Gaseous pollutants
Impacts de l’énergie sur l’environnement

Gaseous pollutants are emitted during the direct combustion of fossil fuels. These are primary pollutants. They can interact with the environment to generate secondary pollutants. The main primary pollutants are carbon monoxide CO, sulfur oxides SO_x (SO₂ and SO₃), nitrogen oxides NO_x (NO, NO₂, N₂O, N₂O₅ and NO₃), particulates (soot particles and fine ash), unburned hydrocarbons.

• Carbon monoxide is produced by the incomplete combustion of fossil fuels. Most of it comes from transport, especially during cold starts. Vehicle exhaust gases can contain up to 10% carbon monoxide. This odorless gas is toxic to humans, since exposure for 4 hours to an airborne concentration of 1,000 ppm leads to certain death. The reason is that carbon monoxide has an affinity for the ferrous ions...