ABSTRACT
The apparent local and global increase of certain atmospheric trace gases has become a worldwide focus of discussion since all living organisms and ecosystems are affected by these dry and wet emissions and subjected together to atmospheric and stratospheric ‘‘global changes’’ (1). During the last 20 to 30 years we had to learn that organic gaseous emissions such as methane (stemming from ruminants) together with other trace gases in the air (sulfur dioxide, different oxides of nitrogen, resulting from combustion or rhizospheral bacteria) undergo extremely complex reaction chains, partially dependent on light as driving force, and produce a plethora of new componds that may either be toxic to animals and plants or have climate effects, or do both. Numerous symposia were held on this subject since the beginning of the awareness of the arising problems and a wealth of books have been published since then (2-11). In most of these reactions, oxidative processes and peroxides play a pivotal role, either as intermediates or as end products. This role of oxidative processes in air pollution had already been reported in the 19th century, when the production of acid rain was recognized as an oxidation by atmospheric hydrogen peroxide of sulfur dioxide stemming from coal combustion (12). Similarly, chlorophyll bleaching was described by the end of the 19th century as a process
catalyzed by oxidizing enzymes. Nevertheless we were greatly surprised by the overwhelming number of recent findings that oxygen toxicity is a dominant factor in general toxicological and pathological conditions.
