NORTH SOUTH UNIVERSITY
Project on Air Pollution
Prepared for: Dr. S.M. Mostafa Kamal Khan (SKK)
Introduction to Pollution:
What is Pollution?
Pollution is the introduction of contaminants into the natural environment that causes adverse change. Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Air Pollution:
Air pollution is the introduction into the atmosphere of chemicals, particulates, and biological matter that cause harm to humans, other living organisms, or cause damage to the natural environment. Stratospheric ozone depletion (contributed to air pollution) has long been recognized as a threat to human health as well as to the Earth’s ecosystems.
Causes Of Air Pollution:
a) 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. Sources:
Ozone is not created directly, but is formed when nitrogen oxides and volatile organic compounds mix in sunlight. That is why ozone is mostly found in the summer. Nitrogen oxides come from burning gasoline, coal, or other fossil fuels. b) Carbon monoxide - A gas that comes from the burning of fossil fuels, mostly in cars. It cannot be seen or smelled. Sources:
Carbon monoxide is released when engines burn fossil fuels. Emissions are higher when engines are not tuned properly, and when fuel is not completely burned. Cars emit a lot of the carbon monoxide found outdoors. Furnaces and heaters in the home can emit high concentrations of carbon monoxide, too, if they are not properly maintained.
c) Nitrogen dioxide - A reddish-brown gas that comes from the burning of fossil fuels. It has a strong smell at high levels. Sources:
Nitrogen dioxide mostly comes from power plants and cars. Nitrogen dioxide is formed in two ways—when nitrogen in the fuel is burned, or when nitrogen in the air reacts with oxygen at very high temperatures. Nitrogen dioxide can also react in the atmosphere to form ozone, acid rain, and particles.
d) Particulate matter - Solid or liquid matter that is suspended in the air. Sources:
Particulate matter can be divided into two types—coarse particles and fine particles. Coarse particles are formed from sources like road dust, sea spray, and construction. Fine particles are formed when fuel is burned in automobiles and power plants.
e) Sulfur dioxide - A corrosive gas that cannot be seen or smelled at low levels but can have a “rotten egg” smell at high levels. Sources:
Sulfur dioxide mostly comes from the burning of coal or oil in power plants. It also comes from factories that make chemicals, paper, or fuel. Like nitrogen dioxide, sulfur dioxide reacts in the atmosphere to form acid rain and particles.
f) 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. Sources:
Carbon dioxide is the most important greenhouse gas. It comes from the burning of fossil fuels in cars, power plants, houses, and industry. Methane is released during the processing of fossil fuels, and also comes from natural sources like cows and rice paddies. Nitrous oxide comes from industrial sources and decaying plants.
Effects of Air Pollution:
a) Acid Rain: Acid rain describes any form of precipitation with high levels of nitric and sulfuric acids. It can also occur in the form of snow, fog, and tiny bits of dry material that settle to Earth. The biggest cause of acid rain is burning of fossil fuels by...
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