Air

Air pollution

Pollutants and their effects

Photochemical pollution

The “photochemical smog” is a typical form of pollution of all the main urban and industrial areas of the world. It occurs in or near areas with a high traffic density, in the presence of specific climatic conditions (no wind or weak winds, high temperatures, etc.), that cause the concentration of polluting gases to increase and prevent them from dispersing. In these areas, the concentrations of some gases (tropospheric ozone, carbon monoxide, particulate, VOC, nitrogen oxides, etc.) very often exceed the threshold values, above which there are risks for human health, farming and natural vegetation.