Environmental
Toxicology
The environment
• It is the surrounding medium in which the
animal affects and effect on it.
• * Macro-environment
• * Micro-environment
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.
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.
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.
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.
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.
• 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
Pollution of ecosystems
• Sources of ecosystem pollution
It is usually arises from either:
a) Natural sources
b) Anthropogenic sources
or
a) Natural sources
These sources include:
•
•
•
•
Metallic ions
Mycotoxins
Soil nutrients
Volcanic activities
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).
Classification of the pollutant
I- 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 & poisonous plant
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)