Organic anthropogenic gases

In the case of anthropogenic hydrocarbons in non-saline sediments and mixtures of organic compounds in soil the technique has been further refined by combining it with mass spectrometry (for further discussion see section 1.1.5.5 under gas chromatography-mass spectrometry). 

Sulfur dioxide is produced by both natural and anthropogenic sources. The most important of the natural sources are volcanic eruptions, which account for about 40 percent of all natural emissions of the gas. Since volcanic eruptions are episodic events, the amount of sulfur dioxide attributable to this source in any one year varies widely. Other natural sources of the gas are forest fires and other natural burns, biological decay, and certain metabolic processes carried out by living organisms, especially marine plankton and bacteria. Natural sources release about 27.5 million short tons (25 million metric tons) of sulfur dioxide per year. 

Anthropogenic Volatile Organic Compounds in Forest Areas of Northern and Southern Europe and a Remote Site of the Himalaya Region by High-Resolution Gas Chromatography-Mass Spectrometry, . /. Chromatogr., 643, 55-69 (1993b). 

In short, while the focus has been primarily on sulfuric and nitric acids as a source of acid deposition, it is clear that organic acids can also contribute significantly. The gas-phase concentrations of the simplest carboxylic acids, formic acid and acetic acid, are relatively high even in remote regions, of the order of a ppb. Both natural and anthropogenic sources have been... 

Huybrechts, T., Dewulf, J., Van Langenhove, H. (2003). State-of-the-art of gas chromatography-based methods for analysis of anthropogenic volatile organic compounds in estuarine waters, illustrated with the river Scheldt as an example. J. Chromatogr. A, 1000(1-2), 283-297. 

Ling N, Hickey CW, Burton GA. 1998. Are Antarctic marine organisms sensitive to anthropogenic pollutants NZ Nat Sci 23 106. 

Cavanagh et al. (37) made gas-chromatographic measurements of the organic content of the surface atmosphere at Point Barrow and found fractional part-per-billion levels of ethane, ethylene, butane, pentane, acetaldehyde, acetone, methanol, ethanol, benzene, and two unknown components, while n-butanol was found in the 10 ppb range. It is not known whether the butanol was present owing to contamination from an anthropogenic source or whether it was naturally present in the biosphere. 

Some VOCs are toxic and carcinogenic. Two main sources of VOCs can be distinguished natural and anthropogenic. Natural sources are the vegetation processes of certain organisms, assimilation processes, forest fires, volcanic or geyser activity, and natural gas release (ca. 30-60 million tons per year). Anthropogenic... 

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