ABSTRACT
The organic species present in the atmosphere comprise gases, lipids and organic particles. Among the gases, the short chain alkanes and alkenes, aldehydes, ketones and acids are frequent. They originate mainly from spillage of petroleum-derived products as well as from combustion processes. Apart from methane, which is the major biogenic organic gas, a minor amount of volatiles also evolves from microbial activity and odoriferous plants, as for instance, isoprene and monoterpenes (Simoneit & Mazurek 1981).
