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Use
of Bioindicators for Site Monitoring Requirements
James
R. Newman, Pandion Systems, Inc., Gainesville, FL
Immunological
Alterations as Bioindicators of Environmental Health
Judith
T. Zelikoff, New York University School of Medicine,
Tuxedo, NY
Jessica Duffy, New York University School of Medicine,
Tuxedo, NY
Elizabeth Berg, New York University School of Medicine,
Tuxedo, NY
Erik Carlson, New York University School of Medicine,
Tuxedo, NY
Field
Bioindicators in Reptiles and Amphibians
John
Schaffer, Tetra Tech, Morris Plains, NJ
Selenium
as a Bioindicator of Susceptibility to Mercury Toxicity:
The “Tonic to Target” Paradigm Shift
Nicholas
V. C. Ralston, Energy and Environmental Research Center,
Grand Forks, ND
Laura J. Raymond, Energy and Environmental Research
Center, Grand Forks, ND
Genomic
Indicators of Environmental Health
Rebecca
D. Klaper, University of Wisconsin-Milwaukee, Milwaukee,
WI
Biological
Indicators for Freshwater Flow in the Tampa Bay Estuary
and Tidal Rivers
David Wade and Anthony Janicki, Janicki Environmental,
Inc., St. Petersburg, FL
Use
of Bioindicators for Site Monitoring Requirements
James R. Newman, Ph.D.,
Pandion Systems, Inc., 5200 NW 43rd Street,
Suite 102-314, Gainesville, Fl 32606-4482
The use of bioindicators
for monitoring site conditions has a long history starting
with the use of canaries by miners to monitor carbon
monoxide levels in mines.
In the early 1970s bioindicators emerged as formal
monitoring tools for soil, water and air pollution, e.g.
use of invertebrates and fish to monitor the quality of
streams as recommended by Clean
Water Act monitoring programs.
Specifically, bioindicators have been used
investigators to characterized site conditions for
research project and as formalized monitoring tools for
regulatory monitoring requirements or recommendations.
This paper will review the use of bioindicators of
soil, water and air quality conditions as part of site
regulatory site monitoring requirements and
recommendations. An analysis of past and current trends in
the use of bioindicators for site monitoring will be
presented. The
use of bioinidicators both nationally and internationally
will be discussed.
Immunological
Alterations as Bioindicators of Environmental Health
Judith T. Zelikoff, NYU School of Medicine, Dept. of
Environmental Medicine, 57 Old Forge Road, Tuxedo, NY
10987, Tel: 845-731-3528, Fax: 845-351-5472, Email: judyz@env.med.nyu.edu
Jessica Duffy, New York University School of Medicine,
Department of Environmental Medicine, 57 Old Forge Road,
Tuxedo, NY 10987, Tel: 845-731-3632, Fax: 845-351-5472
Email: jessd2000@yahoo.com
Elizabeth Berg, New York University School of Medicine,
Department of Environmental Medicine, 57 Old Forge Road,
Tuxedo, NY 10987, Email: eab289@nyu.edu
Erik Carlson, New York University School of Medicine,
Department of Environmental Medicine, 57 Old Forge Road,
Tuxedo, NY 10987, Tel: 845-731-3556, Fax: 845-351-5472,
Email: carlson@env.med.nyu.edu
Fish
represent a sensitive target for the toxic effects of most
aquatic pollutants. Because of the sensitivity of the
immune response to environmental toxicants, and its
importance for maintaining host resistance against
disease, chemical-induced immune dysfunction can be
predictive of the toxicological hazards/risks associated
with pollutant exposure. The previous establishment
of highly sensitive immune assays to enumerate these
alterations has culminated in a well-characterized battery
of endpoints that can be used successfully to predict
biological impact and adverse health outcomes in exposed
populations. Studies in this laboratory using a a variety
of laboratory-reared and feral fish species (i.e.,
Japanese medaka, bluegill, tomcod, smallmouth bass,
flounder and trout) have demonstrated that immune
parameters such as antibody-forming cell numbers,
lymphoproliferation, host resistance against infectious
pathogens and oxygen radical production can be used
successfully to assess the immunotoxicity of common
aquatic pollutants such as metals (i.e., cadmium, nickel
and seleniium), polycyclic (i.e., benzo[a]pyrene [BaP]),
and halogenated (polychlorinated biphenyls [PCB]) aromatic
hydrocarbons, pesticides (i.e., permethrin and malathion),
as well as complex environmental mixtures (i.e.,
contaminated groundwater). For example, smallmouth bass
recovered from a PCB-contaminated site demonstrated a
suppressed ability to phagocytose foreign agents, while
medaka exposed to environmentally-relevant levels of
malathion in the laboratory demonstrated reduced
resistance against infection with bacterial pathogens and
a compromised ability to produce antibodies. Such
sensitivities also have major applications in
efficacy-testing programs including those following
remediation. Information on host immunocompetence
generated from such programs could aid in management
decisions regarding the effectiveness of any remedial
activities, and the rates of recovery of affected sites.
It could be assumed that changes in directions indicating
decreased exposure/effects of affected sites precede an
improvement in the ecological health of the environment.
Thus, assays that measure immune dysfunction can serve as
rapid indicators of the direction of change in the toxic
exposure and effects at a particular monitoring site.
Funded by USACEHR Contract No. DAMD 17-99-9011 and Hudson
River Foundation Graduate Fellowship.
Field
Bioindicators in Reptiles and Amphibians
John D. Schaffer, Tetra
Tech FW, Inc., 1000 The American Road, Morris Plains, NJ
07950, Tel: 973-630-8530, Fax: 973-630-8025, Email:
jschaffer@ttfwi.com
Ecological risk assessments
have long focused on assessing exposure and characterizing
risks to higher vertebrates such as birds and mammals
based upon the historical and current toxicological
studies being conducted in field and laboratory
populations. Fish
too, have also received considerable attention given their
importance in the food chain and to human consumption.
Reptiles and amphibians have not received as much
attention and field based investigations for population
health remains limited.
An increasing toxicological literature base and
renewed interest in these vertebrate groups as indicator
species within the food chain has resulted in a greater
need for field based studies to determine the relative
health of these species in contaminated environments.
In an attempt to assess the utility of field based
observations, a screening checklist that parallels those
used for external fish necropsy was developed. A field checklist allows for consistent recording of health
and overall condition using field based observations for
individuals of the species collected.
The checklist primarily focuses on aquatic reptile
species as a majority of contaminated sites have aquatic
habitats with contaminated surface water and sediments.
The primary group focused upon was the freshwater
chelonians, which are long lived, and thus prone to
prolonged exposure to bioaccumulating contaminants in
local food chains.
Selenium
as a Bioindicator of Susceptibility to Mercury Toxicity:
The “Tonic to Target” Paradigm Shift
Nicholas V. C. Ralston, Ph.D., Energy and Environmental
Research Center, Post Office Box 9018, 15 North 23rd
Street, Grand Forks, ND 58202-9018, Tel: 701-777-5066,
Fax:701-777-5181, Email: nralston@undeerc.org
Laura J. Raymond, Ph.D. Energy and Environmental Research
Center, Post Office Box 9018, 15 North 23rd Street, Grand
Forks, ND 58202-9018, Tel: 701-777-5156, Fax:701-777-5181,
Email: lraymond@undeerc.org
Measuring
the amount of mercury present in the environment or food
sources may provide an inadequate reflection of potential
health risks if the protective effect of selenium is not
also considered. Selenide
has an extremely high affinity for mercury (kd
10-45). As
a result, Hg-Se complexes readily form, especially in
intracellular reducing environments.
This interaction has also been assumed to have a
physiological “protective” effect whereby supplemental
Se prevents negative effects in animals fed otherwise
toxic amounts of Hg. Likewise, numerous studies indicate
that the Se naturally present in foods, such as fish and
seafood, provides this physiological protection against Hg
toxicity. However, rather than being a protective
“tonic”, selenium may instead be the “target” of
Hg toxicity, whereby Hg sequesters Se. Studies have shown
Hg exposure reduces the activity of enzymes that require
the primary amino acid, selenocysteine, at their active
site. The additional Se may simply support continued
Se-dependent enzyme synthesis. Similarly, Se addition to
aquatic ecosystems has been found to enhance Hg retirement
and reduce Hg bioaccumulation through Hg-Se formation. Since Se suspended in the water column will be in an oxidized
state that is unlikely to bind Hg, the mechanism of Hg-Se
formation appears likely to be biologically mediated.
The Hg-Se interaction is apparent throughout the
mercury cycle, influencing its transport, biogeochemical
exposure, bioavailability, toxicological consequences and
remediation. Further
research is necessary to understand the molecular
mechanisms responsible for Se’s protective effects
against Hg toxicity and identify populations which may be
protected or at greater risk.
Genomic
Indicators of Environmental Health
Rebecca
D. Klaper, Shaw Assistant Scientist, Assistant Director,
Center for Water Security, Great Lakes WATER Institute, University of
Wisconsin-Milwaukee, Tel: 414-382-1713, Email: rklaper@uwm.edu
Traditional
biological indicators to measure environmental health
require destructive sampling, rely on population and
community level responses, and are retrospective in their
assessment in that they attempt to link current declines
in populations to past measurements of stressors.
In addition it is difficult to separate the
exposure and effects of the multiple factors to which an
organism may be exposed in the environment. Genomic
technologies are beginning to offer a method to overcome
these obstacles in risk assessment. By measuring changes
in gene expression (the production of mRNA or proteins) of
hundreds of genes at a time, genomics can provide a
fingerprint for each stressor, measure effects at low
levels of exposure, and identify changes in physiology
before a larger physical response is detected. As an
example, fathead minnows that were fed methyl mercury
contaminated diet were analyzed for changes in gene
expression to liver and gonad tissues. At very low levels
of mercury contamination changes in the expression of
genes associated with reproduction, nervous system
function, and immune response were observed. A companion
study found a decrease in overall fitness of females and a
change in hormone levels of male fish with increasing
exposure. Linking molecular, hormonal and fitness level
responses will ultimately be necessary to initially
validate molecular indicators as biomarkers. However, once
validated these measurements will provide a sensitive,
rapid way to test for exposure and possible fitness
effects within a population. Genomics may also provide a
way to link the response of multiple species in the
environment. Other projects using genomics of native
species, from sturgeon to Daphnia will be discussed.
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