Pollution is the introduction of harmful materials into the environment. These toxic materials are pollutants. Pollutants can be natural, such as volcanic ash. Human activity, such as factories producing trash or runoff, can also create them. Pollutants damage the quality of air, water, and land.

Air Pollution

Air is very important for all living beings. One can survive without food for a few days, but without air one cannot survive even for a few minutes. Thus clean air is essential for all of us.

The air around us is a mixture of different gases in a fixed proportion. This proportion remains constant due to many natural processes such as photosynthesis, respiration etc. This balance disturbance contaminates the air.

When the introduction of chemicals, particulate matter, or biological materials contaminates the air and causes harm or discomfort to humans or other living organisms, or damages the natural environment.

Causes and Consequences of Air Pollution

The substances which contaminate the air are air pollutants. Sometimes, such substances may come from natural sources like smoke and dust arising from forest fires or volcanic eruptions.

Human activities are also responsible for adding pollutants to the environment. The main sources of air pollutants are factories, power automobile exhausts and the burning of firewood and dung cakes.

Exhaust from Vehicles

The exhaust from vehicles produces high levels of carbon monoxide, carbon dioxide, oxygen dioxide, and smoke. Fuels such as petrol and diesel produce carbon monoxide through incomplete burning. It is a poisonous gas. It reduces the oxygen-carrying capacity of the blood. You might have observed a thick fog-like layer in the atmosphere, especially during winter. This is smog, which consists of smoke and fog. Smoke may contain oxides of nitrogen which combine with other air pollutants and fog to form smog. The smog not only reduces visibility but also causes breathing difficulties such as asthma, cough and wheezing in children.

Exhaust from industries

Many industries are also responsible for causing air pollution. Petroleum refineries are a major source of gaseous pollutants like sulphur dioxide and nitrogen dioxide.Power plants produce sulphur dioxide and nitrogen dioxide through the combustion of fuels like coal.They can cause respiratory problems, including permanent lung damage.

Moreover, pollutants like sulphur dioxide and nitrogen dioxide react with the water vapour present in the atmosphere to form sulphuric acid and nitric acid. These acids mix with the rainwater and fall with rain, making it acidic. This is acid rain.

Acid rain makes the soil acidic and affects the agricultural productivity-

· Acid rain damages the forest trees.

· It damages the aquatic life. The water in lakes, ponds or rivers or more acidic and unsuitable for animals and plants surviving there.

· Acid rain promotes the corrosion of metallic structures such as railway bridges, towers etc.

· It kills fish and other aquatic animals and plants

· Acid rain lowers the fertility of the soil.

Acid rain corrodes the marble of the monument. The phenomenon is marble cancer.

Pollutants from Home

CFCs (chlorofluorocarbons) are used in refrigerators, air conditioners, and aerosol sprays as other types of pollutants. CFCs damage the ozone layer of the atmosphere. The ozone layer protects us from the harmful ultraviolet rays of the sun. Damage to the ozone layer is a serious matter of concern. Every time even a small amount of the ozone layer is depleted, the ultraviolet rays entering the earth’s atmosphere make human beings and other animals vulnerable to skin cancer.

Suspended Particulate Matter

In addition to the above-mentioned gases, automobiles which burn diesel and petrol also produce tiny particles that remain suspended in the air for long periods. They reduce visibility and cause diseases when inhaled. Industrial processes like steel making and mining produce such particles as well. Power plants give out tiny ash particles. Suspended particulate matter pollute the atmosphere.

Industries like Rubber processing. Automobiles, Chemicals and especially the Mathura oil refinery, located in and around Agra have pollutants like sulphur dioxide, which on reacting with the moisture of air forms sulphuric acid. It is Corroding the beauty of the Taj.

Not only the Taj Mahal but other world-famous monuments such as Cologne Cathedral, Notre Dame, the Colosseum and Westminster Abbey have all been affected by similar pollution.

Industries and automobile owners around the monuments of the Supreme Court of India must take strict measures. They must switch to cleaner fuels like compressed natural gas (CNG) and liquefied petroleum gas (LPG). The authorities instruct vehicles in the La zone to use lead-free petrol. The Supreme Court of India has banned vehicles within a certain metre radius of the monuments.

It is not only living organisms that get affected by polluted air but non-living things buildings, monuments and statues also get affected. India’s most famous tourist attraction, the Taj Mahal in Agra, has become a matter of concern due to increasing air pollution. Researchers from the United States and India reported that dust and carbon particles are causing discoloration on the marble dome and minarets of the Taj Mahal turning the white color Of this landmark to brown.

Greenhouse effect

The earth absorbs and reflects a part of the radiation that falls on it into space. The atmosphere traps a part of the radiation reflected from it. This trapped heat warms the earth just like the heat trapped by a greenhouse (or the chamber of glass) in a nursery warms it. The trapping of radiations by the earth’s atmosphere is similar to this. That is why it is called the greenhouse effect.

Human activities continuously release carbon dioxide. On the other hand, the area under forests is decreasing. Plants utilize carbon dioxide from the atmosphere for photosynthesis, thereby decreasing its amount in the air. The reduction in the number of trees leads to an increase in the amount of carbon dioxide in the air. Human activities, thus, contribute to the accumulation of carbon dioxide in the atmosphere. It traps heat and does not allow it to escape into space. As a result, the average temperature of the earth’s atmosphere is gradually increasing. This is called global warming.

Other gases like methane, nitrous oxide and water vapours also contribute to global warming. These are called greenhouse gases.

Prevention and Control of Air Pollution

We cannot allow air pollution to prevail without restrictions. We can, however, control it to minimize its harmful effects.

Some ways to control air pollution are suggested as follows:

Implementing regulations on industrial emissions

Planting more trees

Encouraging the use of public transportation

Implementing stricter emissions standards for industries

Promoting the use of renewable energy sources

Encouraging carpooling and telecommuting

Improving the quality of fuels in automobiles and using catalytic converters in them. The use of CNG in automobiles has reduced air pollution in our metro cities considerably.

Replacing wood, coal and kerosene with LPG for domestic use.

Using alternative sources of energy like solar, wind, and thermal energy.

Using better technology to control the level of pollutants in the emissions.