AIR POLLUTION

Air pollution, release into the atmosphere of various gases, finely divided solids, or finely dispersed liquid aerosols at rates that exceed the natural capacity of the environment to dissipate and dilute or absorb them. These substances may reach concentrations in the air that cause undesirable health, economic, or aesthetic effects. 

It occurs when any harmful gases, dust, smoke enters into the atmosphere and makes it difficult for plants, animals, and humans to survive as the air becomes dirty. 

Air pollution can further be classified into two sections- visible air pollution and invisible air pollution. Another way of looking at air pollution could be any substance that holds the potential to hinder the atmosphere or the well-being of the living beings surviving in it. The sustainment of all things living is due to a combination of gases that collectively form the atmosphere; the imbalance caused by the increase or decrease in the percentage of these gases can be harmful to survival. 

Types of Pollutants

In order to understand the causes of Air pollution, several divisions can be made. 

• Primary air pollutants can be caused by primary sources or secondary sources. The pollutants that are a direct result of the process can be called primary pollutants. A classic example of a primary pollutant would be the sulfur-dioxide emitted from factories 
• Secondary pollutants are the ones that are caused by the intermingling and reactions of primary pollutants. Smog created by the interactions of several primary pollutants is known to be as a secondary pollutant. 

 Sources of Air pollution

There are two types of sources i.e. Natural sources and Man-made sources;

• Natural sources of pollution include dust carried by the wind from locations with very little or no green cover, gases released from the body processes of living beings (Carbon dioxide from humans during respiration, Methane from cattle during digestion, Oxygen from plants during Photosynthesis). Smoke from the combustion of various inflammable objects, volcanic eruptions, etc along with the emission of polluted gases also makes it to the list of natural sources of pollution.
• Man-made contributions towards air pollution, smoke again features as a prominent component. The smoke emitted from various forms of combustion like in biomass, factories, vehicles, furnaces, etc. Waste used to create landfills generates methane, which is harmful in several ways. The reactions of certain gases and chemicals also form harmful fumes that can be dangerous to the well-being of living creatures. 

Major Air pollutants 

Air pollution is a real public health and environmental problem that can lead to-among other things-global warming, acid rain, and the deterioration of the ozone layer. Some common pollutants are;

1. Ozone: A gas that can be found in two places. Near the ground (the troposphere), it is a major part of smog. The harmful ozone in the lower atmosphere should not be confused with the protective layer of ozone in the upper atmosphere (stratosphere), which screens out harmful ultraviolet rays.
2. Carbon monoxide: A gas that comes from the burning of fossil fuels, mostly in cars. It cannot be seen or smelled.
3. Nitrogen dioxide: A reddish brown gas that comes from the burning of fossil fuels. It has a strong smell at high levels
4. Particulate matter: Solid or liquid matter that is suspended in the air. To remain in the air, particles usually must be less than 0.1-mm wide and can be as small as 0.00005 mm.
5. Sulfur dioxide: A corrosive gas that cannot be seen or smelled at low levels but can have a ―rotten egg smell at high levels.
6. Lead: A blue-gray metal that is very toxic and is found in a number of forms and locations.
7. Toxic air pollutants: A large number of chemicals that are known or suspected to cause cancer. Some important pollutants in this category include arsenic, asbestos, benzene, and dioxin.
8. Stratospheric ozone depleters: Chemicals that can destroy the ozone in the stratosphere. These chemicals include chlorofluorocarbons (CFCs), halons, and other compounds that include chlorine or bromine.
9. Greenhouse gases: Gases that stay in the air for a long time and warm up the planet by trapping sunlight. This is called the ―greenhouse effect because the gases act like the glass in a greenhouse. Some of the important greenhouse gases are carbon dioxide, methane, and nitrous oxide. 

Source: Jonathan Levy, Harvard School of Public Health. Based on information provided by the Environmental Protection Agency.

Causes of Air pollution

 1. The burning of fossil fuels 

Sulfur dioxide emitted from the combustion of fossil fuels like coal, petroleum and other factory combustibles are one the major cause of air pollution. Pollution emitting from vehicles including trucks, jeeps, cars, trains, airplanes cause an immense amount of pollution. We rely on them to fulfill our daily basic needs of transportation. But, their overuse is killing our environment as dangerous gases are polluting the environment. Carbon Monoxide caused by improper or incomplete combustion and generally emitted from vehicles is another major pollutant along with Nitrogen Oxides, which is produced from both natural and man-made processes. 

2. Agricultural activities 

Ammonia is a very common byproduct from agriculture-related activities and is one of the most hazardous gases in the atmosphere. Use of insecticides, pesticides, and fertilizers in agricultural activities has grown quite a lot. They emit harmful chemicals into the air and can also cause water pollution. 

3. Exhaust from factories and industries 

Manufacturing industries release a large amount of carbon monoxide, hydrocarbons, organic compounds and chemicals into the air thereby depleting the quality of air. Manufacturing industries can be found at every corner of the earth and there is no area that has not been affected by it. Petroleum refineries also release hydrocarbons and various other chemicals that pollute the air and also cause land pollution. 

4. Mining operations 

Mining is a process wherein minerals below the earth are extracted using large equipment. During the process dust and chemicals are released in the air causing massive air pollution. This is one of the reasons which are responsible for the deteriorating health conditions of workers and nearby residents. 

5. Indoor air pollution 

Household cleaning products, painting supplies emit toxic chemicals in the air and cause air pollution. Suspended particulate matter (SPM) is another cause of pollution. Referring to the particles afloat in the air, SPM is usually caused by dust, combustion, etc. 

 Effects of Air pollution

1. Respiratory and heart problems 

The effects of air pollution are alarming. They are known to create several respiratory and heart conditions along with Cancer, among other threats to the body. Several million are known to have died due to direct or indirect effects of Air pollution. Children in areas exposed to air pollutants are said to commonly suffer from pneumonia and asthma. 

2. Global warming 

Another direct effect is the immediate alterations that the world is witnessing due to global warming. With increased temperatures worldwide, increase in sea levels and melting of ice from colder regions and icebergs, displacement and loss of habitat have already signaled an impending disaster if actions for preservation and normalization aren't undertaken soon. 

3. Acid rain

Harmful gases like nitrogen oxides and sulfur oxides are released into the atmosphere during the burning of fossil fuels. When it rains, the water droplets combine with these air pollutants becomes acidic and then falls on the ground in the form of acid rain. Acid rain can cause great damage to human, animals, and crops. 

4. Eutrophication 

Eutrophication is a condition where a high amount of nitrogen present in some pollutants, gets developed on sea‘s surface and turns itself into algae and adversely affect fish, plants and animal species. The green colored algae that are present on lakes and ponds are due to the presence of this chemical only. 

5. Effect on wildlife 

Just like humans, animals also face some devastating effects of air pollution. Toxic chemicals present in the air can force wildlife species to move to a new place and change their habitat. The toxic pollutants deposit over the surface of the water and can also affect sea animals. 

6. Depletion of the ozone layer 

Ozone exists in the Earth‘s stratosphere and is responsible for protecting humans from harmful ultraviolet (UV) rays. Earth‘s ozone layer is depleting due to the presence of chlorofluorocarbons, hydro chlorofluorocarbons in the atmosphere. As the ozone layer will go thin, it will emit harmful rays back on earth and can cause skin and eye related problems. UV rays also have the capability to affect crops.

 Solutions For Air Pollution 

1. Use public mode of transportation 

Encourage people to use more and more public modes of transportation to reduce pollution. Also, try to make use of carpooling. If you and your colleagues come from the same locality and have same timings you can explore this option to save energy and money. 

2. Conserve energy 

Switch off fans and lights when you are going out. A large number of fossil fuels are burnt to produce electricity. You can save the environment from degradation by reducing the number of fossil fuels to be burned. 

3. Understand the concept of Reduce, Reuse and Recycle 

Do not throw away items that are of no use to you. In-fact reuses them for some other purpose. For e.g. you can use old jars to store cereals or pulses. 

4. Emphasis on clean energy resources

Clean energy technologies like solar, wind and geothermal are on high these days. Governments of various countries have been providing grants to consumers who are interested in installing solar panels for their home. This will go a long way to curb air pollution. 

5. Use energy efficient devices 

CFL lights consume less electricity as against their counterparts. They live longer, consume less electricity, lower electricity bills and also help you to reduce pollution by consuming less energy.

 Air pollution: a global problem

Air pollution is a major global environmental risk to our health and food security. It is estimated to cause about 3.7 million premature deaths worldwide and destroys enough crops to feed millions of people every year. Health officials, the general public and farmers need advance notice when dangerous air quality levels are on the rise. 

Researchers and engineers at the National Center for Atmospheric Research (NCAR), in collaboration with other agencies, are dedicated to developing new technologies that directly help decision-makers plan for high-pollution days. Air pollution kills an estimated seven million people worldwide every year. WHO data shows that 9 out of 10 people breathe air containing high levels of pollutants. WHO (World Health Organization) is working with countries to monitor air pollution and improve air quality. From smog hanging over cities to smoke inside the home, air pollution poses a major threat to health and climate. The combined effects of ambient (outdoor) and household air pollution cause about seven million premature deaths every year, largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections. More than 80% of people living in urban areas that monitor air pollution are exposed to air quality levels that exceed WHO guideline limits, with low- and middle-income countries suffering from the highest exposures, both indoors and outdoors.