Ecotoxicology

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Ecotoxicology

• Ali B. Ishaque

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Course Outline

• SECTION 1 GENERAL
• Definition
• Ecotoxicology Vrs Classical Toxicology
• Historical need for ecotoxicology
• Current Need for Ecotoxicological Expertise
• Scientific Goal
• Technological goal
• Practical Goal

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Course Outline

• Environmental contaminants
• Environmental Fate of Contaminants
• Contaminant Partitioning
• Degradation
• Major Classes of Contaminants
• Metals and Metalloids
• Inorganic Gases
• Nutrients
• Organic Compounds
• Organometallic Compounds
• Emerging Contaminants of Concern

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Course Outline

• SECTION 2 Bioaccumulation
• Uptake.
• Reaction Order
• Biotransformation and Detoxification,
• General
• Metals and Metal10ids
• Organic Compounds
• Elimination
• Elimination Mechanisms
• Modeling Elimination
• Accumulation

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Course Outline

• Factors Influencing Bioaccumulation
• Bioavailability
• Chemical Qualities Influencing Bioavailability
• Inorganic Contaminants
• Bioavailability from Water
• Bioavailability from Solid Phases
• Organic Contaminants
• Bioavailability from Water
• Bioavailability from Solid Phases
• Biological Qualities Influencing Bioaccumulation
• Temperature-Influenced Processes
• Allometry
• Other Factors

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Course Outline

• Bioaccumulation from Food and Trophic Transfer
• Quantifying Bioaccumulation from Food
• Assimilation from Food
• Trophic Transfer
• Defining Trophic Position
• Estimating Trophic Transfer
• Inorganic Contaminants
• Metals and Metalloids
• Radionuclides
• Organic Compounds

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Course Outline

• SECTION 3Toxicant Effects
• Molecular Effects and Biomarkers
• Organic Compound Detoxification
• Phase I
• Phase II
• Metallothioneins
• Stress Proteins
• Oxidative Stress and Antioxidant Response
• DNA Modification
• Enzyme Dysfunction and Substrate Pool Shifts

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Course Outline

• Cells, Tissues, and Organs
• General Cytotoxicity and Histopathology
• Necrosis
• Inflammation
• Other General Effects
• Gene and Chromosome Damage
• Cancer
• Gills as an Example

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Course Outline

• Sublethal Effects to Individuals
• General
• Selyean Stress
• Growth
• Development
• Developmental Toxicity and Teratology
• Sexual Characteristics
• Developmental Stability
• Reproduction
• Physiology
• Behavior
• Detecting Sublethal Effects

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Course Outline

• Acute and Chronic Lethal Effects to Individuals
• General
• Overview
• Acute, Chronic, and Life-Stage Lethality
• Test Types
• Dose-Response
• Basis for Dose-Response Models
• Fitting Data to Dose-Response Models
• Incipiency
• Mixture Models

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Course Outline

• Survival Time
• Basis for Time-Response Models
• Fitting Survival-Time Data
• Incipiency
• Mixture Models
• Factors Influencing Lethality
• Biotic Qualities
• Abiotic Qualities

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Course Outline

• Effects on Populations
• Epidemiology
• Population Dynamics and Demography
• General Population Response
• Metapopulation Dynamics
• Demographic Change
• Energy Allocation by Individuals in Populations
• Population Genetics
• Change in Genetic Qualities
• Acquisition of Tolerance
• Measuring and Interpreting Genetic Change

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Course Outline

• Effects to Communities and Ecosystems
• Overview
• Interactions Involving Two or a Few Species
• Predation and Grazing
• Competition
• Community Qualities
• Structure
• Community Indices
• Approaches to Measuring Community Structure
• Function
• Ecosystem Qualities

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Course Outline

• Landscape to Global Effects
• Landscapes and Regions
• Continents and Hemispheres
• Biosphere
• Global Movement of Persistent Organic Pollutants
  
• Global Warming

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Course Outline

• SECTION 4 Risk from Pollutants
• Risk Assessment of Contaminants
• Logic of Risk Assessment
• Expressions of Risk
• Risk Assessment
• Human Risk Assessment
• Hazard Identification (Data Collection and Data
  Evaluation)
• Exposure Assessment
• Dose-Response Assessment
• Risk Characterization

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Course Outline

• Ecological Risk Assessment
• Problem Formulation
• Analysis
• Exposure Characterization
• Ecological Effects Characterization
• Risk Characterization

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Course Outline

• Risks from Exposure to Radiation
• Fundamentals of Radioactivity
• Types of Radiation
• Concentrations, Decay Constants, and Half-Life
• Radionuclide Detection
• Effects
• Dose
• Environmental Transport
• Models Using Rate Constants
• Screening Level Models

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Course Outline

• Models Using Equilibrium Conditions and
  Dose-Conversion Factors
• Inhalation Pathway
• Ingestion Pathway
• External Irradiation
• Derivation of Risk Factors
• Epidemiological Studies
• Dose-Response Relationships
• Threshold Option
• Linear versus Linear-Quadratic
• Currently Accepted Risk Factors
• Risks to Humans from Exposure to Radiation
• Ecological Effects from Radioactive Contamination
  
• Confidence in Risk Analyses

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Recommended textbooks

• Newman and Unger Fundamentals of ecotoxicology,
  Second edition. Lewis Publishers, Boca Raton .
• Walker, Hopkin, Sibly Peakall (2006) Principles
  of ecotoxicology,Third Edition . Taylor
  Francis, London.

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Definition Reference

• Environmental Toxicology
• Duffus (1980) the study of the effects of toxic
  substances occurring in both natural and man-made
  environments
• Landis and Yu (1995) the study of the impacts of
  pollutants upon the structure and function of
  ecological systems (from molecular to ecosystem)

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Definition Reference

• Ecotoxicology
• Truhaut (1977) the branch of toxicology
  concerned with the study of toxic effects, caused
  by natural and synthetic pollutants, to the
  constituents of ecosystems, animals (including
  human), vegetable and microbial, in an integrated
  context
• Moriarty (1983) the natural extension from
  toxicology, the science of poisons on individual
  organisms, to the ecological effects of
  pollutants

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Definition Reference

• Levin et al. (1989) the science that seeks to
  predict the impacts of chemicals upon ecosystems
  Cairns and Mount (1990) the study of the fate
  and effect of toxic agents in ecosystems
• Jorgensen (1990) the science of toxic substances
  in the environment and their impact on living
  organisms
• Suter (1993) the study of toxic effects on
  nonhuman organisms, populations, and communities

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Definition Reference

• Shane (1994) the study of the fate and effect of
  a toxic compound on an ecosystem
• Forbes and Forbes (1994) the field of study
  which integrates the ecological and toxicological
  effects of chemical pollutants on populations,
  communities, and ecosystems with the fate
  (transport, transformation, and breakdown) of
  such pollutants in the environment
• Hoffman et al. (1995) the science of predicting
  effects of potentially toxic agents on natural
  ecosystems and nontarget species

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Ecotoxicology

• The branch of Environmental Toxicology concerned
  with the study of toxic effects, caused by stable
  chemical stressors (natural and synthetic) on
  the biosphere and constituents of the biosphere

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Ecotoxicology

• As a tool, Ecotoxicology is based on four-part
  process
• The release of a chemical into the environment
• The transport of the chemical into biota, with or
  without chemical transformation
• The exposure of the chemical to one or more
  target organisms and
• The response of biosphere and constituents of the
  biosphere to the chemical exposure

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Definition Classical Toxicology

• On the contrary, Classical Toxicology has the
  primarily concerned with toxic effects of
  chemicals and radiation on different levels of
  biological organization from subcellular to the
  individual organisms but with a primary focus on
  humans
• It covers the uptake, distribution, metabolism
  and excretion of chemicals by individual
  organisms
• (www.cambridge.org)

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Hypothesis of Gaia Earth as a superorganism
The entire range of living matter on Earth from
whales to viruses and from oaks to algae could be
regarded as constituting a single living entity
capable of maintaining the Earth's atmosphere to
suit its overall needs and endowed with faculties
and powers far beyond those of its constituent
parts Dr James Lovelock - Gaia - A New Look at
Life on Earth
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Concept of the biosphere
Hydrosphere
Biosphere
Lithosphere
Atmosphere
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BIOSPHERE

• It has
• Biotic components
• plants, animals (including humans),
• microbial life (fungi, protozoans, bacteria)
• Abiotic components
• air
• Water
• soil

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ECOTOXICOLOGY A SYNTHETIC SCIENCE

• Ecotoxicology draws from many disciplines
• Physical and Life Sciences
• Questions of effect should be posed from all
  levels of biological organization
• molecular (e.g., enzyme inactivation by a
  contaminant)
• to the population (e.g., local extinction)
• to the biosphere (e.g. global warming)
• Also questions of fate and transport should be
  addressed from levels of physical scale
• chemical (e.g., dissolved metal speciation)
• to the habitat (e.g., contaminant accumulation in
  depositional habitats)
• to the biosphere (e.g., global distillation of
  volatile pesticides).

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PHYSICAL SCIENCES Disciplines contributing to understanding abiotic interactions
LIFE SCIENCES Disciplines contributing to
understanding biotic interactions
Biosphere
Geology Oceanography
Global Ecology
Landscape
Atmospheric Chemistry Climatology
Landscape Ecology Systems Ecology
Env.Microbiology
Ecosystem
Geography Biogeochemistry
Community Ecology Metapopulation Biology
Community
Habitat
Hydrology Soil Science Sedimentology Colloid Chemistry
Population Biology and Genetics Epidemiology
Population
Microhabitat
Individual
Physiology/Anatomy BehaviorDeve!.Biology
Organ system Organ Tissue Cell Organelle Biomolecu
le
Phase association
Teratology Neurology Pharmacology Endocrinology Immunology Oncology Biochem./Biophys. Molecular Genetics
Physical Chemistry Analytical Chemistry Organic Chemistry Inorganic Chemistry
Chemistry
Hierarchical organization of topics addressed by
ecotoxicology. Important interactions, denoted by
lines connecting components, occur between biotic
and abiotic Components
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ECOTOXICOLOGY A SYNTHETIC SCIENCE

• In ecotoxicology all levels of biological
  hierarchy are equally important for effective
  environmental stewardship.
• Although all levels are equally important, they
  contribute differently to our efforts and
  understanding.

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• Next Slide Provides hierarchical organization of
  topics in ecotoxicology relative to
• ecological relevance,
• general tractability,
• ability to assign causation,
• general use of knowledge,
• temporal context of consequence, and
• temporal sensitivity of response

• Lower level Issues are more tractable and have
  more potential for linkage to a specific cause
  than effects at higher levels such as the
  biosphere.

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HIGH
LOW
Biosphere
Ecosystem
Ecological relevance Response duration Long-term
consequences
Community
Population
Individual
Tractability Ability to assign causation Pro-activ
ity in use of knowledge
Organ system Organ Tissue Cell Organelle Biomolecu
le
HIGH
LOW
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Ecological relevance, general tractability,
ability to assign causation, general use of
knowledge, temporal context of consequence, and
temporal sensitivity of response.

• Lower level effects are highly tractable and
  sensitive
• E.g. biochemical effects of toxicants Depressed
  b-aminolevulinic acid dehydratase (ALAD) activity
  in red blood and lead exposure
• easily measured
• Direct linkage.
• Higher level effects have highly ecological
  relevance
• e.g. Ozone depletion over Antarctica and
  chlorofluorocarbon release (CFCs)
• difficult to measure
• difficult causal linkage with a high degree of
  certainty.
• Hence lower levels effects are used more readily
  in a proactive manner (i.e. early warning
  systems) while higher levels effects are useful
  in documenting or reacting to an existing
  problem.

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Tractability Ability to assign causation

• Ecological relevance Lower vrs Higher Levels
• lower levels effects more ambiguous than effects
  at higher levels of organization.
• E.g. 50 reduction in species richness gives
  clear indication of diminished health of an
  ecological community
• 50 increase in metallothionein in adults of an
  indicator species provides an equivocal
  indication of the health of populations in the
  associated community.
• Relatively, lower levels effects tend to occur
  more rapidly after the stressor appears and
  disappear more quickly after it is removed.
• Hence information from all relevant levels of
  biological organization should be combined to
  achieve a desirable outcome.

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Ecotoxicologist Goals

• The broader goal of Ecotoxicology is preserving
  the structure and functioning (physiology) of
  biosphere and not the protection of individual
  organism or a specific population.
• This broader goal is divided into 3 distinct yet
  overlapping goals by ecotoxicologists
• Scientific goal
• Technological goal
• Practical goal

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• SCIENTIFIC GOAL
• is to organize knowledge, based on explanatory
  principles, about contaminants in the biosphere
  and their effects.
• Product explanatory principles or paradigms
  about which facts are organized. These paradigms
  (generally accepted concepts in a healthy science
  that withstood rigorous testing and, as a result,
  hold enhanced status as explanations) are learned
  by members of a discipline and define the major
  directions of inquiry in the field.

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• TECHNOLOGICAL GOAL
• The goal of ecotoxicology as a technology is to
  develop and apply tools and methods to acquire a
  better understanding of contaminant fate and
  effects in the biosphere.
• Product Procedures, Protocols, analytical
  instrumentation (MS, GC, GC-MS) and computational
  methods
• The link between science and practice

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Ecotoxicology Practical goals

• Goal application of available knowledge, tools,
  and procedures to solving or documenting specific
  problems.
• Employs technology to solve or document a
  particular environmental situation
• Products criteria, standards and guidelines for
  practice, clean-up and pollutant containment
  solutions, etc.

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Present balance among scientific, technological,
and practical components of ecotoxicology.
Relative amount of effort in each is reflected by
area on the plots

Long
Time of Benefit
Other Technologies
Other Laws Regulations
Short
LOCAL
GLOBAL
VALUE
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Ideal balance among scientific, technological,
and practical components of ecotoxicology.
Relative amount of effort in each is reflected by
area on the plots

Long
Time of Benefit
Short
LOCAL
GLOBAL
VALUE
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HISTORIC NEED FOR ECOTOXICOLOGY

• Several incidences of environmental pollution
• Chemical
• Nuclear

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HISTORIC NEED Heavy Metal Poisoning

• Two horrible epidemics from contaminated food had
  occurred in Japan.
• 1950s, organic mercury was transferred through
  the marine foodweb to poison hundreds of people.
  Nearly a thousand people fell victim to Minamata
  Disease before Chisso Corporation halted
  discharge of mercury into Minamata Bay.
• From 1940 to 1960, Japanese in the Toyama
  Prefecture were poisoned by cadmium in their
  rice. This itai-itai disease was linked to
  irrigation water contaminated from metal mine
  wastes.
• itai-itai, reflects the extreme joint pain
  associated with the disease and literally means
  "ouch-ouch."

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HISTORIC NEED NUCLEAR POLLUTION

• 1945,
• Open air testing of nuclear weapons at
  Alamogordo, New Mexico,
• Nuclear bombs Hiroshima and Nagasaki.
• Nine years later,
• the "Project Bravo" bomb exploded at Bikini
  Atoll,
• Several thousands square kilometers of ocean,
  islands and Lucky Dragon (fishing vessel) were
  affected
• Hemispheric dispersal unexpected accumulation of
  fission products in foodstuffs from these and
  subsequent detonations resulted in increase
  concern about possible long-term effects to
  humans.
• Human body burdens of 137Cesium increased rapidly
  worldwide Slowly decreased as the U.S., former
  Soviet Union, France, and China ceased open air
  testing1960 to 1965

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HISTORIC NEED NUCLEAR POLLUTION

• Radioactive iodine (I311 ) was released (20,000
  curies) to the northwest coast of England due to
  fire outbreak in the Windscale plutonium
  processing unit
• Radioactive iodine concentrates in the thyroid,
  causing cancer.
• Uptake by cattle through feedlots accumulates in
  thyroids of humans after consumption of dairy
  products.
• Secret Soviet military plutonium processing plant
  ("Chelyabinsk 40") secretly discharged 120
  million curies to a nearby lake and enough down
  the Techa River to induce radiation poisoning in
  citizens living downriver.
• September of 1957, a storage tank explosion at
  Chelyabinsk 40 released 18 million curies of
  radioactive material and forced the evacuation of
  approximately 11,000 people .

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HISTORIC NEED NUCLEAR POLLUTION

• From 1944 to 1966, releases from the U.S. Atomic
  Energy Commission's Hanford Site in Washington
  State were kept from the general public.
• Between 1944 and 1947, the complex released 440
  thousand curies of radioactive iodine (I311 )
  into the atmosphere.
• May 12, 1963 at the Hanford K-East reactor,
  20,000 curies materials released to the Columbia
  River.

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HISTORIC NEED Concern about pollutant effects on
nonhuman species.

• Pesticides such as DDT (dichlorodiphenyltrichloroe
  thane or 2,2-bis-p- chlorophenyl-I,I,I-trichloro
  ethane) accumulated in wildlife to alarming
  concentrations, resulting in direct toxicity and
  sublethal effects.
• From 1957 to 1960 the deaths of Western grebes
  (Aechmophorus occidentalis) from bioaccumulation
  of the pesticide, DDD 1-1 dichloro-2,2-bisp-chlor
  ophenyl ethane) from a freshwater foodchain
  (Clear Lake, California).
• These pesticides accumulated in the brain until
  enough was present to cause axonic dysfunction
  and death.

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DDT FACTS SHEET
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HISTORIC NEED Concern about pollutant effects on
nonhuman species.

• Silent Spring (1962) by Rachel Carson,
• drew public attention to these and less obvious
  consequences of pesticide accumulation in
  wildlife.
• DDT and DDE (dichlorodichloroethylene or
  1,1-dichloro-2,2-bis-p-chlorophenyl -ethene)
• relatively nontoxic to humans but
• inhibit Ca dependent ATPases in the shell gland
  of birds resulting in shell thinning and
  increased risk of egg damage after being laid.
• Birds at higher trophic levels extremely
  vulnerable because DDT and its degradation
  product DDE are relatively resistant to
  degradation and accumulate in lipids.

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HISTORIC NEED Concern about pollutant effects on
nonhuman species

• Downward trends for falcons (Falco peregrinus)
  and other raptors in the United Kingdom.
• Reproduction of brown pelicans (Pelecanus
  occidentalis) on the South Carolina coast from
  1969 to 1972 fell below that needed to maintain
  the population (Hall, 1987).

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HISTORIC NEED Concern about pollutant effects on
nonhuman species

• Reproductive failure of raptors and fish-eating
  birds became a widespread phenomenon.
• The average number of offspring per pair of
  osprey (Pandion haliaetus) nesting on Long Island
  Sound dropped from 1.71 young/nest (1938-1942) to
  only 0.07 to 0.40 young/nest by the mid-1960s.
• Reproductive success of raptor populations
  decreased in Alaska and other regions of the U.S.
  (Hickey and Anderson, 1968).

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HISTORIC NEED Paradigm Shift

• Two watershed events that most captured the
  public's attention and resulted in a paradigm
  shift-
• Dilution paradigm the solution to pollution is
  dilution
• To Boomerang paradigm what you throwaway can
  come back and hurt you
• Were Minamata disease
• DDT accumulation in raptors and fish-eating
  birds.
• They drew some attention away from giddy
  industrialization Green Revolution to the
  consequences of ignoring pollutants in ecological
  systems.
• They were among the first issues to give impetus
  to the Science of Ecotoxicology.

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Is Dilution the Solution to Pollution?
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CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• It is expected that these mistakes made earlier
  in the techno-industrial revolution will not be
  repeated but this is not the case.
• Environmental problems continue to occur despite
  our increased awareness and complex regulations.
• Indeed, problems seem to extend more and more
  frequently to transnational and global scales.

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CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE
Global distillation (GRASS HOPPER EFFECT)
PCBs, pesticides (DDT, lindane, toxaphene,
chlordane), heavy metals (Hg, Cd)
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CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE
Global distillation (GRASS HOPPER EFFECT)
PCBs, pesticides (DDT, lindane, toxaphene,
chlordane), heavy metals (Hg, Cd)
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CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• Nuclear materials still require attention and
  money expenditure.
• March 28, 1979 Melting of the core of Three Mile
  Island Reactor Unit 2 (Harrisburg, PA) releasing
  approximately 3 curies of radiation and incurring
  an estimated 965 million in cleanup costs
• April 26, 1986 The largest radioactive release
  in history (301 million curies) occurred in the
  Ukraine nearly 30 years after the Chelyabinsk 40
  explosion
• 1995 The French briefly resumed underground
  testing of nuclear devices in Micronesia despite
  worldwide protest.
• In late 2001, Afghan members of the al-Qaeda were
  making vague threats about detonating a dirty
  nuclear weapon.
• Pakistan and India are rattling their nuclear
  sabers at each other, prompting pundits to
  discuss the consequences of a nuclear exchange
  between these two countries.

59
CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• Chemical wastes continue to require attention and
  funds.
• A myriad of Soviet environmental issues remain as
  part of the Cold War legacy
• IMPOSEX Tributyltin (TBT), a widely-applied
  antifouling agent in marine paints, has harmed
  estuarine molluscs throughout the world .
• Mercury levels in fish and game remain a concern
  with new sources appearing such as mercury used
  for South American gold mining
• Subsurface agricultural drainage in the San
  Joaquin Valley of California brought selenium in
  the Kesterson Reservoir and Volta Wildlife Area
  to concentrations causing avian reproductive
  failure.

60
CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• Efforts to reduce lead in products such as
  gasoline and lead shot have only been effective
  since the late 1970s.
• Even into the 1980s, debate continued about
  effects of lead and the need for federal
  regulation
• December 2, 1984, a storage tank at a Union
  Carbide pesticide plant (Bhopal, India) exploded
  and released a cloud of methyl isocyanate killing
  2,000 people and harming an estimated 200,000
  more.

61
CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• March 16, 1978
• Amoco Cadiz supertanker ran aground at Portsall
  (France) and released 200,000 tons of crude oil.
• March 24, 1989
• Exxon Valdez spilled 41,340 m3 of crude oil into
  Prince William Sound. The oil covered an
  estimated 30,000 km2 of Alaskan shoreline and
  offshore waters.
• August 2, 1990 -February 26,1991 (1st Gulf War)
• largest deliberate oil spilled by Iraqi troops
  occupying Kuwait.
• Half a million tons of crude oil from the Mina
  AI-Ahmadi oil terminal were pumped into the
  Arabian Gulf.
• Plumes of contaminating smoke from the
  intentional ignition of Kuwaiti oil wells by the
  Iraqi troops were visible from space .

62
CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• Other more diffuse, but incrementally more
  damaging, events also require expertise in
  Ecotoxicology.
• Arabian Gulf receives 160,000 tons of oil
  annually from leaks and spills.
• Between1970 to 1989 Average number of oil spills
  and volume per spill in or around U.S. waters
  were 9,246 and 47,000 m3, respectively, with no
  obvious downward trend in either through time.
• At the time Rachel Carson was writing Silent
  Spring annual production of synthetic organic
  chemicals was 43.9 billion kg.
• By 1970, it had reached 145.1 billion kg.

63
CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• By 1985, U.S. use of pesticides roughly doubled
  from the 227 million kg used in 1964.
• Many persistent pesticides restricted in
  developed countries are still used in the Third
  World (e.g. DDT).
• Acid rain is now a transnational problem damaging
  both aquatic and terrestrial ecosystems.
• Chlorofluorocarbons (CFCs) used as propellants
  and coolants have been linked to ozone depletion
  in the stratosphere and since 1987efforts have
  being made to greatly reduce their use .

64
CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• Emerging concern New chemicals contaminants
  previously ignored are currently discharged in
  large quantities
• During the last few years ecotoxicologists have
  begun to take notice of potentially widespread
  impacts of these chemicals in natural systems
• E.g. Identified brominated, retardants, synthetic
  estrogens, alkylphenol ethoxylates and their
  degradation products, manufactured antimicrobial
  products, and constituents of personal-care
  products

65
CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• Despite the 1987 Montreal Protocol (with
  signatures from 70 countries including the U.S.)
  that calls for complete elimination of CFC use by
  2000, efforts by lawmakers were in the mid-1990s
  to delay, and perhaps avoid, any U.S. reduction
  of CFC emissions.
• These problems does not imply that
  techno-industrial advancement is incompatible
  with environmental and human health.
• It rather demonstrates two simple points.
• First, about 50 years ago, the dilution paradigm
  failed with clearly unacceptable consequences to
  human health and ecological systems.
• Second, expertise in ecotoxicology is now
  critical to our wellbeing.

66
CURRENT NEED FOR ECOTOXICOLOGICAL EXPERTISE

• Hence consideration of non market goods and
  services, and natural capital must be
  incorporated into decisions.
• Such services provided pro bono by nature are
  estimated to be in the range of 33 trillion
  annually, twice the annual gross domestic product
  of the earth's 194 countries.
• Complex and costly environmental regulations save
  human lives and allow responsible environmental
  stewardship

67
Human Activities Reshaping the Planet

• Uncontrolled "experiment on a planetary scale for
  which the outcome is uncertain.
• The world has become increasingly humanized, and
  ecosystems have become more fragmented and
  diminished in aggregate size.
• Consequently, ecosystems are loosing resilience
  and thus need greater protection from threats to
  their integrity.
• In her 4 billion years of environmental changes,
  human species has altered the planet for only 4
  million years
• However, the rate and intensity of change that
  occurred in the last century are a cause for deep
  concern.

68
Human Activities Reshaping the Planet

• We can say that
• Ecotoxicology is an attempt to provide some rules
  for the planetary game human society is playing.
• Since sport has rules that are discussed in great
  detail by fans.
• The human, needs to recognize the natural laws
  that determine the outcome of the game of life in
  which all are participants.

69
Functioning Planet Despite Uncertainty

• Human condition and the "tools of the trade"
  (ecotoxicology) are constantly changing.
• Theories and practices once thought to be
  sufficient have been shown to be inadequate,
  often with stunning rapidity.
• Ecotoxicology can make major contributions in
  reducing the frequency and intensity of
  environmental surprises by
• determining critical ecological thresholds and
  breakpoints,
• developing ecological monitoring systems to
  verify that previously established quality
  control conditions are being met,
• establishing protocols for the protection and
  accumulation of natural capital,
• providing guidelines for implementing the
  precautionary principle,
• developing guidelines for anthropogenic wastes
  that contribute to ecosystem health, and
• responding to environmental changes with prompt
  remedial ecological restoration measures when
  evidence indicates that an important threshold
  has been crossed.

70
Natural Capital

• Natural capital consists of
• Resource, Living Systems and Ecosystem Services.
• Natural capitalism envisions the use of natural
  systems without abusing them
• Sustainable use of the planet
• requires a mutualistic relationship between human
  society and natural systems
• affirms that a close relationship exists between
  ecosystem health and human health.
• Hence Natural capitalism deals with the critical
  relationship between
• natural capital -- natural resources,
• living systems, and the ecosystem services they
  provide --human-made capital

71
Industrial Ecology

• Industrial ecology is the study of the law of
  materials and energy in the industrial
  environment and the effects of these flows on
  natural systems
• The essential idea of industrial ecology is the
  coexistence of industries and natural ecosystems.
  
• Properly managed, industrial ecology would
  enhance the protection and accumulation of
  natural capital in areas now ecologically
  degraded or at greater risk than necessary.
• The most attractive feature of industrial ecology
  may be that it would involve temporal and spatial
  scales greater than those possible with even the
  most elaborate microcosms or mesocosms.

72
Natural Capital and Industrial Ecology

• Ecotoxicologists must be knowledgeable of the
  practices commonly used in ecological restoration
  since Ecological damage is inevitable
• Industrial accidents if immediately studied by
  qualified personnel and the information widely
  shared can even be a valuable source of
  ecotoxicological information
• Regulatory and industrial flexibility in
  assessing experimental remedial measures would
  also enhance the quality of the information base.

73
Speculations

• Ecotoxicologists have a responsibility to raise
  public literacy about their field so that the
  information they generate is taken seriously and
  utilized effectively.
• Ecotoxicologists and other environmental
  professionals must be aware that their data,
  predictions, estimates, and knowledge will be
  used in a societal context that is embedded in an
  environmental ethics
• Sustainable use of the planet will require a
  major shift in present human values and practices.

74
Speculations

• A multidimensional research strategy is needed
  that emphasizes for e.g.
• ecosystem complexity,
• dynamics.
• resilience, and
• Interconnectedness
• However major obstacles exist to the development
  of such a program in the educational system,
  governmental agencies, industry, and with a
  citizenry increasingly suspicious of science and
  academia in general.

75
Speculations

• Society depends primarily on its major
  universities for the generation of new knowledge
  but this function has become a commodity produced
  for sale, which means the research direction is
  all too often a function of marketability.
• Ecotoxicologists may often postpone visionary,
  long-term projects whose outcomes are highly
  uncertain for short-term projects of severely
  limited scope determined by the perceived needs
  of the funding organization rather than being
  truly exploratory undertakings.

76
Speculations

• Some counter trends exist to these discouraging
  developments, often occurring outside of
  "mainstream science e.g.
• A number of new journals are challenging the
  fragmentation of knowledge, and publications are
  espousing the leaping together of knowledge.
• Environmental professionals, such as
  ecotoxicologists, are finding ways to minimize
  the effects of budgetary constraints.
• Ironically, to persuade decision makers that a
  major shift in approach is needed to cope more
  effectively with the ecotoxicological and other
  uncertainties that human society now faces and
  are likely to increase substantially in the
  future, one or more major environmental
  catastrophes will be needed.