Chapter 2 Pollution A Threat To Biodiversity Air Pollution

Pollution:

The introduction of harmful particles into environment which causes the Harmful or poisonous effect to our environment is called pollution.

These harmful particles which cause poisonous effects are called pollutants. Nowadays pollution has reached its peak that causes adverse change and human illness,

Air Pollution

Primary pollutants:

The pollutants that are released directly from the source i.e. CO, SO, etc., -

 Secondary pollutants:

The pollutants that are released indirectly from the source. When primary pollutants react in atmosphere with other substances to form secondary pollutants i.e. Ozone, nitrogen dioxide, acid rain etc. . . . 

 Types of pollution

Following are the major five types of pollution.

        i.            Air pollution

      ii.            Soil pollution

    iii.            Water pollution

     iv.            Noise pollution

       v.            Radioactive pollution

Air pollution

When pollutants are present in air, this is called air pollution. It is the most dangerous form of pollution for life.

Types of air pollutants:

; a) Sulphur dioxide

Sources burning of fossil fuels such as coal oil and gas release sulphur dioxide and nitrogen, oxides in atmosphere.

Effects

·         Damages plants and animals.

• ·         So2 penetrates into leaves through stomata causing damage to leaves and kills the plants.
• ·         In North America, from smelting work, SO2 releases that completely destroy the . vegetation.
• ·         In human, it damage lining of eyes, air passage and lungs.
• ·         Prolong exposure to SO2 causes respiratory diseases.

b) Lead Sources

Lead may be present in air, water and food. Some fossils fuels such as petrol also release Pb on burning. It is used as anti-knocking agent. Paints, toys, cosmetics and folk, medicines are sources of lead. It is also produced by fission of radioactive substances

Effects

Anemia, cramp, loss of muscles control, coma, kidney and brain damage in human, death and forest decline are some effects of lead compound’

¢) Carbon dioxide Sources

·         Burning of organic compounds in industries and automobiles

·         Respiration process.

Effects

• ·         Causes greenhouse effect.
• ·         Causes global warming.
• ·         Causes in melting of ice.
• ·         Rises sea level water and causes flooding.

d) Carbon monoxide

Sources

Incomplete burning of carbonates and carbon compounds release carbon monoxide

Effects

·  Carbon monoxide combines with hemoglobin to form carboxy hemoglobin.

·                    The hidden enemy reduces the blood ‘capacity to transport oxygen. It also damages brain and causes headaches and death.

e) Chlorofluorocarbons Sources

Aerosol spray, foam packing, air conditioning system and refrigerators.

Effects

• ·         Breakdown of ozone layer
• ·         Allows ultraviolet radiation to penetrate to earth
• ·         ‘Increasing risk of cancer
• ·         Cataracts in humans
• ·         Distorts weather pattern
• ·         Destroys plants, animals and planktons.