• ATMOSPHERE• Air• Air Pollution• Pollutant• Classification of Air Pollutant• Sources of Air Pollutant• Effects of Air Pollutant• How to Reduce Air Pollution
“ATMOSPHERE”• The atmosphere is an envelope of gases that surrounds the earth. The air we breathe is the part of atmosphere. Scientists have divided the atmosphere into four main parts, each with its own characteristics. They are:• Troposphere• Stratosphere• Mesosphere• Thermosphere
Troposphere:• The layer of atmosphere that touches the surface of earth is called “Troposphere”. The troposphere extends to a height of about 11 kilometers above the surface of earth.• Most of the living organisms come under troposphere. This layer contains most of the water vapors in the atmosphere and this is only the layer in the atmosphere where weather changes occur.
Stratosphere:• Beyond the troposphere, reaching at a height of about 50 kilometers above the surface of earth is Stratosphere. Most jet planes travels in the lower level of stratosphere. The upper level of stratosphere contains a layer of gases called OZONE.
Mesosphere:• After the layer of stratosphere, there is another layer called Mesosphere which is extended up to 85 kilometers above the surface of earth. The mesosphere is the coldest layer of the atmosphere.• Due to decreasing solar heating and increasing cooling by CO2 radiative emission, the mesopause (top of the mesopshere layer is the coldest place on Earth. Temperatures in the upper mesosphere fall as low as −100 °C.
Thermosphere:• Thermosphere is the most outer layer of atmosphere. Unlike the mesosphere, thermosphere has a very high temperature reaching up to “2000 oC”
What do we know about “Air”• Atmosphere is the column of air that surrounds the earth, starting from the surface of earth to the altitude approximate: 11 km called Troposphere. Air is blanket of gases that contain:• Nitrogen 78.09% by volume, Oxygen 20.94% by volume and other gases like Carbon, Argon, Neon, Helium, Methane, etc. These are in pure and perfect harmony.
What is Air Pollution?Addition of harmful substances to the atmosphereresulting in damage to the environment, humanhealth, and quality of life. One of many forms ofpollution, air pollution occurs inside homes,schools, and offices; in cities; across continents;and even globally.
• Air pollution makes people sick—it causes breathing problems and promotes cancer— and it harms plants, animals, and the ecosystems in which they live. Some air pollutants return to Earth in the form of acid rain and snow, which corrode statues and buildings, damage crops and forests, and make lakes and streams unsuitable for fish and other plant and animal life.
What do we mean by the term pollutant?• Substance that causes pollution or unwanted occurrence that affects a person’s surroundings unfavorably.• Due to natural and man-made pollution, the air is never found clean in the atmosphere. Gases such as CO, SO2 and H2O are continuously releases into the atmosphere through natural activate (Volcanic activity, Vegetation decay and Forest fires). Tiny particles of solids and liquids are distributed throughout the air by winds, volcanic explosion and other similar natural disturbances.
What are the pollutants that cause air pollution?There are six common air pollutants:• Sulphur dioxide• Carbon Monoxide• Nitrogen oxides• Lead• Ozone• Particulates
Where do these pollutants come from?Sulphur dioxide Carbon monoxide
Ozoneis formed by a chemical reaction between nitrogen oxidesand (VOC) volatile organic compounds in the presence of sunlight.
Particulates:• Particulates are made up from nitrates and sulphates, metals, soil, dust.
Classifications of Air Pollutants:• PRIMARY AIR POLLUTANTS• SECONDARY POLLUTANTS• PRIMARY AIR POLLUTANTS:• Some important primary air pollutants are:• Sulfur Oxides (SOX), particularly Sulfur dioxide (SO2)• Carbon Mono Oxide (CO)• Nitrogen Oxides (NOX)• Lead• Hydrocarbons• Radio Active substances• Hydrogen Sulfide• Hydrogen Fluoride
SECONDARY POLLUTANTS:• Some important secondary air pollutants are:• Sulfuric Acid (H2SO4)• Ozone (O3)• Nitric Acid
SOURCES OF SOME IMPORTANT AIR POLLUTANTS:• Pollutant: Carbon Mono Oxide (CO)• Major Source: Incomplete combustion of fuel, automobile exhaust, jet engine emission, mines• and tobacco smoking.• Pollutant: Sulfur dioxide (SO2)• Major Source: Combustion of coal, Combustion of Petroleum products, Oil Refinery, Power• House (Coal), Sulfuric Acid Plants, and Domestic burning fuels• Pollutant: Nitrogen Oxide (NOX)• Major Source: Automobile exhaust, Gas fire furnace, Fertilizer Industry.
SOURCES OF SOME IMPORTANT AIR POLLUTANTS:• Pollutant: Ammonia (NH3)• Major Source: All chemical Industries• Pollutant: Hydrogen Sulphide (H2S)• Major Source: Petroleum Industry, Coal Ovens, Oil refinery, Sewage Treatment Plant• Pollutant: Hydrocarbons (HC)• Major Source: Organic Chemical Industry, Petroleum Refinery• Pollutant: Carbon dioxide (CO2)• Major Source: Combustion of Fuel, Jet engine emission.•
SOME IMPORTANT AIR POLLUTANTS AND THEIR EFFECTS:• Pollutant: Carbon Mono Oxide (CO)• Effects: Toxicity (poisonous) caused blood poisoning.• Pollutant: Sulfur dioxide (SO2)• Effects: Increasing the breathing rate, Suffocation, asthma, Irritation of eyes.• Pollutant: Nitrogen Oxide (NOX)• Effects: Respiratory Irritation, Headache, Corrosion of Teeth• Pollutant: Carbon dioxide (CO2)• Effects: Toxic in large quantities.
SOME IMPORTANT AIR POLLUTANTS AND THEIR EFFECTS:• Pollutant: Hydrogen Sulphide (H2S)• Effects: Headache, Eyes pain, Irritation Aspiratory.• Pollutant: Ammonia (NH3)• Effects: Affects Respiratory System, Eyes Irritation.• Pollutant: Hydrocarbons (HC)• Effects: Cancer
What Can We Do To Reduce Air Pollution?Walking or cycling whenever you can willbe even more beneficial, as it does not create any pollution. It willalso benefit your body, as regular exercisewill keep you fit and healthy.•Use buses and trains instead of cars, as theycan carry far more people in one journey. Thiscuts down the amount of pollution produced.
Avoid using cars for very short journeys as this createsunnecessary pollution.If car journeys must be made, then try to share yourjourneys with other people, such as when you go shopping. Also encourage people to drive more slowly as thisproduces less pollution.We can also help prevent pollution from our own homes.Turning off lights when they are not needed and not wastingelectricity will reduce the demand. Less electricity will need to be produced and so less fossil fuelwill have to be burnt, resulting in less air pollution.