Ecotoxicology is the study of the effects of toxic chemicals on biological organisms, especially at the population, community, ecosystem, and biosphere levels.

1. Ecotoxicology
by Dr. Eman Ezz
Elsharkawy Assiut

2. ENVIRONMENTAL
TOXICOLOGY
Dr.
Eman
Elssharka
wy

3. THE ENVIRONMENT
It is the surrounding medium in
which the animal affects and effect
on it.
* Macro-environment
* Micro-environment

4. ENVIRONMENTAL POLLUTION
Means increase in the percentage
of one or more element of
environmental constituent than
normal or presence of foreign body
in the environment leading to
damage or destruction of the
biological system.

5. ENVIRONMENTAL
TOXICOLOGY
Definition
“ Environmental toxicology”: refers
to study of the direct effects of
environmental chemicals on human
beings specifically, whereas
"Ecotoxicology" refer their effects on
other species and ecosystem.

6. ECOTOXICOLOGY
It is concerned with the
harmful effects of chemicals
upon ecosystems. That include
the chronic effects of
anthropogenic chemicals,
chemical mixtures, and natural
substrates on organisms,
structures within ecosystems.
Also on diversity of organisms,
populations, and communities.

7. ANTHROPOGENIC
Anthropogenic effects,
processes or materials are
those that are derived from
human activities, as opposed to
those occurring in natural
environments without human
influence.

8. XENOBIOTIC
• A chemical that is foreign to the
biosphere i.e. is not produced by a
natural biological or a biotic source.
• Also called anthropogenic, man-
made, synthetic, pollutant,
contaminant, recalcitrant, persistent,
and toxicant.

9. ECOSYSTEMS
It is the space where all the
microorganisms, plants, animals, and
humans live.
It includes the air close to the ground, the
soil where the roots of plants are present,
caves, and all surface- water systems,
including depths of oceans.
Ecosystems are part of the biosphere and
are connected to each other by immense
transfers of mass and substrates.

10. The biosphere is
divided into aquatic,
terrestrial systems
and air in the lower
part of the
atmosphere, in
which flying animals
are prevalent and
where substrates are
transferred by the
wind.
Simple
ecosystem
model

11. Environmental toxicology depends on
 Lab work
 Effects of toxicants on biochemistry and physiology.
 Field work
 Field observations of reproduction and survival in
polluted vs. non-polluted sites.
 Modeling of fate and transport of toxicants in the
environment i.e. exposure and risk assessment
 Static models : short term modeling of
ecosystems
 Strategic models : model of a specific aspect of a
system
 Testable models : model makes predictions that can
be tested in the field or laboratory

12. Purpose/function of environmental toxicology is to
 Identify the mode / site of action of a xenobiotic.
 FATE and TRANSPORT / interaction of a xenobiotic with the
biosphere (including specific organisms) after it is released
/ pollution occurs.
 Identify the effect the xenoboitic has on an ecosystems /
higher level organisation e.g. loss of fertility of Alligators in
Lake Apopca.
Introduction of
xenobiotic
Ecosystem
effect
site of
action
biotransformation
physiology
behavior
community
parameters
biochemistry population
dynamics

13. Introductio
n of
xenobiotic
Ecosystem
effect
DNA
RNA
Receptors
Key enzymes
Biochemical integrity
enzyme induction
Glutathione S Transferase
Mixed Functional Oxidases
Hydrolases
DNA repair mechanisms
Physiology, Behavior
Chromosome damage
Lesions, Necrosis
Tumors
Teratogenic effects
Behavior, Mortality
Community
structure
Diversity
Energy transfer
Stability
Succession
Chemical
parameters
Stress proteins
Metabolic indicators
Acetylcholinesterase inhibition
Adenyl energy charge
Metallothionen production
Immuno suppression
Population density
Productivity
Mating success
Fecundity
Genetic alterations
Competitive alterations
Parameters of xenobiotic interaction with the
ecosystem

14. POLLUTION OF ECOSYSTEMS
Sources of ecosystem pollution
It is usually arises from either:
a) Natural sources or
b) Anthropogenic sources

15. A) NATURAL SOURCES
These sources include:
Metallic ions
Mycotoxins
Soil nutrients
Volcanic activities

16. B) ANTHROPOGENIC
SOURCES
They include:
 Industry and agriculture activities.
 Botany (alteration of plants by breeding,
selection, and genetic engineering).
 Mining, deforestation, transportation and
construction.
 Habitations (waste products, sewage, and
debris).
 Military activities (radiation, chemical
warfare agents).

17. Classification of the
pollutantI- According to nature of the pollutant
A- Chemical
Inorganic ---- Heavy metals
Organic ---- Cyclic hydrocarbon (propane,
hexane)
Others ---- Fertilizers, pesticides
B- Physical
Electrical, thermal ionizing radiation
C- Biological
Bacteria, virus, parasites, toxins, animal & human
wastes, animal byproduct & decayed &

18. II- According to the environments
A) Air pollutants (Co2, Temp, So2, Lead)
B) Soil pollutants (Fertilizers, pesticides, heavy
metals)
C) Water pollutants (heavy metals,
microorganisms)
III- According to the source
1) Agriculture pollutants
2) Industrial pollutants
3) Military pollutants
4) Natural pollutants (Dust, pollen)

19. According to mode of action (Receptors)
 Chemicals that interfere with biochemical receptor
sites
 Signaling
 proteins in membranes
 Replication
 Protein synthesis
 Chemicals that damage biochemical or molecular
targets
 DNA damage
 Strange breakage
 Chromosome abnormalities
 Cancer
 Non-genotoxic effects such as immunosuppression

20. Physiological and behavioral effects
 Standard tool for assessing toxicological effects on
populations
 Tissue lesions
 Tumors
 Reproductive success
Population success
 Population age structure – xenobiotics often
exert a stronger effect on juveniles => a shift in
age structure might indicate that a population is
not doing well, because it is affected by a
xenobiotic.
 Shift in bacterial communities – contamination
reduces bacterial diversity; bacterial numbers
often increase because the contaminant is food
for some while it is toxic for others.

21. METALS
Hg, Cd, Zn, Pb
PESTICIDES
Insecticides
Organochlorines (DDT, Lindan,
Dieldrin)
Organophosphates (Dimethoat,
Diazinon)
Carbamates (Methiocarb,
Carbofuran)
Pyrethroides (Deltamethrin,
Cypermethrin)
Rodenticides (Warfarin)
Herbicides (“Agent orange”, diquat,
paraquat, dinitrophenoles)
Fungicides (Metylbromid, Dazomet,
Borax)
POLYCHLORINATED BIPHENYLES (PCB)
POLYKLOREREDE DIBENZODIOXINER
(PCDD)
By-products of burning PCBs and
pesticide manufacturing
OIL PRODUCTS
Polyaromatic hydrocarbons (PAHs) -
naphtalene, benzo(a)pyrene
ENDOCRINE DISRUPTORS
Alkylphenolpolyethoxylates, Bisfenol A,
DDE, PCB, farmaceutikals, 17α-
ethinylestradiol
CHLORIDE PHENOLS
Polychlorinated phenols (wood
preservatives, bleaching agents)
TRIBUTYLTIN
Ship paints
DETERGENTS
Washing powder
Important xenobiotics