types of environmental pollution
Pollution and its impact on life
Surely you would have heard about changes taking place in the environment. Daily we read in the newspapers, see on television and listen on radio about the increasing levels of dust and smoke in the cities. People complain that noise due to traffic is becoming unbearable. Heaps of rubbish are a common scene in streets or on roads and municipal committees have failed to manage solid wastes. You might have also heard that excessive and unwise use to chemical fertilizers has become a common practice. Soil is subjected to erosion. The temperature of the earth is increasing which may lead to rise in sea levels. All these examples are different aspects of pollution and its consequences. Have you ever thought why this all happening is? Actually wastes and surplus materials generated due to human activities enter into the environment (air, water and soil) and cause unfavorable changes in it and pose threat to plant, animal and human life.
Materials causing pollution are called “pollutants”. Some important pollutants are carbon dioxide, carbon monoxide, sulphur dioxide, DDT, dust, noise, and disease casing germs.
Types of pollution
According to the part of the environment being affected, pollution can be divided into the following types:
- Water pollution
- Air pollution
- Land pollution
About three fourth of earth’s surface is covered with water. However, you might be surprised to know that only one percent of this water is available for our use. This fresh water is present in lakes, springs, rivers, streams and underground reservoirs. It is a pity that we are not only using this little amount of water wastefully but are also badly polluting it.
Causes of water pollution
Some major causes of water pollution are:
- Industrial affluent, which is discharged, untreated into watercourses.
- Sewerage, which includes domestic garbage, human and animal excreta, detergents and sludge.
- Insecticides and other chemical sprays, which are washed away from crops and carried into water bodies with rainwater.
- There are some areas in our country where people still use water collected in open pools. Farm animals, birds and other wild animals also use the same water and pollute it in many ways.
- Oil seeping, out of tankers, is a major source of pollution of seas and oceans.
- Clay, sand and minerals produced by erosion of soil enter into rivers, streams and lakes.
- Sulphur dioxide, in the polluted air, gets dissolved in rain water and comes down as acid rain. This acid rain is another cause of water pollution.
Effects of water pollution on Plant, Animal and Human Life
- Germs present in the polluted water cause a number of diseases such as cholera, dysentery, diarrhea, typhoid and worms of alimentary canal. Particularly, children become victims to these diseases. If possible water should be boiled before drinking.
- Aquatic life (plants and animals) is badly affected by the insecticide and other chemicals in industrial affluent. When these chemicals get into the human bodies, they cause diseases.
- Affluent from paper mills, food factories and domestic sewer depletes dissolved oxygen, thus endangering aquatic life.
- Oil splits threaten sea animals.
Causes and Effects
Burning of fuel and litter in homes and factories and traffic produces smoke and poisonous gases that enter into the atmosphere. These poisonous gases and harmful particles enter into the human body with inspired air and through skin. They may cause cancer, allergy and diseases of throat, lungs, skin and eyes. They are not only harmful to our health but are injurious to plants as well.
Causes and Effects
Domestic trash and other solid wastes are thrown into the streets or are dumped at open places. These sites serve as breeding and feeling places for rats, flies, worms and germs, which spread diseases.
Water from factories, containing chemicals (lead, chromium, mercury etc.), sludge from sewers and hospital wastes are major pollutants of land. In addition to these agricultural wastes such as chemical fertilizers and insecticides (DDT) also cause land pollution. Chemicals from land get their way into the plant and animal bodies and from there into human bodies and may cause diseases.