Environmental Pollution: A Major Threat

Pollution is any, physical, chemical or biological changes that adversely affect the health, survival or activities of living organisms that alter the environment in an undesirable way.
Sources of Pollution

Sources of Pollution are of two types:

• Natural Sources
• Man made Sources

Natural Sources of Pollution:
Natural sources of pollution includes volcanic activity, algal blooms, dramatic changes in the ocean currents.
Volcanic activity can lead to alteration of climatic conditions. algal blooms can cause low level of Biological oxygen demand there by killing fishes. changes in the Ocean current can lead to poor nutrient cycling.

Man made sources
All human activities.
agricultural impact on environment.
Transportation of Hazardous materials
Incineration of waste products.
Industrial activities.
Pollutants are released accidentally, some times deliberately in a single step or continuously eg: effluents.leak or leaching of water.

Environmental Pollutants
Biological - Cholerae Bacterium, sewage pollution of water
Physical - Heat, Noise, Radioactivity, Particulate matter.
Chemical - chemicals are intrinsically harmful, eg: heavy metals, Xenobiotic compounds.
Most naturally occurring substances ie, pollutants whose increased concentration in environment can lead to health problems or environmental damage. Eg: chloride in water.
Priority Pollutants
US environmental protection agency has listed 129 priority pollutants which are dangerous and can cause health problems and environmental damage.

Persistent Organic Pollutants (POP's)
12 most notorious persistent organic pollutants (POPs) are called as dirty dozens: these are
1. DDT
2. Toxaphane
3. PCB's
4. Dioxins & Furans
5. Hexachloro Benzene
6. Chlordane
7. Dieldrin
8. Endrin
9. Aldrin
10. Mirex
11.Heptachlor