Air Pollution: Definition, Causes, Effects, & Control

Air pollution is defined by the World Health Organization (WHO) as "The presence of harmful substances in the air in such concentrations that are detrimental to man and his environment." Gasses and substances that degrade the air quality are called air pollutants which mainly include particulate matter, ammonia, carbon monoxide, methane, etc. Human activities contributes to many global environmental problems such as ozone depletion, global warming, and climate change. 

• Natural cause of air pollution include forest fires and volcanic eruptions.
• The source of air contaminants are numerous ranging from natural to man-made sources.
• However, the man-made causes are the leading cause of air pollution across the world. 

Check here: Air Pollution Important Questions

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What is Air Pollution?

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Air pollution is a mixture of dangerous elements that come from both natural and man-made sources. The chief sources of human-made air pollution include vehicle emissions, fuel oils and natural gas used to heat houses, by-products of manufacturing and electricity generation, particularly coal-fueled power plants, and odors from chemical production.

Nature releases hazardous substances into the air, such as smoke from wildfires, which are usually triggered by humans; gases and ash from volcanic eruptions; and gases emitted by decomposing organic matter in soils, such as methane.

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Types of Air Pollutants

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There are two types of pollutants in the air: Primary Air Pollutants & Secondary Air Pollutants.

Primary Air Pollutants

Primary pollutants are those that directly contribute to air pollution. They are the direct emissions from a source that can be identified. Carbon monoxide, sulfur oxides, nitrogen oxides, fluorides, chlorofluorocarbons, particulate matter, hydrocarbons, and other pollutants are examples.

Secondary Air Pollutants

Secondary pollutants are pollutants that arise in the atmosphere as a result of photochemical interactions between primary pollutants. Classical smog (London smog), Peroxyacyl Nitrate (PAN), Photochemical smog (Los Angeles smog), acid rain, and so on are examples of smog.

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Causes of Air Pollution

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The following are some of the major sources of air pollution:

Agricultural Activities

One of the most dangerous chemicals released during agricultural activity is ammonia. Insecticides, pesticides, and fertilizers pollute the atmosphere by releasing toxic chemicals.

Factories and Industries

Carbon monoxide, hydrocarbons, organic molecules, and chemicals are mostly produced in factories and industries. These are released into the atmosphere, causing it to deteriorate in quality.

Burning of Fossil Fuels

Sulfur dioxide is produced in significant quantities when fossil fuels are burned. Incomplete burning of fossil fuels releases carbon monoxide, which pollutes the air.

Automobiles

Polluting the environment are the gases generated by vehicles such as trucks, cars, buses, jeeps, lorries, and so on. These are a major source of greenhouse gases, as well as a source of ailments for those who breathe this air. Automobile exhaust contains a lot of hydrocarbons, CO, CO₂, and sulfur oxides.

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Mining Activities

The minerals beneath the earth’s surface are retrieved utilizing enormous pieces of equipment during the mining operation. The dust and chemicals emitted during the operation not only contaminate the air but also harm the employees’ and residents’ health.

Domestic Sources

Painting walls, using wooden sticks as fuel, burning cow dung, and other common household practices all contribute to a noxious odor in the air, posing health risks.

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Effects of Air Pollution

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In the short term, air pollution can produce negative health effects such as irritation of the eyes, nose, and throat, headaches, and allergic reactions. The following are some of the most significant consequences of air pollution:

Diseases

Air pollution causes a variety of respiratory and cardiovascular ailments. Lung cancer, pneumonia, and asthma have all grown in recent years as a result of rising air pollution.

Depletion of the Ozone Layer

Air pollution is responsible for the ozone hole. hydrochlorofluorocarbons, halons, and Chlorofluorocarbons, which are employed as refrigerants, are the primary cause of ozone depletion. This depletion allows the sun's harmful UV radiation to reach the atmosphere, causing skin ailments and vision issues among ordinary people.

Acid Rain

Acid rain has harmed the historic monument, Taj Mahal. The combustion of fossil fuels emits toxic chemicals such as nitrogen oxide and sulfur dioxide into the atmosphere, resulting in acid rain. When water droplets come into contact with this pollutant, they become acidic and fall as acid rain, which has an ecological impact.

Global Warming

The abnormal heating of earth which is brought on by the emissions of greenhouse gases is called global warming. This causes an imbalance in the atmosphere, which causes the Earth's temperature to rise. Carbon dioxide, methane, choloroflurocarbons are some of the examples of greenhouse gases. 

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Control of Air Pollution

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The following are some of the measures that should be taken to reduce air pollution:

Avoid Using Vehicles

Vehicles should not be used for shorter distances. Adoption of e-vehicles is helpful in reducing the carbon emissions. Not only does this reduce pollutants, but it also saves fuel.

Utilization of Clean Energy Resources

Solar, wind, and geothermal energy minimize air pollution to a greater extent. Several countries, notably India, have adopted the utilization of these resources as a means of reducing pollution.

Other strategies to reduce air pollution include:

• By decreasing and minimizing the usage of fire and fire-related goods.
• Another method of reducing pollution is to use alternative fuels. CNG – Compressed Natural Gas – powered vehicles are replacing petrol and diesel in many parts of India. These are typically used by automobiles that aren't fully equipped with low-emission engines.
• Because industrial emissions are a major source of air pollution, the pollutants can be reduced by controlling or treating them at the source. If the reactions of a given raw material produce a pollutant, for example, the raw materials can be replaced with less harmful materials.
• Although India has several procedures aimed at improving air quality, the majority of them are either forgotten or not well implemented. There are still a lot of automobiles on the road that haven't had their emissions tested.
• Controlling pollution at the source isn't always possible. In that instance, process control equipment can be used to reduce pollution.
• Another method of reducing air pollution produced by industry is to upgrade and maintain existing equipment to reduce pollutant emissions.
• Diluting air pollutants is a very effective means of mitigating air pollution.
• The final and most effective method of minimizing the negative impacts of air pollution is tree planting. A vast amount of contaminants in the air are reduced by plants and trees. Planting trees in places with high pollution levels will, in theory, be quite effective.

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Things to Remember

• Air pollution refers to the presence of materials in the air in such concentrations that are detrimental to human beings and their surroundings.
• Air Pollution is caused by both natural and man-made causes. 
• Primary pollutants are those that directly contribute to air pollution. They are the direct emissions from a source that can be identified. Secondary pollutants are pollutants that arise in the atmosphere as a result of photochemical interactions between primary pollutants.
• Air Pollution is caused due to the following activities: Unsafe Agricultural and Mining Practices, emissions from factories and industries, fossil fuel burning, etc.
• Air Pollution leads to negative effects such as health issues like asthma and lung cancer, depletion of the ozone layer, acid rain and global warming.