1. Natures, sources and impacts

Fumes are, by definition, gaseous discharges from combustion (heating, transport, incineration...) emitted into the atmosphere. They consist mainly of nitrogen (N ₂ ), oxygen (O ₂ ), carbon dioxide (CO ₂ ) and water vapor (H ₂ O _g ). In the fumes, however, we encounter compounds in lower concentrations, or even in trace amounts: dust, sulfur and nitrogen oxides, metals and volatile organic compounds (VOCs).