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Air pollution. What is Air?. Air is a mixture of gases containing about 78 percent nitrogen; 21 percent oxygen; less than 1 percent of argon & carbon dioxide, and other gases; and varying amounts of water vapor. . What is Air Pollution?.
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What is Air? Air is a mixture of gases containing about 78 percent nitrogen; 21 percent oxygen; less than 1 percent of argon & carbon dioxide, and other gases; and varying amounts of water vapor.
What is Air Pollution? • Air Pollution is the degradation of air quality resulting from unwanted chemicals or other materials occurring in the air. • It is the contamination of air by the discharge of harmful substances.
Beginning of Air Pollution The Industrial Revolution in Europe in the 19th century saw the beginning of air pollution as we know it today, which has gradually become a global problem. Air pollution is aggravated because of four developments: • increasing traffic, • growing cities, • Rapid economic development, and • industrialization.
Major Air Pollutants • Carbon monoxide (CO) • Carbon dioxide (CO2) • Chlorofluorocarbons (CFC) • Lead • Ozone • Nitrogen oxide (Nox) • Suspended particulate matter (SPM) • Sulphur dioxide (SO2)
Major Air Pollutants and their Sources. • Carbon monoxide (CO)- colorless, odorless gas • Produced by the incomplete burning of carbon-based fuels including petrol, diesel, and wood. • Also produced from the combustion of natural and synthetic products such as cigarettes. • Motor vehicles are the main source of carbon monoxide pollution in urban areas.
Health effects • Highly poisonous gas • Harmful for all Living Organisms
Major Air Pollutants and their Sources. • Carbon dioxide (CO2) • principle greenhouse gas • Produced by burning of coal, oil, and natural gases. • volcanoes release about 130-230 million tonnes of CO2 into the atmosphere each year. • Excess can lead to Global Warming. • A new study details how for each increase of one degree Celsius caused by carbon dioxide, the resulting air pollution would lead annually to about a thousand additional deaths and many more cases of respiratory illness and asthma in the world.
Major Air Pollutants and their Sources. • Chlorofluorocarbons (CFC) Produced from air-conditioning systems and refrigeration. Main Reason behind Ozone Layer Depletion. • Lead present in petrol, diesel, lead batteries, paints, hair dye products, etc. affects children in particular. cause nervous system damage and, in some cases, cause cancer. • Ozone Vehicles and industries are the major source Ozone. Makes our eyes itch, burn, and water. It lowers our resistance to colds and pneumonia.
Major Air Pollutants and their Sources. • Nitrogen oxide (Nox) • causes smog and acid rain. • produced from burning fuels including petrol, diesel, and coal. • make children susceptible to respiratory diseases in winters. • Suspended particulate matter (SPM) • consists of solids in the air in the form of smoke, dust, and vapour that can remain suspended for extended periods and is also the main source of haze which reduces visibility. The finer of these particles, when breathed in can lodge in our lungs and cause lung damage and respiratory problems.
Major Air Pollutants and their Sources. • Sulphur dioxide (SO2) • produced from burning coal, mainly in thermal power plants. • Some industrial processes, such as production of paper and smelting of metals, produce sulphur dioxide. • It is a major contributor to smog and acid rain. Sulphur dioxide can lead to lung diseases. Emissions from industry and power generation based on fossil fuel contain sulphur dioxide
Natural Causes Air pollution results from a variety of causes, not all of which are within human control. The natural causes of Air Pollution are: • Dust storms in desert areas and smoke from forest fires and grass fires • Volcanic activity
Forest Fires causing Air Pollution Contributes to chemical and particulate pollution of the air. The source of pollution may be in one country but the impact of pollution may be felt elsewhere. The discovery of pesticides in Antarctica, where they have never been used, suggests the extent to which aerial transport can carry pollutants from one place to another.
Volcanic Eruptions The most important natural source of air pollution is volcanic activity, which at times pours great amounts of ash and toxic fumes into the atmosphere.
Human Causes • Transportation • Factories and Industrial Factors
Effects of Air Pollution • Smog • Acid Rain • Global Warming
Smog over Los Angeles Los Angeles smog on 29 January 2004. The top of the inversion layer is easily seen against the backdrop of distant mountains. Hilltops above the layer are visible at great distances, urban areas below the layer are obscured. This is what the smog in Los Angeles looks like from the ground, a thick brown or slightly orange haze with a strong smell of ozone. In this scene, the inversion is below the top of the highest buildings. The exhaust from more than a million cars driven in the morning rush hour is trapped below this level.
Indoor Air Pollution It refers to the physical, chemical, and biological characteristics of air in the indoor environment within a home, building, or an institution or commercial facility. Sources of indoor air pollution->Tobacco smoke, cooking and heating appliances, and vapors from building materials, paints & furniture causes
Control Measures: • Shift to less polluting forms of power generation, such as solar energy, wind energy, geothermal, tidal and other forms of renewable energy in place of fossil fuel can be used for controlling pollution. • Many cities in India now have pollution control checks for vehicles. Cars are being fitted with catalytic converters and unleaded petrol is being used. There is an attempt to keep a check on polluting industrial units by the judiciary. Cars that use CNG have also been introduced.
What we can do….. • Conserve energy. Walk or ride a bicycle • Look after the trees in your neighborhood. Plant more trees and tend to them too. • Switch off the lights and fans each time you leave a room.
