UNIT-IV Environmental Pollution &
Control
The introduction of different harmful pollutants into certain environment that makes this
environment unhealthy to live in.
The most common pollutants are usually chemicals, garbage and waste water.
Environmental pollution is happening in many parts of the world, especially in form of air and water
pollution.
The best example for air pollution is some of China’s cities, including Beijing, and the best example
for water pollution is India with its Ganga river pollution problem.
1) AIR POLLUTION
Air pollution occur due to the presence of undesirable solid or gaseous particles in the air in
quantities that are harmful to human health and the environment.
The major pollutants which contribute to outdoor air pollution are sulphur dioxide, carbon dioxide,
carbon monoxide, nitrogen oxides, ozone. Total suspended matter, lead, carbon dioxide, and toxic
pollutants.
The sources of air pollution can be grouped as under:
(i) Natural; such as forest fires, ash from smoking volcanoes, dust storm and decay of
organic matters.
(ii) Man made; such as population explosion, deforestation, urbanization and
industrializations.
EFFECTS OF AIR POLLUTION
Human respiratory system has several mechanisms for protection from air pollution. Bigger particles
(>10 um) can be trapped by the hairs and sticky mucus in the lining of the nose.
Smaller particles can reach tracheobronchial system and there get trapped in mucus. Hey are sent
back to throat by beating of hair like cilia from where they can be removed by spitting or swallowing
Year of exposure to air pollutants (including cigarette smoke) adversely affect these natural
defenses and can result in lung cancer, asthma, chronic bronchitis and emphysema (damage to air
sacs leading to loss of lung elasticity and acute shortness of respiration).
Air pollutants affect plants by entering through stomata (leaf pores though which gases diffuse),
destroy chlorophyll and affect photosynthesis.
CONTROL OF AIR POLLUTION
Public Transport.
Electric Vehicles.
Planting More Trees.
Using Non-Conventional Sources of Energy.
Using Low Sulphur Coal-in-Industries.
, Removing Sulphur From Coal (By Washing or with Help of Bacteria)
2) WATER POLLUTION
When toxic substances enter lakes, streams, rivers, oceans and other water bodies, they get
dissolved or lie suspended in water or get deposited on the bed. This results in the pollution of
water.
SURFACE WATER POLLUTION: THE MAJOR SOURCES OF SURFACE WATER
POLLUTION ARE:
1. Sewage: Pouring the drains and sewers in fresh water bodies causes water pollution. The
problem is severe in cities.
2. Industrial effluents: Industrial wastes containing toxic chemical, acids, metallic salts,
phenols, cyanides, ammonia, radioactive substance, etc are sources of water pollution. They
also cause thermal (heat) pollution of water.
3. Synthetic detergents: Synthetic detergents used in washing and cleaning produce foam and
pollute water.
4. Agrochemicals: Agrochemicals like fertilizers (containing nitrates and phosphates) and
pesticides (insecticides, fungicides, herbicides etc). washed by rain-water and surface run-off
pollute water.
5. Oil: Oil spoilage into sea-water during drilling and shipment pollute it.
6. Waste heat: Waste heat from industrial discharges increase the temperature of water
bodies and affects distribution and survival of sensitive species.
EFFECTS OF WATER POLLUTION
Increased incidence of Tumours, Ulcers due to Nitrate Pollution.
Increased incidence of Skin Disorders due to Contact with Pollutants.
Increased incidence of Constipation, Diarrhoea and Infections to Intestine.
Imbalances created in Secondary Food Chains.
Large scale death of Aquatic and Terrestrial Animals .
CAUSES OF WATER POLLUTION
Judicious use of Agrochemicals like Pesticides and Fertilizers.
Separate drainage of Sewage and Rain Water should be provided.
Planting trees would reduce pollution and will also prevent soil erosion.
Waste waters should be properly treated.
3) SOIL POLLUTION
Soil is the upper layer of the earth crust which is formed by weathering of rocks.
Organic matter in the soil makes it suitable for living organisms.
Dumping of various types of materials especially domestic and industrial wastes causes soil
pollution.
Domestic wastes include garbage, rubbish material like glass, plastic, metallic cans, paper, fibres,
cloth rags, containers, paints, varnishers, etc.
Control
The introduction of different harmful pollutants into certain environment that makes this
environment unhealthy to live in.
The most common pollutants are usually chemicals, garbage and waste water.
Environmental pollution is happening in many parts of the world, especially in form of air and water
pollution.
The best example for air pollution is some of China’s cities, including Beijing, and the best example
for water pollution is India with its Ganga river pollution problem.
1) AIR POLLUTION
Air pollution occur due to the presence of undesirable solid or gaseous particles in the air in
quantities that are harmful to human health and the environment.
The major pollutants which contribute to outdoor air pollution are sulphur dioxide, carbon dioxide,
carbon monoxide, nitrogen oxides, ozone. Total suspended matter, lead, carbon dioxide, and toxic
pollutants.
The sources of air pollution can be grouped as under:
(i) Natural; such as forest fires, ash from smoking volcanoes, dust storm and decay of
organic matters.
(ii) Man made; such as population explosion, deforestation, urbanization and
industrializations.
EFFECTS OF AIR POLLUTION
Human respiratory system has several mechanisms for protection from air pollution. Bigger particles
(>10 um) can be trapped by the hairs and sticky mucus in the lining of the nose.
Smaller particles can reach tracheobronchial system and there get trapped in mucus. Hey are sent
back to throat by beating of hair like cilia from where they can be removed by spitting or swallowing
Year of exposure to air pollutants (including cigarette smoke) adversely affect these natural
defenses and can result in lung cancer, asthma, chronic bronchitis and emphysema (damage to air
sacs leading to loss of lung elasticity and acute shortness of respiration).
Air pollutants affect plants by entering through stomata (leaf pores though which gases diffuse),
destroy chlorophyll and affect photosynthesis.
CONTROL OF AIR POLLUTION
Public Transport.
Electric Vehicles.
Planting More Trees.
Using Non-Conventional Sources of Energy.
Using Low Sulphur Coal-in-Industries.
, Removing Sulphur From Coal (By Washing or with Help of Bacteria)
2) WATER POLLUTION
When toxic substances enter lakes, streams, rivers, oceans and other water bodies, they get
dissolved or lie suspended in water or get deposited on the bed. This results in the pollution of
water.
SURFACE WATER POLLUTION: THE MAJOR SOURCES OF SURFACE WATER
POLLUTION ARE:
1. Sewage: Pouring the drains and sewers in fresh water bodies causes water pollution. The
problem is severe in cities.
2. Industrial effluents: Industrial wastes containing toxic chemical, acids, metallic salts,
phenols, cyanides, ammonia, radioactive substance, etc are sources of water pollution. They
also cause thermal (heat) pollution of water.
3. Synthetic detergents: Synthetic detergents used in washing and cleaning produce foam and
pollute water.
4. Agrochemicals: Agrochemicals like fertilizers (containing nitrates and phosphates) and
pesticides (insecticides, fungicides, herbicides etc). washed by rain-water and surface run-off
pollute water.
5. Oil: Oil spoilage into sea-water during drilling and shipment pollute it.
6. Waste heat: Waste heat from industrial discharges increase the temperature of water
bodies and affects distribution and survival of sensitive species.
EFFECTS OF WATER POLLUTION
Increased incidence of Tumours, Ulcers due to Nitrate Pollution.
Increased incidence of Skin Disorders due to Contact with Pollutants.
Increased incidence of Constipation, Diarrhoea and Infections to Intestine.
Imbalances created in Secondary Food Chains.
Large scale death of Aquatic and Terrestrial Animals .
CAUSES OF WATER POLLUTION
Judicious use of Agrochemicals like Pesticides and Fertilizers.
Separate drainage of Sewage and Rain Water should be provided.
Planting trees would reduce pollution and will also prevent soil erosion.
Waste waters should be properly treated.
3) SOIL POLLUTION
Soil is the upper layer of the earth crust which is formed by weathering of rocks.
Organic matter in the soil makes it suitable for living organisms.
Dumping of various types of materials especially domestic and industrial wastes causes soil
pollution.
Domestic wastes include garbage, rubbish material like glass, plastic, metallic cans, paper, fibres,
cloth rags, containers, paints, varnishers, etc.
