Following measures can be adopted to protect and improve environment:

1. Plant more and more trees.
2. Start recycling of domestic and agricultural waste to produce manure and biogas.
3. Separate the biodegradable wastes from non-biodegradable wastes before disposing them.
4. Avoid unnecessary use of fuels.
5. Use renewable sources of energy such as solar energy, wind energy, ocean thermal energy, water energy.
6. Use unleaded petrol in vehicles.
7. Never throw chemicals and oils in drains and toilets.
8. Avoid use of polythene bags.
9. Don’t burn any article made up of plastic, rubber or polythene because their smoke contain harmful gases.

Environmental laws
Many environmental laws are being enacted by state and centre governments to conserve environment and keep it pollution free. Following is the list of some important environmental laws enacted by government of India:

1. Prevention of Cruelty to Animals Act, 1960.
2. Air (Prevention and Control of Pollution) Act, 1981.
3. Water (Prevention and Control of Pollution) Act, 1974.
4. Wildlife (Protection) Act, 1972.
5. Environment (Protection) Act, 1986.
6. Forest (Conservation) Act, 1980.
7. The Factories Act, 1948.

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 In our country a large number of national parks and wildlife sanctuaries have been established by government to conserve and protect wildlife. A national park is an area which is established by law to conserve wildlife. Whereas, a sanctuary is an area where killing or capturing of any species of wild animal is prohibited by law. About 83 national parks and 447 wildlife sanctuaries have been established in India by government to conserve and protect wildlife. Out of these, the name and location of some important national parks and sanctuaries are:

1. Kaziranga National Park (Assam)
2. Nandankanan Biological Park (Bhubaneshwar)
3. Kanha (Madhya Pradesh)
4. Desert National Park (Thar)
5. Gir Sanctuary (Gujarat)
6. Corbett National Park (Uttranchal)
7. Bharatpur Bird Sanctuary (Rajasthan)

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In 1948, the International Union for Conservation of Nature and Natural Resources (IUCN) was set up. The main task of IUCN is conservation of wildlife and implementation of various environmental laws. The IUCN has made following categories of wild animals and plants:

1) Extinct Species

Extinct species are those species whose last organism has died i.e. which have disappeared from earth. Examples of extinct species are pink headed duck, mountain quail, lesser one horned rhino etc.

2) Endangered Species

Endangered species are those species which are in danger of extinction. For example, Indian rhinoceros, Asiatic lion, crocodile, musk deer, blue whale etc. are endangered species.

3) Vulnerable Species

Those species which have sufficient population at present but can become endangered species in future if unfavourable conditions persist in its environment. The main examples of vulnerable species are golden cat, Indian egg eating snake, olive ridley turtle etc.

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The term conservation means to keep safe. So, conservation of environment means to prevent the excessive use of natural resources so as to keep the environment safe. Environment can be conserved by adopting various practices. These are:

1. Planting new trees in place of those cut for various purposes.
2. Controlled use of fertilizers, insecticides and weedicides in fields.
3. Rotation of crops.
4. Recycling of organic waste to prepare biogas and manure.
5. Chemical treatment of domestic sewage, so that it does not pollute water bodies like rivers and lakes.
6. Harvesting rain water to conserve ground water.
7. Setting up of national parks and wildlife sanctuaries to protect wild animals.

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Environment and Population
Population of human beings is increasing at alarming rate. Increase in population is causing many environmental problems. To fulfill the basic needs of food, clothing and shelter human beings are exploiting forests, mountains, sea and rivers. All of us know that we have very limited natural resources. So, the ever increasing demands of population cannot be fulfilled by these limited natural resources. If this trend of population increase is not checked immediately, it will disturb the balance in nature and bring disaster.

 So, the only way to improve the environment is to maintain the population of human beings within a certain limit.

Environment and Sustainable Development
In the past, human beings used to live in nature by utilizing minimum natural resources to fulfill their needs. But, with the passage of time science and technology developed. This resulted in rapid use of natural resources and degradation of environment. In this age of development small villages and town have been developed into big cities.

Agricultural lands have been used for construction of industries and hotels. Forests and mountains have been exploited for timber and fuel. Dams have been constructed on rivers to produce electricity. In this way development took place at very high rate, but at the same time it has adversely effected the environment.

So, in order to maintain the balance in nature and to reduce the harmful effects of development on environment it is necessary to keep the development at such a pace that it does not cause any kind of damage to the environment. Such a development which does not cause any kind of damage to the environment is called sustainable development. For this, we will have to plant more trees and live in harmony with nature. Green grassy patches will have to be grown in buildings. And we will have to adopt those technologies which are environment friendly and based on recycling and proper use of natural resources.

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Radioactive pollution is caused by high energy invisible radioactive radiations which are emitted by radioactive substances.

Radioactivity

Radioactivity is that property of certain unstable elements to emit alpha particles, beta particles and gamma rays by undergoing spontaneous disintegration of their atomic nuclei. Radioactive substances are those unstable substances which emit invisible radioactive radiations (such as alpha particles, beta particles and gamma rays) by undergoing spontaneous disintegration of their atomic nuclei. Radioactive pollution is very harmful for all organisms.

Sources of Radioactive Pollution

Sources of radioactive pollution can be divided into two types. These are:

1. Natural sources of radioactive pollution
2. Man-made sources of radioactive pollution

1. Natural Sources of Radioactive Pollution
These sources involve naturally occurring radioactive elements such as radium, thorium, plutonium, uranium 235, potassium 40 and carbon 14 etc.

2. Man-made Sources of Radioactive Pollution
These sources involve mining and refining of radioactive elements, production and explosion of nuclear weapons, nuclear power plants, improper disposal of nuclear wastes and preparation of radioactive isotopes.

Effects of Radioactive Pollution
Radioactive pollution can cause various health related problems in human beings. These radiations can cause loss of hair, tumors, skin cancer, leukemia, disturbance in metabolic activities of body, change in chromosome makeup and mutations.

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Noise pollution may be defined as the disturbance produced in our environment by undesirable loud sounds of various kinds. Noise pollution adversely affects our physical and mental health.

Sources of Noise Pollution

Following are the main sources of noise pollution:

1. Noise pollution is caused by various devices and electric appliances used in our homes such as desert coolers, air-conditioners, vacuum cleaners, pressure cooker, mixer and grinder etc.
2. Noise pollution is caused by various sources of entertainments such as television, radios, cd players, stereos etc.
3. Transport vehicles like scooters, motor-cycles, cars, buses, trucks, trains and aeroplanes cause noise pollution.
4. Noise pollution is also produced by machinery used in factories.
5. Loudspeakers, crackers and dynamite blasting are also main source of noise pollution.

Effects of Noise Pollution
 Noise pollution affects general health and hearing of human beings.

Effects of Noise Pollution on General Health

1. Noise pollution causes headache, eye strain and digestive problems in a normal human being.
2. Noise pollution causes anxiety and stress in human beings.
3. Noise pollution also increases the rate of heart beat, high blood pressure and heart related problems.
4. Noise pollution can also cause problems in night and colour vision.

Effects of Noise Pollution on Hearing

1. Noise pollution may reduce the hearing capacity of a person.
2. Noise pollution interferes in communication with others.

Prevention and Control of Noise Pollution
 Noise pollution can be prevented by following methods:

1. The factories should be established out of cities and town.
2. Use of pressure horn in cities should be prohibited.
3. The machines used in factories and industries should be lubricated from time to time to reduce sound produced by them.
4. Use of loudspeakers and amplifiers should be banned.
5. Better engines should be used in vehicles to reduce sound.
6. Entertainment devices such as television, radio, stereo, cd players should be played on low volume.

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 Soil erosion is the removal of top fertile soil by various physical agencies such as water and air. Thus, soil erosion is caused mainly by water and air. Soil erosion occurs mainly in those areas where the top soil is not covered by vegetation. Due to soil erosion fertility of soil reduces.

Cause of Soil Erosion

The various causes of soil erosion are:

1. Heavy Rainfall
The flow of water during heavy rainfalls removes the top soil of land and cause soil erosion.

2. High Speed Winds
The top soil of land is also removed by the high speed winds. So, winds also cause soil erosion.

3. Overgrazing
Intensive grazing of vegetation by animals on the outskirts of villages and forests remove the protective vegetation cover of the soil. Thus, overgrazing helps in increasing soil erosion.

4. Slopes
Slopes decrease the capacity of soil to absorb water and increase the speed of run-off. As water moves along slopes, it gathers high speed and cause large scale soil erosion by cutting and carrying away particles of soil.

5. Human Interference
Large scale cutting of forest trees by human beings for timber and fuel exposes the soil to the direct effects of water and air. Thus, it causes soil erosion.

Prevention of Soil Erosion

We can prevent soil erosion by following methods:

1. Reforestation and plantation of grass can prevent soil erosion.
2. By controlling grazing of vegetation by animals, soil erosion can be prevented.
3. Agricultural practices such as crop rotation, mixed cropping and field fallowing improve soil fertility and thus decrease soil erosion.
4. Soil erosion can be prevented by growing trees in a row. These are called wind breaks.
5. Soil erosion can be prevented by controlling the flow of water by constructing dams on rivers and lakes.
6. In hilly areas soil erosion can be prevented by adopting the technique of step farming.

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 We have already discussed that domestic and industrial wastes are the main source of pollution. So, various methods are developed by scientists to get rid of these wastes. Some of important methods for disposal of wastes are:

1. Recycling
Recycling is the process of converting wastes into new articles. This is the simplest method to get rid of wastes. For example, old books, newspapers, magazines etc. are purchased regularly by paper mills to manufacture new paper.

2. Composting
All types of organic wastes such as peelings of fruits and vegetables, fallen leaves of plants and faecal matter of domestic animals and human beings can be used to prepare manure called compost.

3. Gobar Gas Plants
 Cow dung and other agricultural wastes can be placed in gobar gas plants to produce gobar gas and manure.

4. Landfills
 We can also get rid of wastes by burying it in low lying areas of city.

5. Incineration
Incineration is the process of reducing volume of household, chemical and biological wastes by burning it at high temperature. Incineration is carried out in a special kind of furnace called incinerator. During this process, the large volume of wastes is reduced into small amount of ash which is disposed of as landfill.

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Soil pollution may be defined as the contamination of soil with foreign materials which deteriorates the quality, texture and mineral contents of the soil.

Sources of Soil Pollution

Soil pollution is mainly caused by:

1. Solid wastes
2. Insecticides and weedicides
3. Fertilizers and
4. Industrial wastes

1. Solid Wastes
  The main source of soil pollution is solid waste. Examples of solid wastes are garbage, empty cans, broken furniture, bottles, ash, building materials, radioactive wastes, paper, clothes, leather, plastics etc. Solid wastes generally come from industries, houses, agricultural fields and nuclear reactors.

2. Insecticides and Weedicides
 These days, various types of insecticides and weedicides are used to improve agricultural production. When insecticides and weedicides are sprayed over the plants, some part of them gets mixed with soil and cause soil pollution.

3. Fertilizers
 Excessive use of fertilizers in modern agriculture also causes soil pollution. Generally, all the fertilizers are non-biodegradable. So, they accumulate in soil and make it toxic.

4. Industrial Wastes
Every year a large amount of solid and liquid wastes is dumped over the soil by various industries. These wastes contain many toxic materials such as lead, mercury, cadmium, cyanides, acids, alkalies etc. Thus, industrial wastes also cause soil pollution.

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