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Air Pollution

airquali-graf-1.jpg Air pollution is a broad term applied to any agent (chemical, physical, biological or other) that modifies the natural characteristics of the atmosphere and has an effect in man or the environment. Worldwide air pollution is influencing the quality of life, while in addition is accounted responsible for deaths and various respiratory diseases. Setting of air pollution levels, to regulate air quality, as is the case of related EU regulations, has contributed to levering the negative impacts of air pollution by improving air quality.

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General Information


The most common sulphur oxide is sulphur dioxide (SO2). Sulphur trioxide (SO3) is an intermediate product during the manufacture of sulphuric acid (contact process). Sulphur dioxide is a colourless gas with a penetrating, choking odour. It dissolves readily in water to form an acidic solution (sulphurous acid).


Origin and use


Sulphur dioxide is a reducing agent and is used for bleaching and as a fumigant and food preservative. Large quantities of sulphur dioxide are also used in the contact process for the manufacture of sulphuric acid. It is also used in bleaching wool or straw, and as a disinfectant. Liquid sulphur dioxide has been used in purifying petroleum products. Sulphur dioxide was used as a blanketing gas in magnesium production to prevent its oxidation in air. This use was replaced some time ago by sulphur hexafluoride, which is essentially non-toxic (but an extremely potent greenhouse gas).


Major emissions


The main emission source of sulphur dioxide is the burning of fossil fuels. Power stations, oil refineries and other large industrial plants contribute to the majority of the total mass released. Domestic boilers, as well as natural sources such as active volcanoes and forest fires, release sulphur dioxide. Oxidation of other sulphur compounds (such as hydrogen sulphide) released into the atmosphere by natural and man-made processes provides another emission source. From 1970 to 1998 the amount of sulphur dioxide being released into the atmosphere annually has been reduced by 75%. This reduction was largely a result of the decreasing use of coal for power generation and its replacement by natural gas.


Source: European Pollutant Emission Register, hosted by the European Environment Agency (EEA). http://eper.cec.eu.int