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[CENTER]The deteriorating environment[/CENTER]

By Anas Bin Tahir


The undesirable changes in the physical chemical and biological characteristics of air, water and soil are called pollution. In other words, the contamination of earth’s environment with materials that interfere with human health, the quality of life or the natural functioning of living organisms and their surroundings is known as pollution.

Natural processes like volcanic erruption cause environmental pollution, but more is due to anthropogenic (human) activities. Substances which are harmful to the environment when added to the atmosphere in harmful proportions cause pollution. These substances are called pollutants. Some pollutants are not very harmful; they break up into simpler compounds and mix up with the soil, such as sewage waste, etc. These are called as “Bio degradable pollutants”. If they are released in harmful proportions they can create some problems. Some of the pollutants do not decompose or do very slowly, including pesticides, aluminium cans, plastic bags and rubber products. Their composition changes into more toxic compounds. They are called “Non-biodegradable” and act as permanent sources of pollution.

Air pollution

Contamination of earth’s atmosphere is known as air pollution. It has existed since humans first began to use fire for heating and cooking, but with the increase in population and industrial revolution in the 18th and 19th centuries, air pollution has become a major problem.

There are some gases, which are harmful for the atmosphere. The main sources of these gases are vehicle exhaust, industrial smoke, fire extinguishers, refrigerants, pesticides and burning of fuels, plastics and rubber. Automobiles and industries are the chief contributors. In humid areas air pollution causes a mist called smog. Smog is a mixture of solid particle of smoke with liquid fog.

In humidity, when the air is calm, the smoke accumulates near the sources, and remains near the earth’s surface. By the burning of fuel in cars and trucks, nitrogen oxide is produced. If the fuel is not totally combusted it produces hydrocarbons. Nitrogen oxide, in the presence of hydrocarbons, produces ozone, and such materials, which condense and form a visible pungent haze. This process takes place in sunlight therefore it is known as “Photochemical smog”. This condition may cause irritation in the eyes and reduce visibility during daytime. It may cause breathing problems, dizziness and headaches.

Another effect of air pollution is “Acid rain”. There are certain gases like nitrogen oxide and sulphur trioxide, which are deposited in the atmosphere. When mixed with rainwater during rains they form acids. The main sources of these gases are automobile and industrial smoke. Acid rains damage the marble and stone monuments and buildings. They also affect human life and cause lung cancer. Acid rains cause fish and plants to decay, as they can not sustain more acidity. Eventually lakes and forests become lifeless. Heavily industrial areas like Europe, Eastern US and Canada are the hardest hit by these acid rains.

One of the greatest challenges caused by air pollution is “Global warming”. It is an increase in earth’s temperature. Most of the pollutant gases, for example, gases from automobiles, fire extinguishers and refrigerants, have the ability to trap the rays of the sun and reflect them back to the earth’s atmosphere. This causes an increase in earth’s temperature. Carbon dioxide is the most harmful gas in this case. It is believed that if the level of these gases is not controlled the temperature of the earth will rise causing severe problems. The sea level will rise due to the melting of polar ice damaging the coastal areas. Regional changes will result in the loss of food due to draught.

Another effect on the environment is “Ozone shield destruction” Ozone is a protective covering around the earth. It protects the earth from the harmful rays of the sun. There are some pollutant gases, which attack this ozone shield. Chief among them are those gases which contain chlorine. Mostly they come from the refrigerants (notably from air conditioners) fire extinguishers and propellant gases from spray cans. A single chlorine atom may destroy up to 100,000 ozone molecules.

Ozone shield destruction will cause UV rays to penetrate the atmosphere. It will cause skin cancer, destruction of plants and animals. Pesticides are very harmful for the birds and useful insects. When they remain in the air for longer period of time fruits and crops also bear their poisonous effects. These fruits and vegetables when consumed by humans can cause dangerous diseases.

Water pollution

Water pollution is the contamination of streams, lakes, oceans and ground water by the substances which are harmful to living organisms. Water pollution has more severe effects than air pollution. All living organisms need water for their survival, some live in it while others drink it. They cannot survive if the water is loaded with toxic materials. It is found that 80 per cent of diseases affecting human beings are caused by drinking impure water.

There are three main causes of water pollution.

-- Industries: In many industrial areas the toxic waste and radioactive compounds are thrown into nearby water reservoirs, without proper treatment. This directly affects the fish and other aquatic organisms. Sometimes water is used to cool the machines in the factories. The hot water is released into the lakes or rivers. This hot water heats the water in lakes and harms the aquatic animals and plants.

When industrial waste is buried underground, the toxic liquid seeps into the ground water.

This water also becomes unfit for domestic purposes. Due to offshore mining and oil carrying ships, oil spills into the ocean water badly affects the fish as well as the birds feeding on these fish.

-- Sewage waste: It consists of human waste, garbage and the water that has been used for washing and bathing. Detergents and germs present in garbage and human waste are highly harmful. They can cause diseases like cholera, dysentery, typhoid fever and diarrhoea. These diseases are more common in areas where people drink water from lakes or streams.

-- Agricultural chemicals and waste: When snow melts the water flows into the streams, carrying chemical fertilizers and pesticide remains. These are harmful to animals and humans. Wastage dumping at the seaside is a usual practice. People throw trash, metal cans, bottles and wrappers. They are taken as food by the fish, resulting in the death of these fish.

Soil pollution

Destruction of earth’s fertile layer of soil is called soil pollution. This fertile layer has useful nutrients and micro organisms that are essential for plant growth. Damage to this fertile layer will cause damage to the plant growth. Soil pollution is mostly caused by the build-up of toxic chemicals, excessive salts, pathogens and radioactive material in the soil.

Acid rains make the soil more acidic leaving it unfit for plantation. Soil pollution is also a result of poor drainage system. When water, standing in fields, evaporates, it leaves the salts in soil. The soil becomes more salty and unhealthy for plants and trees. One of the main effects of soil pollution is reduction of forests and plants, resulting in an increase in more carbon dioxide.

Noise pollution

Unwanted sound or noise such as produced by airplanes, traffic or industrial machinery is also considered a form of pollution. Noise pollution is at its worst in densely populated areas. Human ear can detect a sound at a frequency between 20hz and 20,000hz. High frequency sounds tend to be more hazardous and more annoying. Noise pollution is more harmful for human beings as compared to animals. It can cause loss of hearing, stress, high blood pressure, sleep loss and distraction. These diseases are more common in industrial areas.

Radiation pollution

Radiation materials leave a negative impact on environment. The main source of radioactivity is radioactive dust, which falls to earth after atomic explosions. These explosions produce some short-lived particles but most of them remain active for a long time. Ozone shield destruction allows UV and Infrared radiation to come into the earth’s atmosphere. Radiation waste thrown in water from nuclear plants cause radiation pollution in water. The effect of radiation is very harmful for all living things. Some forms of radiation have the ability to destroy living cells. This results in various skin diseases. Radiation also harms the vegetation and disturb plant growth. From plants or by direct exposure the radioactive elements can harm the animals. A radioactive particle, strontium-90, if enters the animal’s body harms the bone marrow. Because of this, blood production is affected and it may result in leukaemia. Radiation can cause mutations, particularly in humans. Abnormalities and death may result in the off springs of the people exposed to radiation. Temporary baldness is also the result of radioactivity.

Control measures

Pollution in its various forms is increasing tremendously day by day and the environment is deteriorating due to industrial pollution, toxic waste released into it, automobile exhaust and natural resource depletion. Measures should be adopted to control and reduce the pollution to make air fit for breathing, availability of healthy water for drinking and managing soil and ocean resources. Some of them are:

1. Consciousness and legislation: Most of the problems caused by pollution are local and by creating consciousness can be controlled very effectively. Everyone should be made aware of the ill-effects of pollution so that individual efforts are made to control it. Similarly laws against pollution should be formulated and implemented very stringently.

2. Recycling: Objects like aluminium cans, glass bottles, papers and things made of iron can be recycled. It helps to conserve raw material.

3. Control of air pollutants: Automobiles are the main source of air pollution. Gas should be used instead of petrol, especially diesel. Engines should be kept in perfect order so that there is minimum emission of smoke. Industries should reduce the use of coal; and devices to minimise the escape of solid smoke particles must be used. Smoking should be banned as tobacco pollutes the air and cause diseases even in non smokers.

4. Control over water pollutants: Treatment plants should be constructed so that sewage and industrial waste is made free of non-degradable pollutants and then thrown into water. Washing chemicals which cause less pollution should be used. Dumping trash in oceans musty be banned. No toxic chemical should be allowed to spill in the water.

5. Control of noise pollution: Plants are efficient absorbers of noise, so plantation on both sides of highways and streets can decrease noise pollution. Industrial areas should be located outside the city limits. this would also help in reducing air pollution as trees absorb carbon dioxide and release oxygen.

6. Control on radioactivity: Radioactive waste must be disposed off in a manner that would not be able to cause harmful impacts. It can be buried in lead cans. Nuclear or atomic explosion should be banned as they produce long lasting harmful effects.

7. Forestry: Deforestation should be banned. Industries using timber should be compelled to plant more trees.

8. Control over use of pesticides: Pesticide sprays should be used in limited amount. Techniques of genetic engineering should be used for pesticide production. Beneficial insects that eat up the harmful insects should not be harmed.

9. Control on population growth rate: The tremendous rise in population is much at the base of pollution problem. With the increase in population we need more houses, and more transport that emits smoke. Naturally forests are reduced to make house and roads which result in more carbon dioxide and less fresh air.


Courtesy: DAWN newspaper.