greater Puget Sound region of
Washington State for the occurrence of estrogenic contaminants and for selective
serotonin reuptake inhibitor (SSRI) type pharmaceuticals. We also assessed whether
exposure levels were sufficient to impact fish reproduction. Our field sites were selected
based on the predominant type of contamination: dairy farm runoff, municipal
treated sewage or stormwater runoff. Our experimental design used an integrated
approach employing grab samples of water and passive sampling devices
deployed for several weeks at each stream site. We also placed caged, sexually mature
rainbow trout at each site. The trout were placed in the streams for up to eight
weeks and then subsequently spawned to assess fertility and embryo survival. The
latter has been demonstrated in past laboratory studies to be the most sensitive toxicological
endpoint in fish exposed to estrogens. At one site, both estrogens (estradiol
and estrone) and two SSRIs (fluoxetine and Sertraline) were detected at levels
up to 30 PPM. Caged trout at this site also exhibited vitellogenin induction and reproductive
failure. The full results of this study will be presented and the significance
towards monitoring efforts of endocrine disruptors discussed.
433 ENDOCRINE DISRUPTION IN A CALIFORNIA
ESTUARY: LINKING RECEPTOR BINDING TO
POPULATION LEVEL EFFECTS.
S. M. Brander and G. N. Cherr. Environmental Toxicology, University of California
Davis, Bodega Marine Lab, Bodega Bay, CA.
Estrogenic & androgenic endocrine disrupting compounds (EDCs) are widespread
in the environment and are known to damage the reproductive systems of fishes.
Deleterious EDC effects include female reproductive protein production in male
fish, reduced female egg production, & altered sex ratios. A large body of work exists
on EDC effects in commonly used laboratory species (zebrafish); however fewer
studies have considered resident species that inhabit areas of concern, particularly
estuaries. Estuarine habitats, such as Suisun Marsh in CA, serve both as a nursery
and as vital habitat for a number of threatened fish species. Our work utilizes the
inland silverside (Menidia beryllina), a euryhaline resident of estuaries on the
Atlantic, Pacific and Gulf coasts, as an indicator of EDC exposure. Our investigation
of several sites exposed to varied sources of confirmed EDCs has proceeded in
a three-tiered manner. First, solid-phase extracts of site water samples produce significant
evidence of binding to both the estrogen receptor (ER) and androgen receptor
(AR) using the CALUX assay (chemical-activated luciferase gene expression)
with ER and AR transfected cell lines. Second, immunoanalysis of blood samples
reveals that wild males collected from Suisun Marsh express choriogenin (egg shell
protein); data from an outplanting experiment suggest that the level of expression
at marsh sites is significantly greater than laboratory controls and is equivalent at
sites exposed to treated wastewater effluent, urban run-off or ranch run-off. Third,
field collections reveal that sites within the marsh exposed to different run-off types
exhibited significantly different sex ratios that persisted through the 2009 reproductive
season. These results suggest that receptor binding effects may scale up to
affect individual- and population-level consequences. Ongoing work is examining
the demographic consequences of these effects and whether they differ among
EDC types. We ultimately hope to establish Menidia beryllina as a new model
species for EDC research.
434 ACETYLCHOLINESTERASE AND METALLOTHIONEIN
IN OYSTERS (CRASSOSTREA CORTEZIENSIS) FROM A
SUBTROPICAL MEXICAN PACIFIC.
Y. Y. Bernal-Hernández, M. Medina-Díaz, L. Robledo-Marenco, J. B.
Velázquez-Fernández, I. Girón-Pérez, L. Ortega-Cervantes, W. Maldonado-
Vázquez, C. A. González-Arias and E. Rojas-García. Universidad Autónoma de
Nayarit, Tepic, Mexico. Sponsor: B. Quintanilla-Vega.
Acetylcholinesterase and metallotionein in oysters (Crassostrea corteziensis) from a
subtropical Mexican Pacific Mollusk bivalves, such as oysters are commonly used in
environmental monitoring programs because of their wide geographical distribution,
great sensitivity to environmental pollutants and high accumulation rate of
anthropogenic chemicals. Both acetylcholinesterase (AChE) activity and metallothionein
(MT’s) content are biomarkers that indicate the presence of anticholinesterasic
compounds (like organophosphorus and carbamate pesticides) and
metals, respectively. Boca de Camichin, Nayarit, is a subtropical Mexican Pacific estuary
with biodiversity and social-economical importance due to the oyster production.
The aim of this study was to evaluate AChE activity and MT’s content in oysters
(Crassostrea corteziensis) collected from Boca de Camichín estuary, as
biomarkers of effect and exposure to pesticides and heavy metals, respectively.
AChE activity was determined in gills according to Ellman (1961) method. A specific
AChE activity was obtained using 1 mM iso-OMPA. MT’s content was evaluated
according to Viarengo et al. (1997) and Kimura et al. (1979) methods. Positive
and negative controls were carried out for each biomarker. AChE activity was 65%
lower in oysters from Boca de Camichin than in negative control organisms.
Contrastingly, MT’s content in collected organisms was not statistically different
from that in control organisms. This work shows that AChE activity and MT’s content
in oysters could be used as early biomarkers of pesticide or metal exposure, in
aquatic environments.
435 APPLICATION OF HIGH ENERGY ELECTRON BEAM
AND CHEMICAL OXIDANTS TO DESTROY
ESTROGENIC ACTIVITY IN WASTEWATER EFFLUENT
AND BIOSOLIDS.
C. Rambo 1, 2 , L. Xiangrong 1, 3 , P. Srisawat 4 , K. Brady 4 , P. R. Jesudhasan 2 , S.
Safe 1, 3 , R. Reimers 4 and S. D. Pillai 2, 1 . 1 Interdisciplinary Faculty of Toxicology,
Texas A&M University, College Station, TX, 2 Food Safety & Environmental
Microbiology Program, Texas A&M University, College Station, TX, 3 Veterinary
Physiology & Pharmacology, Texas A&M University, College Station, TX and
4
Environmental Health Sciences, Tulane University, New Orleans, LA.
Wastewater effluent and biosolids from municipal wastewater treatment facilities
can contain a variety of infectious microorganisms as well as man-made and natural
chemical compounds and their metabolites. This can create health risks for both
humans and other animals. According to the U.S. EPA and WHO, endocrine disrupting
chemicals, such as estrogen and its metabolites, have become a critical
emerging environmental concern due to their ability to disrupt normal endocrine
function. The objective of this study was to determine the efficacy of high energy
(10MeV) electron beam (E-Beam) and chemical oxidants (ferrate and chlorine
dioxide) to break down estrogenic compounds in wastewater effluent and biosolids.
Wastewater effluent and biosolids samples were collected from wastewater treatment
plants. The samples were spiked with 17-β-estradiol and either irradiated
using E-Beam (doses ranged from 2 to 12 kGy) and/or treated with different concentrations
of ferrate and chlorine dioxide. The estrogenic activity was measured
using two different in vitro bioassays, the breast cancer cell line ZR-75 and the YES
(Yeast Estrogen Screening) assay. The reduction of estrogenic activity in wastewater
after E-Beam irradiation ranged from 71-79% depending on the dose. These results
suggest that high energy E-Beam is capable of destroying the estrogenic activity associated
with wastewater effluent. E-Beam irradiation and chlorine dioxide were
less successful at reducing estrogenic activity in biosolids. Ferrate was the only treatment
that was able to reduce estrogenic activity in biosolids. Further research is
needed to optimize the different treatments and identify the potential end-products
of the oxidation process.
436 THE RELATIONSHIP BETWEEN MASCULINIZED
FEMALE QUEEN CONCH (STROMBUS GIGAS) AND
TRIBUTYLTIN-BASED ANTIFOULING PAINTS IN
COASTAL WATERS OF THE BRITISH VIRGIN ISLANDS.
O. S. Phillip 1 , C. O’Neal 1 and K. Thomas 2 . 1 Marine Biology, H. Lavity Stoutt
Community College, Road Town, Tortola, BVI, United Kingdom and 2 Environment,
Fisheries, and Aquaculture Science, Burnham on Crouch, Essex, United Kingdom.
Sponsor: D. Hood.
Organotin compounds are lipophilic compounds that were once used extensively in
the production of antifouling biocides for ships and fishing nets, wood preservatives,
agricultural fungicides and pesticides. The widespread uses of these products
have resulted in the release of increasing amounts of organotins into the environment,
which has proven to be highly toxic to marine organisms. In aquatic invertebrates,
particularly marine gastropods, organotin compounds, such as tributyltin
(TBT), induce the superimposition of male-type genital organs (penis and vas deferens)
on female gastropods (termed imposex), at very low concentrations.
However, the process of imposex development is not clearly understood. The purpose
of this study was to investigate the role of TBT in the masculinization of the
female queen conch, Strombus gigas, in the coastal marine environment. Samples
of the queen conch were obtained from three sites around the island of Tortola,
94 SOT 2010 ANNUAL MEETING