Environmental pollution

Air/Atmospheric Pollution

• Air pollution is the release of harmful or toxic substances into the environment which contaminate the air and the atmosphere as a whole.
• The atmosphere is made up of a mixture of gases generally referred to as air. These gases are Nitrogen, Oxygen, Argon Carbon IV oxide, Methane, Water vapor, and Neon, When there is an increase or a decrease in the levels of any of these gaseous components or the introduction of foreign gases, solids, and liquids into the atmosphere, the air can be described as polluted.
• Common air pollutants are sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, volatile organic compounds, particulate matter, smoke, airborne particles, radioactive pollutants.
• Effects of air pollution are formation of photochemical smog, formation of aerosols, depletion of the ozone layer and enhanced greenhouse gas effects and heath issues.
• Photochemical Smog is formed when hydrocarbons and nitrogen oxides react in the presence of sunlight. It forms a yellowish-brown haze which causes poor visibility and many respiratory disorders and allergies as it contains polluting gases.
• The ozone layer is found in the stratospheric region of the atmosphere. It absorbs the harmful Ultraviolet (UV) rays from the sun and protects life on earth from the harmful effects of the UV rays.
• However, hydrocarbons such as the chlorofluorocarbons (CFCs) form holes in the ozone layer by reacting with ozone in the stratosphere. The holes formed allow direct penetration of UV rays into the troposphere. These rays are carcinogenic. Their effects are visible in the countries such as Australia and New Zealand where the rate of skin cancer is higher than the other regions of the world.
• Aerosols are solids or liquids dispersed in a gaseous medium. Aerosols in the atmosphere are formed by pollutant particulate matter like carbon particles. They form a thick layer in the troposphere that blocks solar radiation, prevents photosynthesis, and changes weather conditions.
• Enhanced greenhouse gas effect results for the presence of excess greenhouse gases (CO2, NOx, SOx CH4, and CFCs) in the troposphere. This increases the temperature of the earth’s surface.