Substances polluting the air

An air pollutant is a component which is able, either directly, or after relevant conversions occurring in the atmosphere, to damage or threaten living organisms and to affect adversely the environment. Depending on chemical and physical characteristics, we can divide substances polluting the air into several groups  

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The atmosphere is polluted either in the release of different substances into the air or during processes occurring directly in the air (e.g. chemical reactions). The substances polluting the air may be divided into primary and secondary ones, depending on the site of their production. In contrast to primary pollutants, which enter the atmosphere from natural sources or by the action of human activity, the secondary components are formed directly in the air during atmospheric reactions. These reactions occur as a result of mutual interactions between elements and compounds or by the action of different types of the energy. 

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