Air Air Pollution Air Pollution
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| Kids&Science Air Air Pollution Air Pollution |
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Air PollutionThe Most Important Air PollutantsAir pollution and its effects, like the greenhouse effect, acid rain, smog and the hole in the ozone layer are topics which are widely discussed these days. It is well known that our air is polluted with pollutants coming from different sources. But which substances are exactly responsible for air pollution, how are they formed and what are their effects? Carbon Dioxide CO2Carbon dioxide is the final product of respiration, but also of the burning of organic material. The natural balance between the generation of CO2 and its consumption by plants, which need it for photosynthesis, was disturbed by man by the burning of fossil fuels and the deforestation of vast stretches of forests. As a result, the CO2 content of the air is constantly on the rise. The problem is, that carbon dioxide is one of the gases called greenhouse gases, which retain heat in the atmosphere. A rise in CO2 will therefore most likely lead to an increase in the greenhouse effect, global warming and worldwide changes of the climate with far-reaching consequences. Apart from CO2, other gases like methane CH4, which is generated in the stomachs of ruminants during fermentation or in marshes, contribute to the greenhouse effect as well. Sulphur Dioxide SO2
Nitric Oxides NOxThe nitrogen oxides NO and NO2 are summed up as nitric oxides NOx, which are formed out of the nitrogen and the oxygen of the air at high temperatures. This happens during burning, for example in engines, but also due to lightning during thunderstorms. Together with water, the nitric oxides form nitric acid, and thus they also contribute to the formation of acid rain. Additionally, they are a precursor for ground level ozone. DustAnd let’s not forget various dust-like pollutants that are released by industries and traffic, which pollute the air as well. |
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Last Update: 2004-Feb-29 |
Sulphur dioxide is generated by burning fuels containing sulphur like coal or oil products, but is also released by volcanoes in nature. SO2 reacts with the moisture of the air giving sulphurous acid and sulphuric acid, which return to the ground with the rain. This acid rain, which leads to an acidification of soil and water, is the reason for forest dieback and does damage to buildings, since it dissolves lime and sandstone.