Sunday, September 14, 2008

causes of air pollution

3.0 AIR POLLUTION CAUSES

Air pollution is not just a “city problem”. Many air pollutants are dispersed over areas hundred of miles from their source where they affect many different ecosystems. These pollutants often remain toxic in the environment for a very long time where they continue to affect ponds, streams, fields, and forests. So, many causes of air pollution and that’s causes can separate to two parts are natural pollution and human activities. Forest fires, volcanic eruptions, wind erosion, pollen dispersal, evaporation of organic compounds, and natural radioactivity are all among the natural causes of air pollution.

3.1 Natural Pollution

Most air pollution is the result of energy consumption. Specifically, the burning of fossil fuels to produce electricity or to power transportation vehicles is the main cause this serious, but preventable, environmental hazard. Example for burning of fossil fuels is forest fires. Well, as you are probably aware, air pollution takes many different forms and arises from a variety of sources. In terms of overall range and extents of impacts. However, burning of fossil fuels is the largest source of air pollutants. These fuels cause smog, acid rain, soot and particulates increases, greenhouse gas emissions, and dispersal of some heavy metal contaminants. Burning of fossil fuels cause acid rain.

Volcanoes commonly displays a distinctive pattern of behavior. Some mild eruptions merely discharge steam and other gases, whereas other eruptions quietly extrude quantities of lava. Other than free oxygen, generated by photosynthesis, all atmospheric gases were derived from inside the earth and released by volcanic eruptions. The gaseous portion of magma varies from ~1 to 5% of the total weight. Water vapor constitutes 70-90%. The remaining gases include CO2, SO2, and trace amounts of of N, H, CO, S, Ar, Cl, and F. These subordinate gases can combine with hydrogen and water to produce numerous toxic compounds.

Wind erosion is a serious environmental problem attracting the attention of many across the globe. It is a common phenomenon occurring mostly in flat, bare areas; dry, sandy soils; or anywhere the soil is loose, dry, and finely granulated. Wind erosion damages land and natural vegetation by removing soil from one place and depositing it in another. It causes soil loss, dryness and deterioration of soil structure, nutrient and productivity losses, air pollution, and sediment transport and deposition.

Radiation is natural. It's in our food, in the air, water, and soil. It's even in our bodies. It comes from unstable atoms-tiny particles of matter. As these atoms break up, they produce invisible energy waves or particles. Our bodies absorb a small amount of this radiation every hour, every day, every week. A person living directly outside a nuclear power facility would receive approximately one additional milligram per year.

3.2 Human Activity

Burning of petroleum in car engines and other petrol runned vehicles releases Carbon monoxide and Carbon dioxide gasses. Carbon Monoxide causes health problems and prolonged exposure to it may result to death. This is so because it inhibits haemoglobin in red blood cells making it incapable of carrying oxygen. Carbon dioxide gas along with other green house gasses such as methane is responsible for greenhouse effect, a process which warms the earth making its climate bearable and capable of sustaining life. But increasing levels of carbon dioxide is believed to result into Global warming.

Photochemical smog is also appearing in regions of the tropics and subtropics where savanna grasses are periodically burned. Smog's unpleasant properties result from the irradiation by sunlight of hydrocarbons caused primarily by unburned gasoline emitted by automobiles and other combustion sources. The products of photochemical reactions includes organic particles, ozone, aldehydes, ketones, peroxyacetyl nitrate, organic acids, and other oxidants. Ozone is a gas created by nitrogen dioxide or nitric oxide when exposed to sunlight.

CFCs (chlorofluorocarbons) have no natural source, but were entirely synthesized for such diverse uses as refrigerants, aerosol propellants and cleaning solvents. Their creation was in 1928 and since then concentrations of CFCs in the atmosphere have been rising. Due to the discovery that they are able to destroy stratospheric ozone, a global effort to halt their production was undertaken and was extremely successful. So much so that levels of the major CFCs are now remaining level or declining.

Electric power plants are the single largest industrial source of some of the worst air pollutants. The Environmental Protection Agency estimates that more than 120 million Americans live in areas where the air is unhealthy. Yet the Bush administration's air pollution plan would gut existing health protections and do nothing to curb global warming.

2 comments:

Fantastic said...

air pollution have a causes, so what kind of largest of causes it is human or natural??? as I know, human do it more serious. so what do you think?

fathi adha

Fantastic said...

you can give all friend mew causes.thank because i know many causes air pollution. before this i just know 2 or 3 causes air pollution. so thanks for information...ikin.............