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 or

b) Anthropogenic sources

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 pollutantI- According to nature of the pollutantA- 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 environmentsA) 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)