TYPES OF AIR POLLUTANTS AND THEIR EFFECTS

TYPES OF AIR POLLUTANTS

Primary pollutants are those pollutants that are emitted from known sources.

These are for example:

• SO2
• CO2
• NO
• SOx
• Particulates
• Hydrocarbons
• Metals

Secondary pollutants are those pollutants that are formed through chemical reactions in the atmosphere. 

Examples are:

• O3
• PAN
• Oxidized Hydrocarbons

The pollutants described by USA, EPA and EC are:

• CO
• NO2
• O3
• SO2
• PM-10
• Lead

EFFECTS OF POLLUTANTS

1) HUMAN HEALTH

Health effects are given the major consideration while studying the effects of pollutants. The respiratory system of humans is efficient enough for filtering the large particles in air while breathing. The particles that are smaller than 5 µm penetrate in lungs and make deposits in alveoli. For Instance, cigrette smoke particles size is smaller than 1 µm and they are deposited in the alveoli. Some particles are more damaging because of their capability of absorbing gases. Both gases and materials enhance their effect of damage and they enter in deeper lung pockets and affect gastrointestinal system. Lead like chemicals enter in bloodstream via respirator system or by passing through lung membranes. Tritium like substances enter in bloodstream through skin. 

2) EFFECTS ON PLANTS AND ANIMALS

Not only humans but plants and animals are also affected by pollutants. Fluorine for instance is released from fertilizer,, phosphate, aluminium glass and clay baking operations. Fluorine damages the flowers and fruits. It affects the plants at great degree of magnitude. Even at lower concentrations fluorine affects shrubs, tree and grass which are eaten by cattle or other animals. In animals fluorosis can also be occurred. Poor animal health and their low survival is happened. Other heavy metals like mercury and lead also damage the plants and animals. 

Some plants and animals have the susceptibilities to pollutants.Just like angiosperm phylogeny group can tolerate the high concentration of sulphur dioxide alone but if sulphr dioxide and ozone both are exposed than it can not tolerate.

3) EFFECTS ON MATERIALS

Sulphur and Nitrogen oxides reaction in atmosphere made acidic compounds that attacks the metal surfaces. Fluorine is highly reactive and it causes etching of glass at high concentrations. Hydrogen Sulphide in ambient air reacts with lead oxide in white paint and form the lead sulphide that causes white houses to be turned into brownish tint overnight.

The Shish Mahal at Lahore Fort, Shalimar Gardens, Jahangir Tomb and Data Darbar are badly affected by air pollution.