Sekundärföroreningar

Sekundärföroreningar are chemical substances that are not directly emitted into the environment but are formed through chemical reactions involving primary pollutants or other environmental substances. These reactions can occur in the atmosphere, in water bodies, or in soil. Unlike primary pollutants, which are released directly from sources like industrial emissions or vehicle exhausts, secondary pollutants are a consequence of atmospheric chemistry or other environmental processes.

A common example of a secondary pollutant is ozone (O3) in the troposphere, also known as ground-level ozone. It is formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight. While stratospheric ozone is beneficial as it protects us from harmful UV radiation, tropospheric ozone is a significant component of smog and can cause respiratory problems and damage vegetation.

Another category of secondary pollutants includes various sulfates and nitrates. These are formed when sulfur dioxide (SO2) and nitrogen oxides (NOx), primary pollutants from burning fossil fuels, react with water, oxygen, and other chemicals in the atmosphere. These secondary pollutants are major contributors to acid rain, which can acidify lakes and streams, damage forests, and erode buildings. Peroxyacetyl nitrate (PAN) is another secondary pollutant found in photochemical smog, which can cause eye irritation and damage to plants. The formation and behavior of secondary pollutants are complex and depend on various environmental factors such as temperature, humidity, and the presence of catalysts.